BEGIN:VCALENDAR METHOD:PUBLISH PRODID:www-math-fau-de//Events//DE VERSION:2.0 BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Claudio Dappiaggi (Pavia): tba UID:15888c87-95a4-4fcf-b80d-f690654598da DESCRIPTION:Claudio Dappiaggi (Pavia) DTSTART:20261210T151500Z DTEND:20261210T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Markus Fröb (FAU): Bounding relativ e entropy for non-unitary excitations in quantum field theory UID:1f56bc00-d515-411b-860c-f635395600e4 DESCRIPTION:Markus Fröb (FAU) Bounding relative entropy for non-unita ry excitations in quantum field theory Abstract: I show how one can us e the convexity of non-commutative L_p norms to bound the relative ent ropy between a faithful state on a von Neumann algebra and an arbitrar y excitation thereof. The results hold for general von Neumann algebra s\, including the local algebras of type III that are ubiquitous in qu antum field theory\, and do not require knowledge of the relative modu lar operator. As an application\, I show that for the chiral current o n a light ray\, the relative entropy between the vacuum and a dense se t of single-particle states is uniformly bounded. Joint work with Leon ardo Sangaletti\, based on https://arxiv.org/abs/2604.18383 DTSTART:20260702T141500Z DTEND:20260702T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Johanna Erdmenger (Würzburg): Recen t advances on diagnosing chaos with Krylov complexity UID:80a6636c-e73e-4be0-a0c1-6be27b4ad9c2 DESCRIPTION:Johanna Erdmenger (Würzburg) Recent advances on diagnosin g chaos with Krylov complexity Abstract: I will give a review of the c oncept of Krylov complexity and how it may be used to diagnose chaos i n quantum systems. Moreover\, applications to examples from both many- body physics and gauge/gravity duality will be presented. DTSTART:20260709T141500Z DTEND:20260709T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Fumihiko NAKANO (Tohoku): Random Mos aic Model UID:723a37f1-1c5e-4903-8a45-090f185fb861 DESCRIPTION:Fumihiko NAKANO (Tohoku) Random Mosaic Model Abstract : Ra ndom Mosaic model is a „\;superposition of free Laplacian and And erson model on l^2(Z)\, which has pp spectrum with an „\;extended state at one single point. We discuss the almost sure spectrum\, tran sport\, and the eigenvalue statistics. This is a joint work with Xu Xi a (CAS). DTSTART:20260716T141500Z DTEND:20260716T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Gerardo Franco Cordova\, (TU Braunsc hweig): Boundary Values of the Resolvent of Lattice Schrödinger Opera tors UID:8f15ba18-3b3a-49fd-9835-7d16e1ea7f4f DESCRIPTION:Gerardo Franco Cordova\, (TU Braunschweig) Boundary Values of the Resolvent of Lattice Schrödinger Operators Abstract: For gene ric periodic tight-binding Hamiltonians with matrix symbols\, we estab lish a limiting absorption principle. We also investigate the resolven t behavior near van Hove singularities and Weyl points. These results show how the local geometry of the energy bands and Fermi surfaces inf luences the spectral properties of periodic lattice Hamiltonians DTSTART:20261105T151500Z DTEND:20261105T171500Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Barbara Roos (GSSI\, L'Aquila): tba UID:6029432a-fd71-4b22-aba3-3d5ac7276288 DESCRIPTION:Barbara Roos (GSSI\, L’\;Aquila) DTSTART:20261112T151500Z DTEND:20261112T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Prof. Christian Hainzl\, (LMU): tba UID:4297a07c-8c17-42b3-a5f2-e8c8ea732f96 DESCRIPTION:Prof. Christian Hainzl\, (LMU) Abstract: DTSTART:20261119T151500Z DTEND:20261119T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Beatrice Costeri (Pavia): The Hadama rd parametrix on half-Minkowski with Robin boundary conditions: Fundam ental solutions and Hadamard states UID:1621903b-33e0-4230-b346-77ca16e52626 DESCRIPTION:Beatrice Costeri (Pavia) The Hadamard parametrix on half-M inkowski with Robin boundary conditions: Fundamental solutions and Had amard states Abstract: We study the construction of fundamental soluti ons and Hadamard states for a Klein-Gordon field in half-Minkowski spa cetime with Robin boundary conditions in d ge 2 spacetime dimensions. Extending the Robin-to-Dirichlet map of Bondurant and Fulling [J. Phys . A: Math. Theor. 38 7 (2005)] beyond the two-dimensional scenario\, w e express the advanced and retarded Green operators as convolutions wi th the inverse map’\;s kernel\, establishing their uniqueness and support properties. We then derive a local form for the associated Ha damard parametrix that captures boundary-reflected singularities and w e show that our solutions are consistent with this structure. Finally\ , we prove that this local Hadamard condition is equivalent to the glo bal one formulated via wave-front sets described in terms of generaliz ed broken bi-characteristics\, thus obtaining a Radzikowski-type resul t for half-Minkowski spacetime. Based on joint work with C.Dappiaggi\, B. A. Juárez-Aubry and R.D. Singh —\; Ann. Henri Poincaré (202 6)\, https://doi.org/10.1007/s00023-026-01702-2. DTSTART:20260430T141500Z DTEND:20260430T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Lukas Reichmann (FAU): The excitatio n spectrum of Bose gases in the Gross-Pitaevskii regime UID:f5a044e5-86f4-4a7e-a4a8-4090961d3bd1 DESCRIPTION:Lukas Reichmann (FAU) The excitation spectrum of Bose gase s in the Gross-Pitaevskii regime Abstract: I will talk about how to ap ply a strategy developed by Nam and Triay to prove the low-energy exci tation spectrum for Bose gases in the Gross-Pitaevskii regime in the 3 -dimensional box with side length 1. This extends previous results by Boccato-Brennecke-Cenatiempo-Schlein and Hainzl-Schlein-Triay to inter action potentials that are not necessarily compactly supported or sphe rically symmetric. This is based on joint work with A. Triay. DTSTART:20260507T141500Z DTEND:20260507T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Andrea Pizzamiglio (Pavia): Scaling Limits of Quantum Cellular Automata UID:4ac05727-9b72-4d39-9ec7-c8ca4e0712ed DESCRIPTION:Andrea Pizzamiglio (Pavia) Scaling Limits of Quantum Cellu lar Automata Abstract: We discuss the continuum limit of a 1+1-dimensi onal quantum cellular automaton (QCA) with quartic fermionic interacti on\, which serves as a digital counterpart of the Thirring model. A ce ntral question in mathematical physics and quantum simulation is how i nteracting quantum field theories can be rigorously defined or emerge as scaling limits of fundamentally discrete microscopic dynamics. QCA are unitary\, locality-preserving discrete dynamics that naturally mod el quantum many-body systems in quantum information and quantum simula tion. Adopting Wilson’\;s perspective\, we formulate quantum fiel d theory as a coherent family of lattice models connected across scale s by the renormalization group. Our renormalization procedure is a rea l-time Heisenberg-picture version of Wilson-Kadanoff renormalization\, implemented operator-algebraically through wavelet embeddings of obse rvables. We show how\, under suitable renormalization conditions and e mbeddings\, the automaton converges to continuum field dynamics in the free Dirac vacuum representation. Based on ongoing joint work with Al exander Stottmeister and Tobias J. Osborne. DTSTART:20260521T141500Z DTEND:20260521T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Albert Much (Uni Leipzig): Semiclass ical Einstein Equations from QFT via modular theory UID:f5f6081c-b02d-4737-8f31-0077e1fc48a8 DESCRIPTION:Albert Much (Uni Leipzig) Semiclassical Einstein Equations from QFT via modular theory Abstract: Jacobson showed that the Einste in equations follow from the thermodynamic relation δQ = T δS\, wher e Q is the heat flux\, T the temperature and S the entropy\, applied t o local Rindler horizons\, using quantum field theoretic input such as the Unruh effect. This raises the question of whether gravity can be derived entirely within quantum field theory (QFT). In this talk\, I p resent a QFT-based extension of Jacobson’\;s argument formulated in terms of relative entropy\, a well-defined and finite entropic quan tity for local algebras in QFT. Approximating small spacetime regions by Minkowski space\, we compute the relative entropy between the vacuu m and coherent excitations of a Klein-Gordon field on a local Rindler horizon using modular theory. The resulting expression is governed by the stress-energy tensor and encodes the energy flux across the horizo n. Identifying the variation of relative entropy with the area variati on of the horizon then reproduces the semiclassical Einstein equations \, providing a quantum-information-theoretic perspective on gravitatio nal dynamics. This talk is based on joint work with Philipp Dorau (pub lished in Phys. Rev. Lett. 136\, 091602 (2026)\, https://arxiv.org/abs /2510.24491). DTSTART:20260611T141500Z DTEND:20260611T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Flore Kunst (MPI/FAU): Exceptional n on-Hermitian topology UID:71b4661b-2a7e-4b50-87b6-0968cc224a95 DESCRIPTION:Achtung\, Seminar findet ausnahmsweise an einem Mittwoch s tatt! Flore Kunst (MPI/FAU) Exceptional non-Hermitian topology Abstrac t: While most theoretical research focusses on studying systems isolat ed from their surroundings\, we take a more realistic perspective by t aking environmental effects such as gain and loss of particles explici tly into account. As a consequence\, we arrive at so-called non-Hermit ian descriptions. This approach is highly relevant to quantum optics\, electronics\, mechanical metamaterials\, nonconservative biological s ystems as well as quantum systems\, to name a few. In recent years\, n on-Hermiticity has been investigated in the context of topology\, whic h is a branch of mathematics describing properties that can only chang e step-wise and which has found many applications in physics. Adding t he ingredients of non-Hermitian approaches and topology together has r evealed a dramatic enrichment of the phenomenology of topological phas es and resulted in a new\, rapidly expanding cross-disciplinary resear ch field. In this talk\, I will provide an overview of the field focus sing on fundamental aspects\, experimental realizations and I will bri efly touch on applications. DTSTART:20260617T123000Z DTEND:20260617T140000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Jan Mazac (FAU): Diffraction of Hats and Spectres (and mathematical theory of diffraction in a nutshell) UID:49e60f11-0c0b-42a1-bcdd-3c3c49d9cbec DESCRIPTION:Jan Mazac (FAU) Diffraction of Hats and Spectres (and math ematical theory of diffraction in a nutshell) Abstract: The mathematic al theory of diffraction is a great tool to understand a certain type of order in infinite objects\, such as discrete point sets. This fact was known to physicists and crystallographers for periodic structures already more than a hundred years ago. Since the late ’\;90\, the re has been a very solid way to treat also non-periodic structures\, a nd\, in the talk\, we will briefly review this theory. The recently di scovered tiles Hat and Spectre provide nice examples of such structure s\, as they can tile the plane in an aperiodic way only. In the talk\, we show that the resulting tiling is quasiperiodic and can be obtaine d as a projection of a periodic structure in four dimensions. In other words\, the tiling is mutually locally derivable with a model set. It is known that such sets have a pure-point diffraction spectrum. We th en provide the images of the diffraction spectrum\, and we discuss the method to obtain them. DTSTART:20260625T141500Z DTEND:20260625T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Tim Rotheneder (FAU): Positivity Dom ains and Coverings of Compactly Causal Symmetric Spaces UID:c35d9eb2-290d-4abe-927a-58c18e463de0 DESCRIPTION:Tim Rotheneder (FAU) Positivity Domains and Coverings of C ompactly Causal Symmetric Spaces Abstract: Given a compactly causal sy mmetric Lie algebra $(mathfrak{g}\,tau\,C)$ and an Euler element $hin mathfrak{g}$ as infinitesimal data and an associated causal symmetric space $(G\,H\,tau\,C)$ with $M:= G/H$\, we discuss how the topology of the positivity region $W_M^+(h)$ depends on the global choice of $G$ and $H$. Eventually\, we apply our theoretical results to the anti-de Sitter example\, i.e. $mathfrak{g} = mathfrak{so}_{2\,d}(R)$\, $tau$ i s conjugation with $I_{1\,d+1}$ and $C$ is the forward light cone. DTSTART:20251218T151500Z DTEND:20251218T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Arnaud Triay (LMU München): The fre e energy of dilute Bose gases at low temperature UID:388aa9cd-d632-48b8-bad9-44ebbc1633ae DESCRIPTION:Arnaud Triay (LMU München) The free energy of dilute Bose gases at low temperature Abstract: In their celebrated paper of 1957\ , Lee\, Huang and Yang computed the excitation spectrum of dilute Bose gases. I will talk about a series of recent works where we justified this formula by proving an expansion of the free energy for low temper ature hence capturing the effects of the quantum fluctuations. This is based on joint works with S. Fournais\, T. Girardot\, F. Haberberger\ , C. Hainzl\, L. Junge\, L. Morin\, P.T. Nam\, M. Olivieri\, B. Schlei n\, R. Seiringer DTSTART:20260115T151500Z DTEND:20260115T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Benjamin Hinrichs (Paderborn): On In frared and Ultraviolet Problems for Polaron Models UID:e5ca364e-60e2-4457-8ab9-2c22734eaa9e DESCRIPTION:Benjamin Hinrichs (Paderborn) On Infrared and Ultraviolet Problems for Polaron Models Abstract: Polaron models describe linear i nteractions between quantum matter and bosonic quantum fields\, which appear in various applications ranging from quantum optics (spin boson model) over effective models for impurities in many-body systems (Fr öhlich or Bose polarons) to simplified versions of quantum field theo ries (Nelson model). Both low-energy (infrared) and high-energy (ultra violet) bosons give rise to singularities. While these singularities d iffer in their physical origin and mathematical implications\, they al so exhibit analogous mathematical structures. We discuss older results on the implications of IR and UV singularities and a novel wavefuncti on renormalization scheme\, suitable to address both infrared and ultr aviolet problems\, especially for supercritical interactions beyond re ach for simpler renormalization techniques. The latter is based on joi nt work with Marco Falconi and Javier Valentín Martín. DTSTART:20260122T151500Z DTEND:20260122T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Flore Kunst (Max Planck Institute fo r the Science of Light\, Erlangen): Exceptional non-Hermitian topology UID:d0010a7a-bfd2-433f-abac-4ad053f20c22 DESCRIPTION:Flore Kunst (Max Planck Institute for the Science of Light \, Erlangen Exceptional non-Hermitian topology Abstract: While topolog ical phases of matter have predominantly been studied for isolated Her mitian systems\, a recent shift has been made towards considering thes e phases in the context of non-Hermitian Hamiltonians. Non-Hermitian t opological phenomena reveal an enrichment of the phenomenology of topo logical phases\, and forms a rapidly growing new cross-disciplinary fi eld. In this talk\, we will see that non-Hermitian Hamiltonians\, whic h come about due to\, e.g.\, gain and loss\, feature many exotic prope rties\, which are radically different from their Hermitian counterpart s. In particular\, I will focus on our recent work on higher-order exc eptional points\, which are truly non-Hermitian degeneracies\, the rol e played by symmetries and similarities\, and present explicit toy mod els to illustrate our findings. Additionally\, I will discuss the role of exceptional points in nonlinear Kerr resonators. Abstract: DTSTART:20260128T133000Z DTEND:20260128T150000Z LOCATION:01.255-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Carmine de Rosa (Trento): Achronal L ocalization and Representation of the Causal Logic from Conserved Curr ents UID:daec759f-eb5c-4eaa-8000-ad3eb84af3d8 DESCRIPTION:Carmine de Rosa (Trento) Achronal Localization and Represe ntation of the Causal Logic from Conserved Currents Abstract: In this seminar\, I will present and discuss recent achievements [1\, 2\, 3\, 4] concerning the theory of achronal localization derived from conserv ed currents\, as well as the representation theory of the Causal Logic of Minkowski spacetime. Due to the one-to-one correspondence between (covariant) achronal localizations and (covariant) representations of the causal logic thus\, apparently for the first time\, a covariant re presentation of the causal logic for an elementary relativistic quantu m mechanical system has been achieved. Localizations are gained out of covariant conserved currents computing their flux passing through ach ronal surfaces. This general method applies to the probability density currents with causal kernel regarding the massive scalar boson. Simil arly one derives the covariant family of representations of the causal logic related to the stress energy tensor of the massive scalar boson . To prove these results\, it is necessary to develop certain techniqu es of geometric measure theory concerning sets with almost Lipschitz b oundaries. References [1] Moretti\, V. (2023)\, On the relativistic sp atial localization for massive real scalar Klein-Gordon quan- tum part icles. Letters in Mathematical Physics 113\, 66 [2] De Rosa C.\, Moret ti V. (2024)\, Quantum particle localization observables on Cauchy sur faces of Minkowski spacetime and their causal properties Letters in Ma thematical Physics 114\, 24 [3] Catrigiano D.P.L.\, De Rosa C.\, Moret ti V. (2025)\, Achronal localization and representation of the causal logic from conserved current\, application to massive scalar boson arX iv:2501.12699 [4] Castrigiano D.P.L. (2025)\, Achronal localization\, representations of the causal logic for massive sys- tems. Lett Math P hys 115\, 25 . ∗University of Trento\, Italy and INFN-TIFPA\; e-mail : carmine.derosa@unitn.it DTSTART:20260129T151500Z DTEND:20260129T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Nathan Métraud (BCAM): Non-commutat ive evolution equation and application in many-body quantum theory. UID:a4e11365-6dcd-47b1-a754-11c8f8a487ad DESCRIPTION:Nathan Métraud (BCAM) Non-commutative evolution equatin a nd application in many-body quantum theory Abstract: We study the Broc ket-Wegner flow\, an evolution equation on non-commutative spaces of o perators. It defines a nonlinear\, operator-valued dynamics that is pa rticularly delicate in the presence of unbounded operators. We discuss the main analytical difficulties arising from non-commutativity and u nboundedness\, and show how they can be overcome in two important clas ses of many-body quantum Hamiltonians: quadratic fermionic Hamiltonian s and generalized spin-boson models. In these cases\, despite unbounde d initial data\, intrinsic structures ensure well-posedness of the flo w. Using this flow as a dynamical tool\, we obtain new diagonalization results in many-body quantum theory (joint work with Jean-Bernard Bru ). DTSTART:20260205T151500Z DTEND:20260205T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, David Damanik (Rice University): Ret urn to Wonderland UID:aea3d43c-b5d5-4a33-973b-8e21484c97a7 DESCRIPTION:David Damanik (Rice University) Return to Wonderland Abstr act: Barry Simon’\;s Wonderland Theorem exhibited the genericity and ubiquity of singular continuous spectrum in the study of Schrödin ger operators. In this talk we revisit this issue and in particular th e following two questions: Is there a version of the Wonderland Theore m for dynamically defined potentials? and What is the generic spectral type of a Schrödinger operator with a bounded potential? We will exp lain the answers to these questions and how they arise. This is joint work with Artur Avila. DTSTART:20251106T163000Z DTEND:20251106T173000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik: Réamonn Ó Buachalla (Prag): Noncomm utative Kahler Structures UID:dcc22906-f586-4879-a583-df280b2a9ec8 DESCRIPTION:Réamonn Ó Buachalla (Prag) Noncommutative Kahler Structu res Abstract: We begin by reviewing the general framework of different ial calculi over *-algebras. Building on this\, we introduce the notio n of a complex structure\, understood as a noncommutative analogue of the decomposition of complexified differential forms on a complex mani fold. We then proceed to the concept of a (positive definite) noncommu tative Kähler structure and outline several fundamental results that arise from its existence\, including the Lefschetz decomposition\, the Kähler identities\, the Hodge decomposition\, and the refinement of de Rham cohomology into Dolbeault cohomology. If time permits\, we wil l conclude with a discussion of the motivating example of the standard quantum sphere and its Dolbeault-Dirac spectral triple. DTSTART:20251113T151500Z DTEND:20251113T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Pysik\, Christian Sadel (FAU): General transf er matrix techniques and absolutely continuous spectrum UID:ac5fc5a5-d8c5-4cf8-82f9-e420750b5f5d DESCRIPTION:Christian Sadel (FAU) General transfer matrix techniques a nd absolutely continuous spectrum Abstract: DTSTART:20251127T151500Z DTEND:20251127T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematisch Physik\, Malte Leimbach (Bonn): Compact quantu m metric spaces and spectral truncations UID:304b2372-8335-44d2-81e0-b553a1dc94f7 DESCRIPTION:Malte Leimbach (Bonn) Compact quantum metric spaces and sp ectral truncations Abstract: Starting from Connes‘\; distance for mula\, Rieffel generalized Lipschitz constants of functions to so-call ed Lip-norms of bounded operators. Lip-norms induce metrics on state s paces and a crucial requirement is that these metrics induce the weak* topology\, in which case one speaks of a compact quantum metric space . There are various quantum versions of Gromov–\;Hausdorff distan ce allowing for considering questions about convergence of compact qua ntum metric spaces. In this talk I will focus on compact quantum metri c spaces modeled on operator systems and Kerr–\;Li’\;s opera tor Gromov–\;Hausdorff distance. I will discuss some convergence results related to the spectral truncations put forward by Connes̵ 1\;van Suijlekom. DTSTART:20251204T151500Z DTEND:20251204T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Lauritz van Luijk (Perimeter Institu te): Entanglement in von Neumann Algebraic Quantum Information Theory UID:3aef0996-a8b7-4670-b740-e2cb76873533 DESCRIPTION:Lauritz van Luijk (Perimeter Institute) Entanglement in vo n Neumann Algebraic Quantum Information Theory Abstract: I will presen t results from a recent series of works with Alexander Stottmeister\, Reinhard F. Werner\, and Henrik Wilming in which we study bipartitions of quantum systems with an infinite number of degrees of freedom from an information-theoretic perspective. Our goal is to understand the i nterplay between information-theoretic properties of the physical syst ems and algebraic properties of the von Neumann algebras describing th em. I will present two developments: (1) A bijective correspondence be tween the classification of factors into types and subtypes and a set of operational entanglement properties. For instance\, Connes‘\; classification of type III factors corresponds to the smallest achieva ble error when trying to ‚\;embezzle‘\; entanglement from th e system. (2) A result from my PhD thesis showing that the von Neumann algebraic description of subsystems can be derived from a set of mode l-independent operational axioms. DTSTART:20251211T151500Z DTEND:20251211T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Simone Rademacher (LMU München): La rge deviations for Bose-Einstein condensates UID:e765edab-3eb3-4a07-a337-2ff63ac08855 DESCRIPTION:Simone Rademacher (LMU München) Large deviations for Bose -Einstein condensates Abstract: Bose-Einstein condensation (BEC) is a special phenomenon of trapped Bose gases at low temperatures where a m acroscopic fraction of the particles occupies the same one-particle qu antum state\, called condensate. This talk concerns a probabilistic ap proach to BEC: We consider the ground state of an interacting Bose gas on the three-dimensional unit torus\, known to exhibit BEC. For weak interactions in the mean-field regime\, we show that bounded one-parti cle operators satisfy large deviation estimates and compute the rate f unction up to second order. For singular interactions in the Gross-Pit aevskii regime\, we prove an upper bound for the tails of the quantum depletion\, the operator counting the number of particles outside the condensate\, based on an explicit asymptotic formula its generating fu nction. The talk is based on joint works with Nils Behrmann\, Christia n Brennecke and Phan Thanh Nam. DTSTART:20250710T141500Z DTEND:20250710T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Ian Koot: Relative positions of Half -sided Modular Inclusions UID:b1cb52a2-f1a0-4d23-9033-739edd8947ff DESCRIPTION:Ian Koot Relative positions of Half-sided Modular Inclusio ns Abstract: Half-sided Modular Inclusions are inclusions of standard subspaces where the modular groups of the two standard subspaces satis fy some ’\;nice‘\; relations. Recently we proved that inclus ions of two standard subspaces that lie as Half-sided Modular Inclusio ns in a larger standard subspace can be fully characterized by inclusi ons of associated complex subspaces. We use these results\, together w ith the representation theory of the Canonical Commutation Relations a nd the theory of Hardy spaces\, to clarify how two half-sided modular inclusions in the same standard subspace can relate to each other. DTSTART:20250723T130000Z DTEND:20250723T150000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Francesca Arici (Leiden): KK duality for Temperley--Lieb subproduct systems UID:ec177ce7-4ccb-4599-984e-8ce75450b550 DESCRIPTION:Francesca Arici (Leiden) KK duality for Temperley–\;L ieb subproduct systems Abstract: The notion of KK-duality is a noncomm utative analogue of the Spanier-Whitehead duality. It induces natural isomorphisms between the K-theory and K-homology of the dual C∗-alge bras. Notable examples of noncommutative C*-algebras satisfying KK-dua lity are Cuntz–\;Krieger algebras. In this talk\, we will describ e a quantum analogue of the result of Kaminker and Putnam on CuntzR 11\;Krieger algebras. Specifically\, we consider the Cuntz–\; Pim sner algebras of subproduct systems defined by Temperley-Lieb polynomi als\, as defined by Habbestad–\;Neshveyev. These algebras can be thought of as algebras of functions on algebraic subsets of noncommuta tive spheres. Joint work with D. Gerontogiannis and S. Neshveyev. DTSTART:20250723T220000Z DTEND:20250723T220000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Chris Bourne (Nagoya): Interfaces of discrete quantum systems UID:0cf56356-f97c-4019-b0db-7a90f646567a DESCRIPTION:Chris Bourne (Nagoya) Interfaces of discrete quantum syste ms Abstract: Loosely speaking\, an interface describes a spatial mixin g of several systems described by a C*-algebra of observables such tha t these mixed dynamics are not felt ‚\;at infinity‘\;. Build ing from work by Măntoiu\, we give a mathematical description of (dis crete) interfaces using C*-modules and (discrete) crossed products. Se veral examples will be given as well as spectral and index-theoretic p roperties. DTSTART:20250827T220000Z DTEND:20250827T220000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Dragan Marković (FAU): Chaos and op erator dependent anomalous transport in semiclassical\,Bose-Hubbard ch ains UID:740a86a8-7936-4fc5-93a9-79e83d5a8999 DESCRIPTION:Dragan Marković (FAU) Chaos and operator dependent anomal ous transport in semiclassical Bose-Hubbard chains Abstract: We invest igate anomalous transport and chaotic dynamics in the semiclassical on e-dimensional Bose-Hubbard chain using the Truncated Wigner Approximat ion with quantum corrections. At early times\, the system exhibits rob ust superdiffusion characterized by universal\, quantized exponents go verned primarily by the initial state\, largely independent of model p arameters or the strength of chaos. This anomalous regime persists eve n in long chains and reflects a special scaling symmetry of the Hamilt onian. At later times\, a crossover to normal diffusion emerges\, whic h is most stable when nonintegrability is strong\, leading to homogene ous states\; for weaker nonintegrability\, long-lived oscillations and inhomogeneities survive despite strong chaos. The coexistence of fast (angle) and slow (action) variables provides a natural framework to i nterpret the transport properties through free energy functionals: whi le quenched ensembles fail to equilibrate\, annealed ensembles capture the effective late-time behavior. Together\, these results highlight anomalous diffusion as a universal\, early-time phenomenon distinct fr om prethermalization\, smoothly evolving into conventional hydrodynami c transport at long times. 1. Superdiffusion\, normal diffusion and ch aos in semiclassical Bose-Hubbard chains\, Phys. Rev. E 112\, 024211\; arXiv: 2502.19584 2. Chaos and anomalous transport in a semiclassical Bose-Hubbard chain\, Phys. Rev. E 109\, 034213\; arXiv: 2308.14720 3. Thermodynamic formalism and anomalous transport in 1D semiclassical B H chain\, arXiv preprint: 2312.17008 DTSTART:20251023T141500Z DTEND:20251023T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Evgeny Korotyaev (Northeast Normal U niversity\, Changchun\, China): Spectral invariants for vector periodi c NLS UID:383b04bd-a166-403e-80dc-e15c7aaad411 DESCRIPTION:Evgeny Korotyaev (Northeast Normal University\, Changchun\ , China) Spectral invariants for vector periodic NLS Abstract. Firstly \, we discuss the various properties of periodic Zkharov-Shabat operat or\, associated with scaler periodic NLS. We describe the main results and techniques. Secondly\, we discuss first order operators with a pe riodic 3×\;3 matrix potential on the real line. This operator is t he Lax operator for the periodic vector NLS equation. The spectrum of the operator covers the real line and it is union of the spectrum of m ultiplicity 3\, separated by intervals (gaps) of multiplicity 1. We pr ove the following: · The corresponding 2 or 3-sheeted Riemann surface is described. · Necessary and sufficient conditions are given when t he Riemann surface is 2-sheeted. In the case of the 2-sheeted Riemann surface the solution of vector NLS equation is determined in terms of solutions of scalar NLS equations. · One constructs an entire functio n\, which is negative on the spectrum of multiplicity 3 and is positiv e on its gaps. · The conformal mapping of the upper half plane on the domain on the upper half plane is constructed and the main properties are This conformal mapping has asymptotics at high energy where coeff icients are constants of motion. As a corollary we obtain the estimate of potentials in terms of gap lengths. · Finally the Borg type resul t is obtained. DTSTART:20251106T150000Z DTEND:20251106T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Gandeeb Bhattarai (Tübingen): Funct ional Central Limit Theorem (FCLT) in Quantum many body systems UID:285d10a1-b8b5-4c54-b595-d760dbf7b142 DESCRIPTION:Gandeeb Bhattarai (Tübingen) Functional Central Limit The orem (FCLT) in Quantum many body systems Abstract: DTSTART:20250515T141500Z DTEND:20250515T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Jean-Bernard Bru (BCAM): Exchange In teractions and Cuprate Superconductivity UID:be8ff631-599a-4d14-a67b-e8f00724a70f DESCRIPTION:Jean-Bernard Bru (BCAM) Exchange Interactions and Cuprate Superconductivity Abstract: In this talk\, we will explain the effect of quantum interactions exchanging different types of particles. We wi ll consider a system made of two fermions and one boson\, in order to study the effect of such an off-diagonal interaction term. We will in particular show the existence of exponentially localized dressed bound fermion pairs. We will give particular attention to the regime of ver y large on-site (Hubbard) repulsions\, because this situation is relev ant for cuprate superconductors. Indeed\, in the meantime\, we will ex plain the high-temperature superconductivity of cuprates and apply our model to such physical systems. DTSTART:20250522T141500Z DTEND:20250522T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Matthias Keller (Potsdam): On Landis conjecture for positive Schrödinger operators on graphs UID:a15eb57d-6e1c-476c-95ad-d06d46d4a3fd DESCRIPTION:Matthias Keller (Potsdam) On Landis conjecture for positiv e Schrödinger operators on graphs Abstract: Landis conjecture is conc erned with growth bounds for harmonic functions of Schrödinger operat or whose potential in absolute value is bounded by one. We study this problem for real potentials and positive Schrödinger operators on gen eral graphs and in the Euclidean lattice in particular. (This is joint work with Ujjal Das and Yehuda Pinchover.) DTSTART:20250605T141500Z DTEND:20250605T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Phan Thành Nam (LMU): Bogoliubov-Le e-Yang theory for the mean-field Bose gas at positive temperatures UID:cd899372-dac1-4b48-abc2-acb01af4d2b8 DESCRIPTION:Phan Thành Nam (LMU) Bogoliubov-Lee-Yang theory for the m ean-field Bose gas at positive temperatures Abstract: I will discuss r ecent joint work with Andreas Deuchert and Marcin Napiórkowski on the rigorous justification of a version of Bogoliubov theory proposed by Lee and Yang in 1958 to describe the interacting Bose gas at positive temperatures\, comparable to the critical temperature of the Bose-Eins tein phase transition. We consider the homogeneous mean-field Bose gas on the 3D torus and prove a trace-norm approximation for the grand ca nonical Gibbs state\, which also yields precise formulas for correlati on functions. Our result goes beyond the standard quasi-free approxima tion\, and a key ingredient of our proof is an abstract correlation in equality based on Stahl’\;s theorem. DTSTART:20250612T141500Z DTEND:20250612T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Nicolò Drago (Genua): Classical and quantum KMS states on spin lattice systems UID:532278ad-ddb1-49e5-ae6d-bba53b7e0b04 DESCRIPTION:Nicolò Drago (Genua) Classical and quantum KMS states on spin lattice systems Abstract: We study the classical and quantum KMS conditions within the context of spin lattice systems. Specifically\, we define a strict deformation quantization (SDQ) for a S^2-valued spi n lattice system over Z^d generalizing the renown Berezin SDQ for a si ngle sphere. This allows to promote a classical dynamics on the algebr a of classical observables to a quantum dynamics on the algebra of qua ntum observables. We then compare the notion of classical and quantum thermal equilibrium by showing that any weak*-limit point of a sequenc e of quantum KMS states fulfils the classical KMS condition. In short\ , this proves that the semiclassical limit of quantum thermal states d escribes classical thermal equilibrium\, strengthening the physical in terpretation of the classical KMS condition. Finally we provide two su fficient conditions ensuring uniqueness of classical and quantum KMS s tates: The latter are based on a version of the Kirkwood-Salzburg equa tions adapted to the system of interest. As a consequence we identify a mild condition which ensures uniqueness of classical KMS states and of quantum KMS states for the quantized dynamics for a common sufficie ntly high temperature. Joint work with L. Pettinari and C.J.F. van de Ven. DTSTART:20250626T141500Z DTEND:20250626T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Alexander Schenkel (Nottingham): C*- categorical prefactorization algebras for superselection sectors and t opological order UID:3cd83b4b-4e24-41a6-a626-6b8ad9805d76 DESCRIPTION:Alexander Schenkel (Nottingham) C*-categorical prefactoriz ation algebras for superselection sectors and topological order Abstra ct: I will present a geometric framework to encode the algebraic struc tures on the category of superselection sectors of an algebraic quantu m field theory on the n-dimensional lattice Z^n. I will show that\, un der certain assumptions which are implied by Haag duality\, the monoid al C*-categories of localized superselection sectors carry the structu re of a locally constant prefactorization algebra over the category of cone-shaped subsets of Z^n. Employing techniques from higher algebra\ , one extracts from this datum an underlying locally constant prefacto rization algebra defined on open disks in the cylinder R^1 x S^{n-1}. While the sphere S^{n-1} arises geometrically as the angular coordinat es of cones\, the origin of the line R^1 is analytic and rooted in Haa g duality. The usual braided (for n=2) or symmetric (for n>2) monoidal C*-categories of superselection sectors are recovered by removing a p oint of the sphere and using the equivalence between E_n-algebras and locally constant prefactorization algebras defined on open disks in R^ n. The non-trivial homotopy groups of spheres induce additional algebr aic structures on these E_n-monoidal C*-categories\, which in the simp lest case of Z^2 is given by a braided monoidal self-equivalence arisi ng geometrically as a kind of `holonomy‘\; around the circle S^1. This talk is based on joint work with Marco Benini\, Victor Carmona a nd Pieter Naaijkens [arXiv:2505.07960]. DTSTART:20250703T141500Z DTEND:20250703T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Wilhelm Kroschinsky (Bonn): The time -stability of Bose-Einstein\,Condensates in the Gross-Pitaevskii\,regi me UID:ca33dfac-5268-4b26-895e-156eaca15a7b DESCRIPTION:Wilhelm Kroschinsky (Bonn) The time-stability of Bose-Eins tein Condensates in the Gross-Pitaevskii regime Abstract: We revisit t he problem of time-stability of Bose-Einstein condensate (BEC) of an i nitially trapped 3D system of bosons in the Gross-Pitaevskii regime. W e prove that the system still exhibits BEC when the trap is switched o ff\, and the effective dynamics is governed by the solution of the tim e- dependent Gross-Pitaevskii equation. Our main strategy is to contro l renormalized excitation number operators with respect to the Schröd inger dynamics 𝑡 ↦ → 𝑒−𝑖𝐻𝑁 𝑡 \, rather than co ntrolling the number of excitations with respect to a suitable excitat ion dynamics 𝑡 ↦ → 𝑒−𝐵𝑡 𝑒−𝑖𝐻𝑁 𝑡 . DTSTART:20250130T151500Z DTEND:20250130T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Lars Koekenbier (FAU): Transfer matr ix analysis of non-hermitian Hamiltonians: asymptotic spectra and topo logical eigenvalues UID:11c6054b-d8b8-47dc-8958-f54004b5caf1 DESCRIPTION:Lars Koekenbier (FAU) Transfer matrix analysis of non-herm itian Hamiltonians: asymptotic spectra and topological eigenvalues Abs tract: Transfer matrix techniques are used to provide a new proof of W idom’\;s results on the asymptotic spectral theory of  nite blo ck Toeplitz matrices. Furthermore\, a rigorous treatment of the skin e  ect\, spectral outliers\, the generalized Brillouin zone and the bu lkboundary correspondence in such systems is given. This covers chiral Hamiltonians with topological eigenvalues close to zero\, but no line -gap. DTSTART:20250206T151500Z DTEND:20250206T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Yasu Kawahigashi (Tokyo): Tensor net works in two-dimensional topological order and operator algebras UID:b732c18d-e90b-487a-8a89-0057dfbb3728 DESCRIPTION:Yasu Kawahigashi (Tokyo) Tensor networks in two-dimensiona l topological order and operator algebras Abstract: Certain 4-tensors appear in mathematical studies of 2-dimensional topological order rece ntly. We identify them with bi-unitary connections that appear in subf actor theory in operator algebras and are variants of quantum 6j-symbo ls. We then translate various notions in the two studies in both direc tions and have deeper understanding of their mathematical structures. DTSTART:20250313T151500Z DTEND:20250313T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Ian Koot (FAU): Inclusions in Half-S ided Modular Inclusions UID:758b6dfa-0a29-4133-afcf-9e1eeb8dae31 DESCRIPTION:Ian Koot (FAU) Inclusions in Half-Sided Modular Inclusions Abstract: DTSTART:20250320T151500Z DTEND:20250320T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Anne van Grinsven (LMU): Mean-Field Approximation of the Ground State Energy of a Quasi-2D Bose Gas UID:2cd6dbbe-9b6b-4998-8a0e-86919fde245a DESCRIPTION:Anne van Grinsven (LMU) Mean-Field Approximation of the Gr ound State Energy of a Quasi-2D Bose Gas Abstract: We discuss a rigoro us derivation of the mean-field approximation for the ground state ene rgy of a quasi-two-dimensional Bose gas. This system consists of a tra pped Bose gas with a potential that is highly confining in one directi on\, leading to effective two-dimensional behavior. Working in the mea n-field regime\, we consider systems where particles interact weakly b ut frequently. The argument builds on the method developed by Lewin\, Nam and Rougerie for three-dimensional trapped systems. The main focus is the adaptation of this approach to account for the strong confinem ent and the associated dimensional reduction. We conclude by commentin g on possible extensions\, including the convergence of reduced densit y matrices and the incorporation of dipole-dipole interactions. DTSTART:20250424T141500Z DTEND:20250424T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Markus Fröb (Leipzig): How to compu te modular Hamiltonians UID:5384d1e5-ac30-4c24-b975-ada02f6448ca DESCRIPTION:Markus Fröb (Leipzig) How to compute modular Hamiltonians Abstract: The Tomita-Takesaki theory of modular automorphisms of von Neumann algebras has attracted renewed interest in recent years in con nection with the definition of entropies in quantum field theory. I wi ll present a short introduction to the theory\, in which the main obje ct of interest is the modular Hamiltonian. I then explain how one can compute this Hamiltonian explicitly in various situations\, in particu lar for relativistic fermions in 1+1 dimensions. Based on arXiv:2312.0 4629\, arXiv:2406.19360\, arXiv:2411.09696 and arXiv:2501.09669. DTSTART:20250508T141500Z DTEND:20250508T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Michael Heins (Würzburg): A Holomor phic Perspective of Strict Deformation Quantization UID:1b8a660d-4114-47ed-88fd-666d2e8b349a DESCRIPTION:Michael Heins (Würzburg) A Holomorphic Perspective of Str ict Deformation Quantization Abstract: Classical mechanical systems ma y be modelled by means of Poisson algebras\, which physically arise as the observables corresponding to the system. The quantization scheme called Deformation Quantization establishes a second product on the ob servable algebra\, a so-called star product. Imposing a classical and semiclassical limit condition with respect to a positive parameter ℏ then intertwines the classical with the quantum multiplication. To fa cilitate the construction\, it is both customary and advisable to take a step back and pass to formal power series with coefficients in the classical algebra and indeterminant ℏ. One thus speaks of a formal d eformation quantization. This talk is about overcoming the formal char acter of the resulting theory\, which is a necessity for physically me aningful statements\, and accounts for the fact that ℏ is a physical constant and not a free parameter. As the formal star product is\, in particular\, itself given by a power series\, this naturally leads in to the realm of holomorphic functions\, both in finite and infinite di mensions. After briefly reviewing the formal situation\, we discuss a recently proposed notion of strict deformation quantization and invest igate how one can use established results from complex analysis to thi nk about these objects. Along the way\, we shall illustrate the abstra ct ideas in the setting of standard ordered quantization on the cotang ent bundle of the real line. DTSTART:20241128T151500Z DTEND:20241128T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Tom Stoiber\, (Yeshiva University): Higher-order Topological Insulators and K-theory UID:531ca0e0-4665-4f2d-80fb-bcb1d1581751 DESCRIPTION:Tom Stoiber\, (Yeshiva University) Higher-order Topologica l Insulators and K-theory Abstract: Topological insulators are materia ls that are insulating in their interior but exhibit protected surface states\, a phenomenon that is mathematically well-understood through the use of C*-algebras and operator K-theory. In higher-order topologi cal insulators\, all faces of a crystal are insulating\, while surface states appear only at boundaries of higher codimension\, such as hing es or corners. For so-called intrinsic topological insulators the exis tence of these states is independent of boundary conditions but requir es spatial symmetries like mirror\, rotational\, or inversion symmetry . Since the topological protection emerges only in the infinite volume limit\, we need to construct C*-algebras that describe symmetric infi nite crystals with various boundary configurations. These algebras nat urally admit cofiltrations based on the codimensions of the boundaries \, leading to spectral sequences in equivariant K-theory. We then demo nstrate that the classification and phenomenology of higher-order topo logical insulators align seamlessly with this formalism. Specifically\ , the higher differentials in the spectral sequence identify precisely the classes of intrinsic higher-order topological insulators and thei r associated surface states. DTSTART:20241219T151500Z DTEND:20241219T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Christiaan van de Ven: Large deviati ons in mean-field quantum spin systems UID:ddb20df4-6ff1-4268-abf8-493ba09cf900 DESCRIPTION:Christiaan van de Ven Large deviations in mean-field quant um spin systems Abstract: Continuous fields of C*-algebras form an imp ortant ingredient for describing emergent phenomena\, such as phase tr ansitions and spontaneous symmetry breaking. In this talk\, I consider the continuous C*-bundle generated by increasing symmetric tensor pow ers of the complex (elltimesell) matrices\, which can be interpreted a s abstract description of mean-field theories defining the macroscopic limit of infinite quantum systems. Within this framework I discuss th e principle of large deviations for the local Gibbs state in the high temperature regime and characterize the limit of the ensuing logarithm ic generating function. To this end\, it has proved necessary to demon strate the existence of a semiclassical analog of the Baker-Campbel-Ha usdorff formula\, defined in terms of a series of nested Poisson brack ets. DTSTART:20250109T151500Z DTEND:20250109T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Ram Band: The Dry Ten Martini Proble m for Sturmian Schrödinger Operators UID:30d9f3f4-93c1-4e7d-8a07-8b69cfd94bf7 DESCRIPTION:Ram Band The Dry Ten Martini Problem for Sturmian Schrödi nger Operators Abstract: Are all gaps there?\, asked Mark Kac in 1981 during a talk at the AMS annual meeting\, and offered ten Martinis for the answer. This led Barry Simon to coin the names the Ten Martini Pr oblem (TMP) and the Dry Ten Martini Problem for two related problems c oncerning the Almost-Mathieu operator. The TMP is about showing that t he spectrum of the Almost-Mathieu operator is a Cantor set. The Dry TM P is about the values that the integrated density of states (IDS) atta ins at the spectral gaps. The gap labelling theorem predicts the possi ble set of values which the IDS may attain at the spectral gaps. The D ry TMP is whether or not all these values are attained\, or equivalent ly\, are all gaps there? We present an affirmative solution to the Dry Ten Martini Problem for Sturmian Hamiltonians –\; this is proven in a joint work with Siegfried Beckus and Raphael Loewy. In a joint w ork with Gilad Sofer\, we study families of Sturmian operators on metr ic and discrete graphs. We show how their gap labels are characterized and what would be the corresponding Dry Ten Martini Problem for those . DTSTART:20250116T151500Z DTEND:20250116T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Gerardo Franco Cordova: Analytic Pro perties of the Scattering Matrix of Discrete Schrödinger Operators UID:28c01cbc-0296-4694-b973-4082c40ef9f6 DESCRIPTION:Gerardo Franco Cordova Analytic Properties of the Scatteri ng Matrix of Discrete Schrödinger Operators Abstract: We develop a sc attering theory for discrete Schrödinger operators. We represent the scattering matrix in terms of special solutions to the eigenvalue equa tion\, known as Jost solutions. This representation facilitates the an alytic extension of certain coefficients of the scattering matrix\, en abling a detailed study of their analytic properties. Furthermore\, we connect these analytic properties of the scattering matrix to the spe ctral properties of the Hamiltonian\, ultimately deriving a version of the Levinson formula. DTSTART:20250123T151500Z DTEND:20250123T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Daniela Cadamuro (Leipzig): The mass ive modular Hamiltonian in the case of bosons and fermions und Jakob H edicke (Montreal): On spaces of light rays and contact structures UID:29711b43-87dd-4a37-955d-28a5e8c53f15 DESCRIPTION:Daniela Cadamuro (Leipzig) The massive modular Hamiltonian in the case of bosons and fermions Abstract: The Tomita-Takesaki modu lar operator for local algebras plays an important role in quantum fie ld theory\, and more recently in the study of relative entropy. Howeve r\, the explicit expression of this operator\, except for the case of wedges\, is difficult to describe mathematically. We have obtained num erical results for the form of the modular Hamiltonian for a double co ne in a massive scalar free field in (1+1)- and (3+1)-dimensional Mink owski space\, which shows how it differs from the wedge case\, in part icular regarding the dependence of the modular Hamiltonian on the mass of the field. We also obtained results for the free massive Majorana fermions in 1+1 dimensions in the cases of a single and two double con es\, and point out the differences with the bosonic case. Jakob Hedick e (Toronto) On spaces of light rays and contact structures Abstract: A s first observed in the works of Penrose and Low\, in many cases the s pace of light rays of a Lorentzian spacetime can be naturally equipped with the structure of a smooth contact manifold. In these cases the c ontact geometry of the space of light rays has strong connections to t he causality of the underlying Lorentzian manifold. After an introduct ion to the relevant notions from contact- and Lorentzian geometry\, we will discuss criteria that ensure the space of light rays to be a con tact manifold and we will determine its contact structure in several e xamples. DTSTART:20240711T141500Z DTEND:20240711T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Melchior Wirth (IST Wien): Operator- Valued Twisted Araki-Woods Algebras UID:dc26a9d0-773f-47fe-9adc-4f8a28c6fa57 DESCRIPTION:Melchior Wirth (IST Wien) Operator-Valued Twisted Araki-Wo ods Algebras Abstract: I will introduce the class of operator-valued t wisted Araki-Woods algebras\, which are second quantization von Neuman n algebras built on certain Hilbert bimodules over a base von Neumann algebra. When the base algebra is the field of complex numbers\, this class includes the q-Gaussian algebras and free Araki-Woods factors\, and for arbitrary base algebras Shlyakhtenko’\;s von Neumann alge bras generated by operator-valued semicircular variables fall into thi s class. In the case when the base algebra is a type I factor\, I will present how a disintegration theory for the underlying Hilbert bimodu les leads to a decomposition as a tensor product of the base algebra a nd a scalar-valued twisted Araki-Woods algebra. Moreover\, operator-va lued twisted Araki-Woods algebras come with a natural weight\, and I w ill discuss the associated modular theory as well as some sufficient c riteria for factoriality. This is joint work with Rahul Kumar R. DTSTART:20240718T141500Z DTEND:20240718T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Luca Giorgetti (Rom): Crossing symme try and Fourier transforms UID:3b7531db-5775-47db-9360-dd86faf367df DESCRIPTION:Luca Giorgetti (Rom) Crossing symmetry and Fourier transfo rms Abstract: Crossing symmetry is an invariance property of scatterin g amplitudes involving (pairs of) particles and their TCP conjugates. Recently\, see arXiv:2212.02298\,crossing symmetry has been reformulat ed as an analytic extension property ofcertain functions defined using Tomita-Takesaki modular theory. In the talk\, I will introduce a line ar map on bounded operators on the tensor square of a given complex Hi lbert space\, called the crossing map\, whose fixed points describe cr ossing symmetry. I describe its basic properties and\, among its many surprising relations with other mathematical objects\, I will describe how it turns out to be a special case of the subfactor theoretical Fo urier transform (which generalizes\, e.g.\, the ordinary Fourier trans form for finite abelian groups). Joint work with R. Correa da Silva an d G. Lechner\, arXiv: 2402.15763 DTSTART:20240722T120000Z DTEND:20240722T140000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Diana Taschetto (Utrecht): The Dual Dynamical Foundation of Orthodox Quantum Mechanics UID:6f1dbfd2-2dfe-4ec7-b615-ce5bc20579b1 DESCRIPTION:Diana Taschetto (Utrecht) The Dual Dynamical Foundation of Orthodox Quantum Mechanics Abstract: In his groundbreaking The Mathem atical Foundations of Quantum Mechanics von Neumann asked the question \, why quantum mechanics has a dual dynamics (unitary evolution and co llapse postulate)? He could not find a proper solution to it\, i.e.\, a solution based on dynamical principles. In this talk\, we shall pres ent such a solution\, certified by the golden rule of physics that the dynamics of a theory must follow from the action principle. The reaso n why quantum mechanics has this peculiar dual dynamics is that the th eory is based\, as we shall demonstrate\, on a peculiar dual action. DTSTART:20240930T121500Z DTEND:20240930T140000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Azam Jahandideh (Poznan): Stochastic quantization of two-dimensional $P(Phi)$ Quantum Field Theory UID:6167b7d3-399f-49bb-993e-60296a21f1eb DESCRIPTION:Azam Jahandideh (Poznan) Stochastic quantization of two-di mensional $P(Phi)$ Quantum Field Theory Abstract: We give a simple and self-contained construction of the $P(Phi$ Euclidean Quantum Field Th eory in the plane and verify the Osterwalder-Schrader axioms: translat ional and rotational invariance\, reflection positivity and regularity . In the intermediate steps of the construction\, we study measures on spheres. In order to control the infinite volume limit\, we use the p arabolic stochastic quantization equation and the energy method. To pr ove the translational and rotational invariance of the limit measure w e take advantage of the fact that the symmetry groups of the plane and the sphere have the same dimension. Joint work with Paweł Duch and W ojciech Dybalski. DTSTART:20241017T141500Z DTEND:20241017T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Lea Boßmann (FAU): Focusing dynamic s for 2d Bose gases in the instability regime UID:041b3f3f-8e88-46f4-bb71-2f182c41b0fa DESCRIPTION:Lea Boßmann (FAU) Focusing dynamics for 2d Bose gases in the instability regime Abstract: We consider the dynamics of a 2d Bose gas with singular attractive interactions in the instability regime\, where the corresponding focusing nonlinear Schrödinger equation (NLS ) has a blow-up. We show that the evolution of the condensate is effec tively described by this NLS for all times before the blow-up. Moreove r\, we prove the validity of the Bogoliubov approximation for the fluc tuation dynamics\, resulting in a norm approximation of the many-body dynamics. This is joint work with Charlotte Dietze and Phan Thành Nam . DTSTART:20241024T141500Z DTEND:20241024T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, LQP 49 Workshop UID:1a450fe1-1100-4c3e-b270-3997f62317e7 DESCRIPTION:LQP 49 Workshop Dates: 7-9 November 2024 Topics: This work shop is dedicated to mathematical quantum physics and more specificall y quantum field theory. The topics covered here will hence be concentr ated on quantum field theory (on Minkowski space or curved spacetimes\ , axiomatic\, constructive\, rigorous\, Euclidean versions)\, as well as more general mathematical quantum physics\, operator algebras (in p articular\, von Neumann algebras and subfactors)\, quantum information theory\, and noncommutative geometry. DTSTART:20241107T130000Z DTEND:20241107T180000Z LOCATION:H13 DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Thomas Creutzig (FAU): Towards logar ithmic conformal field theory UID:1b8d8afc-bed9-44aa-8e55-9a2ea7262dd0 DESCRIPTION:Thomas Creutzig (FAU) Towards logarithmic conformal field theory Abstract: A vertex operator algebra is the algebraic notion of chiral (and anti-chiral) algebra in two-dimensional conformal field th eory. VOAs are an established subject of mathematics in its own right\ , but connecting to the physics of two-dimensional CFT is still diffic ult. This difficulty arises as VOA is of algebraic nature while the ob servables in CFT\, the correlation functions\, are of analytic nature. Representation theory of modern VOAs almost exclusively is non semi-s imple\, which should lead to logarithmic CFT\, that is CFTs whose corr elation functions can have logarithms. I will define full logarithmic VOAs\, which have exactly the features that one wants a genus zero log arithmic CFT to have\, and will give an example. DTSTART:20241121T151500Z DTEND:20241121T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Davide Lonigro (FAU): Double or noth ing: a Kolmogorov extension theorem for multitime (bi)probabilities in quantum mechanics UID:b6f30bfe-3503-4418-88f5-d69178c808fc DESCRIPTION:Davide Lonigro (FAU) Double or nothing: a Kolmogorov exten sion theorem for multitime (bi)probabilities in quantum mechanics Abst ract: The multitime probability distributions obtained by repeatedly p robing a quantum system via the measurement of an observable generally violate Kolmogorov’\;s consistency property. Therefore\, one can not interpret such distributions as the result of the sampling of a si ngle trajectory. We show that\, nonetheless\, they do result from the sampling of one pair of trajectories. In this sense\, rather than give up on trajectories\, quantum mechanics requires to double down on the m. To this purpose\, we prove a generalization of the Kolmogorov exten sion theorem that applies to families of complex-valued bi-probability distributions (that is\, defined on pairs of elements of the original sample spaces)\, and we employ this result in the quantum mechanical scenario. Based on arXiv:2402.01218. Joint work with F. Sakuldee\, Ł. Cywiński\, D. Chruściński\, and P. Szańkowski. —\; DTSTART:20240418T141500Z DTEND:20240418T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Edoardo D'Angelo (Genua): Functional Renormalization and the Nash-Moser theorem UID:fdb0dc48-d192-4000-b827-a713d477aa0d DESCRIPTION:Edoardo D’\;Angelo (Genua) Functional Renormalization and the Nash-Moser theorem Abstract: The Renormalization Group (RG) E quation determines the flow of the effective action under changes in a n artificial energy scale\, which roughly corresponds to the scale of the system under consideration. I report on a rigorous construction of a non-perturbative RG flow for the effective action in Lorentzian man ifolds. I give the main ideas of a proof of local existence of solutio ns for the RG equation\, when a suitable Local Potential Approximation is considered. The proof is based on an application of the renown Nas h-Moser theorem. Time permitting\, I also discuss an application of th e RG equation to the non-perturbative renormalizability of quantum gra vity. DTSTART:20240425T141500Z DTEND:20240425T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Hermann Schulz-Baldes (FAU): Transfe r matrix analysis of non-hermitian Hamiltonians: asymptotic spectra an d topological eigenvalues UID:97e2029f-0f1b-4503-9730-69f3c2f9a675 DESCRIPTION:Hermann Schulz-Baldes (FAU) Transfer matrix analysis of no n-hermitian Hamiltonians: asymptotic spectra and topological eigenvalu es Abstract: Transfer matrix techniques are used to provide a new proo f of Widom’\;s results on the asymptotic spectral theory of finit e block Toeplitz matrices. Furthermore\, a rigorous treatment of the s kin effect\, spectral outliers\, the generalized Brillouin zone and th e bulk-boundary correspondence in such systems is given. This covers c hiral Hamiltonians with topological eigenvalues close to zero\, but no line-gap. This is joint work with Lars Koekenbier. DTSTART:20240502T141500Z DTEND:20240502T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Yoh Tanimoto (Rom): Lattice construc tion of QFT and formal mathematics UID:fd595d03-7731-4c47-9d3a-54da0cbe0996 DESCRIPTION:Yoh Tanimoto (Rom) Lattice construction of QFT and formal mathematics Abstract: I give an overview of the strategy of Balaban-Di mock and our recent attempts of constructing Euclidean field theory. I n relation with it\, I talk about my recent experience with proof assi stant. DTSTART:20240523T141500Z DTEND:20240523T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Yuto Moriwaki (Riken\, Tokyo): Confo rmal block\, braided operad and factorization UID:81681775-0531-4f23-8759-0428c7b0625e DESCRIPTION:Yuto Moriwaki (Riken\, Tokyo) Conformal block\, braided op erad and factorization Abstract: From representations of a vertex oper ator algebra\, D-modules (conformal blocks) on configuration spaces of the Riemann sphere are constructed. We show that compositions of conf ormal blocks are consistent with the operad structure of the configura tion spaces. This gives an alternative proof of the result of Huang-Le powky that the representation category of a regular vertex operator al gebra has a structure of braided tensor category. DTSTART:20240606T141500Z DTEND:20240606T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Dietmar Bisch (Vanderbilt): New subf actors with small Jones index UID:c851426b-3c59-48c6-ba3c-c4257660776e DESCRIPTION:Dietmar Bisch (Vanderbilt) New subfactors with small Jones index Abstract: Since Vaughan Jones introduced the theory of subfacto rs in 1983\, it has been an open problem to determine the set of Jones indices of irreducible\, hyperfinite subfactors. Not much is known ab out this set. My student Julio Caceres and I have recently shown that certain intersting indices between 4 and 5 are realized by new hyperfi nite subfactors with Temperley-Lieb-Jones standard invariant. This lea ds to a conjecture regarding Jones‘\; problem. Our construction i nvolves commuting squares\, a graph planar algebra embedding theorem\, and a few tricks that allow us to avoid solving large systems of line ar equations to compute invariants of our subfactors. I will give some background to make the talk accessible to non-experts. DTSTART:20240620T141500Z DTEND:20240620T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Fernando Lledó (Madrid): Examples o f finite dimensional approximations in C*-algebras UID:0c8e3e18-b874-4e21-ab2e-2a0f19c4419a DESCRIPTION:Fernando Lledó (Madrid) Examples of finite dimensional ap proximations in C*-algebras Abstract: Motivated by the shocking Banach -Tarski paradox and\, in particular\, by Foelner type approximations o f amenable groups\, I will present finite dimensional matrix approxima tions in two classes of operator algebras: –\; The resolvent alge bra introduced by Buchholz and Grundling in 2008 to give an alternativ e bounded operator approach to the canonical commutation relations (CC R) in quantum mechanics. –\; The uniform Roe algebras of an inver se semigroup\, where the inverse semigroup is viewed as a metric space . In this talk I will emphasize the importance of examples. The result s presented are included in the recent publications [1] F. Lledó and D. Martínez\, *A note on commutation relations and finite dimensional approximations\,* Expositiones Mathematicae *40* (2022) 947-960. [2] F. Lledó and D. Martínez\, *The uniform Roe algebra of an inverse se migroup*\, Journal of Mathematical Analysis and Applications *499 *(20 21) 124996. [3] P.Ara\, F. Lledó and D. Martínez\, Amenability and p aradoxicality in semigroups and C*-algebras\, J. Funct. Anal. *279* (2 020) 108530 DTSTART:20240704T141500Z DTEND:20240704T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Arnold Neumaier (Wien): Coherent Qua ntization II: Causal groups and quantum fields UID:41da02ba-b37c-41b9-aa6a-230a4a118ed6 DESCRIPTION:Arnold Neumaier (Wien) Coherent Quantization II: Causal gr oups and quantum fields Abstract: This is the second of three lectures on coherent quantization and field theory to be given 11.-18.12.2023 in Erlangen (Germany). Causal groups are a new class of mathematical o bjects abstracted from the concept of dynamical C^*-algebras for quant um field theories introduced by Buchholz and Fredenhagen in their pape r Comm. Math. Phys. 377 (2020)\, 947-969. Unlike these authors (who ob tain their dynamical C^*-algebras from an analysis of causal perturbat iion theory) we motivate causal groups in a fully nonperturbative way from the consideration of classical discrete-time dynamical systems. T his gives an intuitive understanding of the properties later assumed a xiomatically for causal groups over causal spaces (generalizing Minkow ski spacetime). Each causal group over Minkowski space gives rise to a particular dynamical C^*-algebra. The dynamical C^*-algebras of Buchh olz and Fredenhagen arise from abstract causal groups defined by gener ators and relations. We show how to construct causal groups over causa l spaces having a Tomonaga-Schwinger structure associated with an appr opriate classical many-fingered time dynamics. This gives a clear geom etric meaning to the new concept. Their unitary representations give n onperturbative constructions of nonrelativistic and relativistic quant um field theories. Conditions are given under which the Haag-Kastler a xioms or the Wightman axioms can be established. This reduces the rigo rous construction of realistic quantum field theories such as QED or Q CD to the (still unsettled) construction of unitary representations of causal groups with the properties defining QED or QCD. A constructed QFT can be identified with a particular perturbatively defined one (su ch as QED or QCD) by performing aposteriori causal perturbation theory to lowest (1 loop) order. This lecture is essentially independent of the first lecture. The slides of the lecture will pr DTSTART:20231214T151500Z DTEND:20231214T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Adriano Chialastri (SISSA\, Trieste) : On entanglement measures in quantum field theory: von Neumann entrop y and Bell's inequalities UID:8027b68f-dc8c-45a1-b9b2-c5967dbe00e0 DESCRIPTION:Adriano Chialastri (SISSA\, Trieste) On entanglement measu res in quantum field theory: von Neumann entropy and Bell’\;s ine qualities Abstract: Entanglement as a topic has its origins in Einstei n\, Podolsky and Rosen’\;s 1935 work\, which sparked a decades-lo ng debate with its theoretical turning point in Bell’\;s 1964 wor k\, where the so-called Bell’\;s inequalities were born. However\ , throughout the years\, there has been a continuous interest in entan glement measures within the context of quantum field theory (QFT)\, wh ere different quantities like von Neumann entropy and relative entropy have long been studied. In this talk\, we will discuss about entangle ment measures within the formalism of algebraic QFT\, which provides a solid mathematical background for them. In particular\, we will analy ze von Neumann entropy\, with all its problems in QFT\, and its relati ons with maximal Bell correlation\, which is an entanglement measure q uantifying the violation of Bell’\;s inequalities. This talk is b ased on a joint work with S. Carpi (University of Rome Tor Vergata). DTSTART:20231221T151500Z DTEND:20231221T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Daan Janssen (York): Characteristic renormalization and applications to black hole formation UID:b4d4fb0a-aa15-47ca-b1ae-ef28dd35aee2 DESCRIPTION:Daan Janssen (York) Characteristic renormalization and app lications to black hole formation Abstract: We present a regularizatio n prescription for Hadamard two-point functions defined on the boundar y of a lightcone\, which can be used to analyze renormalized quantitie s for linear scalar fields in a curved background. This can be applied to formulate the semi-classical Einstein equations as a characteristi c initial value problem. Furthermore\, we shall discuss how these tool s may be used to estimate backreaction effects of quantum fields near gravitationally collapsing bodies and study formation of horizons and singularities in semi-classical gravity. DTSTART:20240111T151500Z DTEND:20240111T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Martin Ravn (München): Spectral Est imates for Fermionic n-Body Operators - Old and New UID:226066e5-4aee-4a6d-92db-f18c8bf80392 DESCRIPTION:Martin Ravn (München) Spectral Estimates for Fermionic n- Body Operators –\; Old and New Abstract: We consider bounds on th e eigenvalues of the n-body operators associated to fermionic N-partic le states. We review the classic norm estimates of Yang\, and present a recent estimate on the Hilbert-Schmidt norm of 2-body operators and their truncated versions. The Hilbert-Schmidt estimate is interesting since it is of the same order as the optimal norm estimate\, O(N). Thi s implies that although a fermionic 2-body operator can have eigenvalu es of size ~N\, it can not have too many large eigenvalues. DTSTART:20240118T151500Z DTEND:20240118T161500Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Romeo Brunetti (Trento): Algebraic s tructures and relations in the dynamical algebras approach to quantum field theory UID:0f2af691-eddc-4dff-9bf8-eafbdcd6598a DESCRIPTION:Romeo Brunetti (Trento)) Algebraic structures and relation s in the dynamical algebras approach to quantum field theory Abstract: In this talk I wish to present some established and new ideas in the C*-Dynamical Algebra formalism of Buchholz and Fredenhagen. In particu lar\, I’\;ll concentrate on new relations induced by solutions of interacting equations of motion (work in progress with Klaus Fredenha gen). DTSTART:20240125T151500Z DTEND:20240125T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Christian Sadel (Chile): Transfer ma trices and absolutely continuous spectrum for l-channel unitary operat ors UID:115924fd-1a10-42ac-92c5-f7b7f77717cf DESCRIPTION:Christian Sadel (Chile) Transfer matrices and absolutely c ontinuous spectrum for l-channel unitary operators Abstract: Based on the work on scattering zippers we develop a unitary analogue to one- a nd l-channel Hermitian operators with 2l by 2l transfer matrices. Then we obtain an analogue of Carmona’\;s spectral averaging formula and obtain criteria for absolutely continuous spectrum. Joint work wit h O. Bourget\, G. Moreno and A. Taarabt. DTSTART:20240201T151500Z DTEND:20240201T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Thomas Thiemann (FAU Physik): On rep resentations of the hypersurface deformation algebroid of quantum grav ity UID:1e34a823-605b-426a-8d16-180f29eee26d DESCRIPTION:Thomas Thiemann (FAU Physik) On representations of the hyp ersurface deformation algebroid of quantum gravity Abstract: Quantum G ravity (QG)\, understood as a Quantum Field Theory (QFT) of General Re lativity (GR)\, faces mathematical challenges that go beyond those of QFT in curved spacetime (CST). In this talk we focus on the hypersurfa ce deformation algebroid (HDA) which in the classical theory encodes t he Einstein equations. Implementing the quantum dynamics leads to the analysis of representations thereof by operators in QG. After an intro duction to those concepts\, we show that non-trivial representations o f the HDA exist in a weak coupling limit of GR in 3+1 dimensions with 2 propagating\, self-interacting polarisations. DTSTART:20240208T151500Z DTEND:20240208T170000Z LOCATION:Übung 5 / 01.254-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik: Giuseppe Di Giulio (Uni Würzburg) Sy mmetry-resolved modular correlation functions in free fermionic theori es UID:0611eb85-1aa2-4223-a82a-912d03b786f7 DESCRIPTION:Giuseppe Di Giulio (Uni Würzburg) Symmetry-resolved modul ar correlation functions in free fermionic theories Abstract: Recently there has been a huge research activity on the interplay between symm etries and entanglement\, exploiting the block-diagonal structure of t he reduced density matrix (RDM) in each charge sector. The goal of thi s talk is to study how the presence of a global U(1) charge affects th e modular flow\, a central object in the algebraic description of quan tum field theory. Roughly speaking\, the modular flow is given by a ge neralized time evolution induced by a RDM of a given spatial region. I will discuss the symmetry resolution of the modular flow and the modu lar correlation function of U(1)-invariant operators. I will provide a consistent definition of symmetry-resolved modular flow defined for a local algebra of operators associated with a sector with a fixed char ge. I will also discuss the symmetry-resolved modular correlation func tions\, showing that they satisfy the KMS condition in each symmetry s ector. In order to complement this analysis with an example\, I will p rovide a toolkit for computing the symmetry-resolved modular correlati on function of the charge density operator in free fermionic theories. I will show that\, in a 1 + 1-dimensional free massless Dirac field t heory\, this quantity is independent of the charge sector at leading o rder in the ultraviolet cutoff expansion. This feature can be regarded as an equipartition of the modular correlation function. DTSTART:20230720T141500Z DTEND:20230720T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Luca Giorgetti (Rom): Fusion categor y and hypergroup actions on conformal nets UID:5924b22e-eaa9-438f-b1b1-7a72ec9992ce DESCRIPTION:Luca Giorgetti (Rom) Fusion category and hypergroup action s on conformal nets Abstract: Groups of automorphisms of a conformal n et (the operator algebraic description of chiral CFT) naturally give r ise to subnets (subtheories)\, the so-called group orbifolds. Moreover \, automorphisms can be regarded as the ordinary global symmetries in the conformal net setting. We describe a generalization of these by me ans of unital completely positive (UCP) maps of the net (a sort of gen eralized non-invertible global symmetries of the net) obtained in a se ries of works in collaboration with M. Bischoff and S. Del Vecchio. In the talk I will restrict to completely rational conformal nets\, wher e hypergroups of UCP maps (instead of groups of automorphisms) are cap able of describing arbitrary subnets of a given net. I will recall som e background of conformal nets\, their representations\, and report on some new explicit formulas for such UCP actions\, relating hypergroup s of UCP maps with certain unitary fusion category actions on conforma l nets. DTSTART:20231019T141500Z DTEND:20231019T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Alexander Cerjan: An Operator-Based Approach to Topological Physics:\,Band Structures and Bloch Eigenstate s not Required UID:5b91bc95-03bf-4c65-9d7d-50af5a7f6865 DESCRIPTION:Alexander Cerjan An Operator-Based Approach to Topological Physics: Band Structures and Bloch Eigenstates not Required Abstract: Over the past two decades\, the study of topological properties in ph ysical systems has generated significant excitement\, as such systems can realize robust boundary-localized states that have a wide range of applications. However\, the theoretical frameworks that have been pre viously used to understand these phenomena are inextricably tied to ba nd theory\, usually requiring a system’\;s Bloch eigenstates or a projection onto the occupied subspace. Thus\, the many successes of t opological band theory also serve to highlight the current fundamental challenges facing the field\, such as the difficulties in studying to pology in aperiodic systems\, non-linear and interacting systems\, met allic systems\, and quantitatively accounting for finite size effects. In this talk\, I will present an operator-based framework for topolog ical physics that makes use of a system’\;s real-space descriptio n without the need to calculate its band structure or Bloch eigenstate s. Instead\, this framework is based on the system’\;s spectral l ocalizer\, and provides a set of local markers\, protected by local ga ps\, for every symmetry class in every physical dimension. I will disc uss how this operator-based framework can be used to identify topology in non-interacting metals and gapless heterostructures\, and show rec ent experimental observations of bulk-boundary correspondence in a top ological acoustic metal metamaterial. Moreover\, I will discuss how th is framework can be directly applied to nonlinear systems and realisti c photonic systems (i.e.\, Maxwell’\;s equations). This work is p art-funded by Sandia National Laboratories (SNL). SNL is managed and o perated by NTESS under DOE NNSA contract DE-NA0003525. References: [1] W. Cheng*\, A. Cerjan*\, S.-Y. Chen\, E. Prodan\, T. A. Loring\, and C. Prodan\, Revealing topology in metals using exper DTSTART:20231027T113000Z DTEND:20231027T133000Z LOCATION:Max-Planck-Institut für die Physik des Lichts\, Staudtstr. 2 DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Matthias Lesch (Bonn): Rearrangement Lemma\, divided differences and the multivariate holomorphic function al calculus UID:0dfe0905-3613-40a9-9f47-75d849f0bd4e DESCRIPTION:Matthias Lesch (Bonn) Rearrangement Lemma\, divided differ ences and the multivariate holomorphic functional calculus Abstract: T he so called Rearrangement Lemma is a technical device in the context of heat trace expansions on noncommutative spaces resp. for operators with noncommutative leading symbol. A couple of years ago I gave a sys tematic treatment and discussed the link to the classical divided diff erence formalism. In this talk I would like to recast the issue from t he point of view of the multivariate holomorphic functional calculus. The latter has a rich history and is of some interest in its own as it is by no means just a straightforward generalization of the usual one -variable case. I will review this history and give some elementary ap plications to noncommutative versions of Newton interpolation and Tayl or formulas as well as a holomorphic version of the rearrangement lemm a. The talk is based on an ongoing project with Luiz Hartmann from Sao Carlos\, Brazil. DTSTART:20231109T151500Z DTEND:20231109T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Nicolai Rothe (Technische Universit ät Berlin): Cosmological solutions to the semiclassical Einstein equa tion with Minkowski-like vacua UID:f790ce9c-44a6-4a3a-8fac-52c77620e6db DESCRIPTION:Nicolai Rothe (Technische Universität Berlin) Cosmologica l solutions to the semiclassical Einstein equation with Minkowski-like vacua Abstract: We will discuss some newly found solutions to the ful l massless semiclassical Einstein equation (SCE) in a cosmological set ting. After a short introduction to the relevant notions we present th e SCE in a particular shape which allows for the construction of certa in vacuum states for a free\, massless scalar field. These states may be viewed as as the least possible generalization of the Minkowski vac uum to general (cosmological) space-times. In this setting\, solving t he SCE breaks down into solving a certain ODE which can be approached numerically and\, at least generically\, we obtain solutions that well fit physical expectations. Moreover\, these solutions indicate dark e nergy as a quantum effect back-reacting on cosmological metrics. Since in our model m=Λ=0\, this may not be traced back to the usual\, obvi ous dark-energy/cosmological constant effect of a quantum field. Also we will shortly discuss some more physical problems that can be solved by our model. DTSTART:20231116T151500Z DTEND:20231116T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Leonardo Sangaletti (Leipzig): An L4 quantum energy inequality in the thermal sector UID:200adc21-474f-4753-b458-16b129ddd792 DESCRIPTION:Leonardo Sangaletti (Leipzig) An L4 quantum energy inequal ity in the thermal sector Abstract: Energy density and its positivity properties represent a fundamental subject in classical and quantum ph ysics. In this talk\, we will investigate this topic in the thermal re presentation of a free massive quantum scalar field. After a brief rev iew of the fundamental mathematical tools at the base of this work\, w e will construct the GNS representation of our QFT induced by a state at thermal equilibrium (KMS). Therein\, we will identify the generator of the time evolution and its spatial density. The symmetry between t he particles and holes makes evident the impossibility for a lower bou nd of the expectation value of the energy density in this representati on. In order to tackle this problem\, we will investigate and extend s ome results of modular theory and non-commutative Lp spaces. In this w ay\, we obtain a general result concerning the expectation value of an operator affiliated to a von Neumann algebra. Finally\, the proven re sults are used to derive an L4 state dependent non-trivial QEI. DTSTART:20231207T151500Z DTEND:20231207T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik: Paolo Meda (Trento): The Semiclassica l Einstein Equations and the Stability of Linearized Solutions UID:39ae7e25-e909-4590-ba47-2b96b79c222b DESCRIPTION:Paolo Meda (Trento) The Semiclassical Einstein Equations a nd the Stability of Linearized Solutions Abstract: The semiclassical f ormulation of gravity is discussed in the framework of algebraic quant um field theory in curved spacetimes. The main topic of the talk is th e Semiclassical Einstein Equations\, which describe the backreaction o f a quantum field on spacetime geometry. In the first part of the talk \, it is shown that an initial-value problem for local solutions of th e Semiclassical Einstein Equations can be formulated in cosmological s pacetimes\, after fixing four initial data on the scale factor of the Universe. In the second part of the talk\, it is studied the problem o f stability of linearized solutions\, using a toy model which mimics t he semiclassical equations in cosmological spacetimes. In this case\, it is proved that\, if the quantum field driving the backreaction is m assive\, then there are choices of renormalization constants for which linear perturbations with compact spatial support decay for large tim es\, thus indicating stability of the underlying theory [arXiv:2007.14 665\, 2201.10288]. DTSTART:20230614T130000Z DTEND:20230614T150000Z LOCATION:Übung 3 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik: Valter Moretti (Trento): On the Relat ivistic Spatial Localization for massive real scalar Klein-Gordon quan tum particles UID:ebafd1f0-67a1-4b18-a00e-b3a738909d4e DESCRIPTION:Valter Moretti (Trento) On the Relativistic Spatial Locali zation for massive real scalar Klein-Gordon quantum particles Abstract : I will present some recent achievements about the long-standing issu e of relativistic spatial localization of a quantum (massive scalar) p article. I will focus in particular on problems related to local causa lity. A new notion of POVM localization due to D.Terno will be discuss ed by pointing out some new physically meaningful features of it\, foc ussing onthe interplay with the Newton-Wigner localization\, the Heger feldt theorem and the causal localization rquirement introduced by D.P .L. Castrigiano. Talk Based on arXiv:2304.02133 (Lett. Math. Phys. 202 3 in print). DTSTART:20230615T141500Z DTEND:20230615T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik: Evgeny Korotyaev (Changchun\, China): Inverse resonance scattering on rotationally symmetric manifolds UID:ea728caf-6d56-4065-bf8b-085b4e4ea11a DESCRIPTION:Evgeny Korotyaev (Changchun\, China) Inverse resonance sca ttering on rotationally symmetric manifolds Evgeny Korotyaev jointly w ith Hiroshi Isozaki Academy for Advance interdisciplinary Studies\, No rtheast Normal University Changchun\, China Abstract: We discuss inver se resonance scattering for the Laplacian on a rotationally symmetric manifold M = (0\,infty) x Y whose rotation radius is constant outside some compact interval. Here Y is a compact m-dimensional Riemannian ma nifold. The Laplacian on M is unitarily equivalent to a direct sum of one-dimensional Schrodinger operators with compactly supported potenti als on the half-line. We prove 1) Asymptotics of counting function of resonances at large radius. 2) The rotation radius is uniquely determi ned by its eigenvalues and resonances. 3) There exists an algorithm to recover the rotation radius from its eigenvalues and resonances. The proof is based on some non-linear real analytic isomorphism between tw o Hilbert spaces. DTSTART:20230621T141500Z DTEND:20230621T160000Z LOCATION:Seminarraum / 04.363-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik: Danilo José Polo Ojito (Chile): Inte rface currents and corner states in magnetic quarter-plane systems UID:74896dca-fc13-44d0-b620-aec7dfe323e1 DESCRIPTION:Danilo José Polo Ojito Interface currents and corner stat es in magnetic quarter-plane systems Abstract:The purpose of this talk is to study the propagation of currents along the interface of two 2- d magnetic systems\, where one of them occupies the first quadrant of the plane. By considering the tight-binding approximation model and K- theory\, we prove that\, for an integer number that is given by the di fference of two bulk topological invariants of each individual system\ , such interface currents are quantized. We further state the necessar y conditions to produce corner states for these kinds of underlying sy stems\, and we show that they have topologically protected asymptotic invariants. DTSTART:20230629T141500Z DTEND:20230629T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik: Lars Koekenbier (FAU): Spectral local izer for line-gapped non-hermitian systems UID:196b5fe1-f26d-4c3d-a738-07e8cc9357e2 DESCRIPTION:Lars Koekenbier (FAU) Spectral localizer for line-gapped n on-hermitian systems Abstract: Short-ranged and line-gapped non-hermit ian Hamiltonians have strong topological invariants given by an index of an associated Fredholm operator. It is shown how these invariants c an be accessed via the signature of a suitable spectral localizer. Thi s numerical technique is implemented in an example with relevance to t he design of topological photonic systems\, such as topological lasers . DTSTART:20230706T141500Z DTEND:20230706T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Daniel Burgarth (FAU): Bounds for th e Jaynes-Cummings Hamiltonian UID:0cb1fe98-9619-4b03-b64b-65c17fba994f DESCRIPTION:Daniel Burgarth (FAU) Bounds for the Jaynes-Cummings Hamil tonian Abstract: The Jaynes-Cummings Hamiltonian is one of the most co mmonly used model for the interaction of light and matter. It arrises through a more fundamental model by an approximation known as the rota ting wave approximation (RWA). Although commonly used in physics\, the approximation error is hard to control due to the unboundedness of th e operators involved. Even in finite dimensional systems such bounds a re often only perturbative. I will demonstrate a simple yet very power ful way to find bounds for the Jaynes-Cummings Hamiltonian and related models. PS: This will be a blackboard talk –\; feel free to ask me anything and I’\;ll be happy to go off on tangents instead. Th e real purpose of this talk is to find common ground for potential col laborations between mathematics and physics at Erlangen DTSTART:20230511T141500Z DTEND:20230511T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik: Jan Mandrysch (Leipzig): Energy inequ alities in integrable quantum field theories UID:81c91126-51b8-4484-969c-c9d9406c1a05 DESCRIPTION:Jan Mandrysch (Leipzig) Energy inequalities in integrable quantum field theories Abstract: Many results in general relativity re ly crucially on classical energy conditions inflicted on the stress-en ergy tensor. Quantum matter\, however\, violates these conditions sinc e the energy density can fluctuate and in particular become arbitraril y negative at a point. Nonetheless quantum matter should have some rem iniscent notion of stability\, which can be captured by so-called quan tum (weak) energy inequalities (QEIs). These are lower bounds of the s meared quantum-stress-energy tensor and could be proven in many types of free quantum field theories on both flat and curved spacetimes. In models with self-interaction though only few results exist. We are her e presenting results in a wide class of integrable QFT models in 1+1d including for instance the O(N)-nonlinear-sigma model. A preprint is a vailable under https://arxiv.org/abs/2302.00063 DTSTART:20230525T141500Z DTEND:20230525T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik: Ian Koot (FAU): Relative Entropy and the (Quantum) Method of Types UID:a13b76a6-4525-42ef-88c6-b8138264c11b DESCRIPTION:Ian Koot (FAU) Relative Entropy and the (Quantum) Method o f Types Abstract: The Method of Types is a set of results in probabili ty theory and information theory that connect (relative) entropy to th e probabilities of outcomes in repeated measurement. There does not se em to exist a noncommutative generalization of the Method of Types\, e ven though some results and concepts have noncommutative versions. We give an overview of the Method of Types\, emphasizing the role that (r elative) entropy plays in it\, and discuss possibilities and obstacles in trying to generalize the method to the noncommutative setting. The aim is to get a better understanding of (relative) entropy\, in the c ommutative setting but especially in the noncommutative setting. DTSTART:20230601T141500Z DTEND:20230601T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Christoph Setescak (Regensburg): Dis ordered Topological Insulators: From Experiment to K-theory UID:a063b9b2-4a1d-4fec-b58f-c79dd7a81ca9 DESCRIPTION:Christoph Setescak (Regensburg) Disordered Topological Ins ulators: From Experiment to K-theory Abstract: Topological Insulators are semiconductors that exhibit a topological non-triviality in their mathematical description\, leading to the emergence of a gap-closing s urface state at their boundary with certain highly sought-after proper ties. Roe C*-algebras provide a mathematical framework to describe top ological insulators in the presence of disorder\, whereby the topologi cal phase corresponds to a non-trivial class in K-theory. It will be i llustrated how atomically resolved experimental data can be reproduced within this framework. Moreover\, these invariants can be calculated numerically via the index of a Fredholm operator. For the two-dimensio nal Kane-Mele model we were able to reproduce the phase diagram previo usly reported in the literature\, but in the case of the three-dimensi onal topological insulator Bi2Se3\, no result recreating previous work was obtained. DTSTART:20230202T151500Z DTEND:20230202T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Christian Jäkel (Sao Paulo): Modula r Hamiltonians on the de Sitter Space UID:b2ced65d-71e8-4f19-8b8a-005a202c2a9d DESCRIPTION:Christian Jäkel (Sao Paulo) Modular Hamiltonians on the d e Sitter Space Abstract: While the main aim of this work is to contrib ute to the ongoing investigation of modular Hamiltonians\, this work i s also a case study. It aims to illustrate how to decipher the laws of nature and cast them in a mathematical language. Once the tools of To mita-Takesaki modular theory are added to Wigner’\;s group theore tic approach\, the far-reaching and unexpected consequences of the sel ection of a highly symmetric space-time\, like de Sitter space\, gain visibility. DTSTART:20230209T151500Z DTEND:20230209T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Prof. Kang Li (FAU): An introduction to AF algebras UID:ebcf4708-bcb8-48e6-8de0-1a219f3aebd4 DESCRIPTION:Prof. Kang Li (FAU) An introduction to AF algebras Abstrac t: In this talk\, I will discuss the basic properties of AF algebras a nd introduce AF-embeddability problem. DTSTART:20230420T141500Z DTEND:20230420T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Joris De Moor (FAU): Footprint of a topological phase transition on the density of states UID:c7465326-8694-4f3a-a78d-ae85194c383a DESCRIPTION:Joris De Moor (FAU) Footprint of a topological phase trans ition on the density of states Abstract: For a one-dimensional random discrete Schrödinger operator\, the energies at which all transfer ma trices commute and have their spectrum off the unit circle are called critical hyperbolic. Disorder driven topological phase transitions in such models are characterized by a vanishing Lyapunov exponent at the critical energy. It is shown that the density of states away from a tr ansition has a pseudogap with an explicitly computable Hölder exponen t\, while it has a logarithmic divergence (Dyson spike) at the transit ion points. The proof is based on renewal theory for the Prüfer phase dynamics and the optional stopping theorem for martingales of suitabl y constructed comparison processes. DTSTART:20230504T141500Z DTEND:20230504T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Claus Köstler (Cork): Distributiona l symmetries and invariance principles in noncommutative probability UID:a982b310-adbe-ef47-aac9-c42acae6a117 DESCRIPTION:Claus Köstler (Cork) Distributional symmetries and invari ance principles in noncommutative probability Abstract: Distributional symmetries and invariance principles provide deep structural results in classical probability. For example\, the de Finetti theorem charact erizes an infinite sequence of random variables to be conditional inde pendent and identically distributed if and only if its joint distribut ion is invariant under permuting these random variables. Recently sign ificant progress was made in transferring such de Finetti type results to an operator algebraic setting of noncommutative probability. My ta lk will introduce to and overview some of these newer developments. Se lected References: [1] Köstler\, Claus. A noncommutative extended de Finetti theorem. J. Funct. Anal. 258 (2010)\, no. 4\, 1073-1120. [2] G ohm\, Rolf\; Köstler\, Claus. Noncommutative independence from the br aid group B∞. Comm. Math. Phys. 289 (2009)\, no. 2\, 435-482. [3] K östler\, Claus\; Speicher\, Roland. A noncommutative de Finetti theor em: invariance under quantum permutations is equivalent to freeness wi th amalgamation. Comm. Math. Phys. 291 (2009)\, no. 2\, 473-490. [4] D ykema\, Kenneth J.\; Köstler\, Claus\; Williams\, John D. Quantum sym metric states on free product C∗-algebras. Trans. Amer. Math. Soc. 3 69 (2017)\, no. 1\, 645-679. [5] Evans\, D. Gwion\; Gohm\, Rolf\; Kös tler\, Claus. Semi-cosimplicial objects and spreadability. Rocky Mount ain J. Math. 47 (2017)\, no. 6\, 1839-1873. [6] Köstler\, Claus\; Kri shnan\, Arundhathi\; Wills\, Stephen J. Markovianity and the Thompson Monoid F+. ePrint arXiv:2009.14811\, to appear in J. Funct. Anal. [7] Köstler\, Claus\; Krishnan\, Arundhathi. Markovianity and the Thompso n Group F. SIGMA Symmetry Integrability Geom. Methods Appl. 18 (2022)\ , Paper No. 083. DTSTART:20230112T151500Z DTEND:20230112T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Onirban Islam (Potsdam): Feynman pro pagators on curved spacetimes UID:18e1e769-710e-44d2-bac4-b657010e2090 DESCRIPTION:Onirban Islam (Potsdam) Feynman propagators on curved spac etimes Abstract: It is a classic result that any wave operator on a gl obally hyperbolic spacetime admits unique advanced and retarded propag ators. With the advent of quantum field theory\, a new type of propaga tor emerges–\;the Feynman propagator. These propagators are an es sential ingredient of quantum field theory and are intimately connecte d with quantum states. Moreover\, they arise naturally in global and s pectral analyses on Lorentzian manifolds. In contrast to the advanced and retarded propagators\, Feynman propagators are not unique unless t he spacetime admits time-translation symmetry. In this talk\, I shall present a construction of Feynman propagators satisfying a positivity property based on the idea of microlocalisation which\, in a sense\, i s a tool to connect a first-order pseudodifferential operator to the p artial derivative. This\, in turn\, provides a new construction of Had amard states. I shall first introduce the required notions from microl ocal analysis and then explain microlocalisation in a geometric fashio n. (Joint work with Alexander Strohmaier based on arXiv:2012.09767 [ma th.AP]) DTSTART:20230119T151500Z DTEND:20230119T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Yoh Tanimoto (Rom): Unitary vertex a lgebras and Wightman conformal field theories UID:7e9b4950-0c3b-42db-8875-e78de245c2de DESCRIPTION:Yoh Tanimoto (Rom) Unitary vertex algebras and Wightman co nformal field theories Abstract: We report recent progress on the axio matic approaches to two-dimensional conformal field theory. We prove t he equivalence between unitary vertex operator algebras and Moebius-co variant Wightman fields with some analytic conditions. We will discuss possible generalizations to full 2d CFT. DTSTART:20230126T151500Z DTEND:20230126T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Ko Sanders (FAU): Quantum energy ine qualities and their applications UID:85828a12-27f0-8c42-b904-0eecec340c8b DESCRIPTION:Ko Sanders (FAU) Quantum energy inequalities and their app lications Abstract: Quantum energy inequalities can be used to express the stability of a quantum field theory in analogy to the classical e nergy conditions in GR. In particular\, they are expected to be a suit able assumption to prove quantum analogs of e.g. the classical singula rity theorems of Penrose and Hawking\, where energy conditions played a key role. After a brief general review of these quantum energy inequ alities\, I will argue that they also have another important applicati on: they can be used to control the high energy behaviour of quantum f ields. This is in analogy to Hamiltonian bounds for quantum fields in Minkowski space\, replacing the Hamiltonian operator by an averaged en ergy density. This potentially opens up the way to manipulate pointwis e quantum fields and operator product expansions in a rigorous way\, a lso for quantum fields in curved spacetimes\, where in general no Hami ltonian operator is available. DTSTART:20221020T141500Z DTEND:20221020T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Karl-Henning Rehren (Göttingen): St ring-localized QFT in action: Application to the Abelian Higgs model UID:ac4383de-7c43-471c-802b-11cedffddb57 DESCRIPTION:Karl-Henning Rehren String-localized QFT in action: Applic ation to the Abelian Higgs model Abstract: String-localized QFT improv es perturbation theory with massive vector bosons. It keeps the pertur bation theory renormalizable without introducing indefinite metric and ghosts. The ensuing string-dependence can be systematically eliminate d in terms of higher-order corrections. The latter serve as physical p redictions. A prototype is the Abelian Higgs model: Interactions of a massive vector field can be renormalized without spontaneous symmetry breaking. But it must couple to a scalar field with a double-well pote ntial self-coupling. A benefit compared to the standard BRST method is that off-shell interacting charged fields can be constructed on the H ilbert space. Joint work with Jens Mund and Bert Schroer (arXiv:2209.0 6133) DTSTART:20221117T151500Z DTEND:20221117T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Pieter Naaijkens: Classification of topologically ordered phases of matter in 2D UID:b9ec7dab-e247-4f41-a005-a36b8275d73f DESCRIPTION:Pieter Naaijkens Classification of topologically ordered p hases of matter in 2D Abstract: In this talk I will consider topologic al phases of matter which have what is called long range entanglement (LRE). Ground states with LRE in a non-trivial phase cannot be convert ed into a product state using only (sufficiently) local operations. An interesting aspect is that such states can support quaisparticles wit h braided statistics\, called anyons. I will compare different approac hes to extracting the algebraic properties of these anyons from first principles\, and explain how this relates to the classification of top ologically ordered phases. I will then highlight some recent developme nts and current challenges in the field. DTSTART:20221124T151500Z DTEND:20221124T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Ivan Romualdo de Oliveira (Sao Paulo ): Localizability of Quantum Mechanical Systems on Curved Spacetimes UID:7edbc9ee-3e96-43fa-bc8c-ef4c3ec865af DESCRIPTION:Ivan Romualdo de Oliveira Localizability of Quantum Mechan ical Systems on Curved Spacetimes Abstract: DTSTART:20221201T151500Z DTEND:20221201T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Mathematical Physics Colloquium Rege nsburg-Erlangen\, Claudio Dappiaggi (Pavia): Stochastic Partial Differ ential Equations and Renormalization à la Epstein-Glaser UID:d3033ff0-0cba-44bf-ad7d-20ff17e7b83b DESCRIPTION:Claudio Dappiaggi Stochastic Partial Differential Equation s and Renormalization à la Epstein-Glaser Abstract: We present a nove l framework for the study of a large class of non-linear stochastic pa rtial differential equations\, which is inspired by the algebraic appr oach to quantum field theory. The main merit is that\, by realizing ra ndom fields within a suitable algebra of functional-valued distributio ns\, we are able to use specific techniques proper of microlocal analy sis. These allow us to deal with renormalization using an Epstein-Glas er perspective\, hence without resorting to any specific regularizatio n scheme. As a concrete example we shall use this method to discuss bo th the stochastic $Phi^3_d$ model and the non-linear Schroedinger equa tion. Talk based on [1] C.D.\, Nicolò Drago\, Paolo Rinaldi & Lorenzo Zambotti\, Commun. Contemp. Math. 24 (2022)\, no. 7\, Paper No. 21500 75\, [2] Alberto Bonicelli\, C.D. & Paolo Rinaldi\, https://arxiv.org/ pdf/2111.06320 DTSTART:20221208T073000Z DTEND:20221208T091500Z LOCATION:via zoom DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Patricia Ribes Metidieri (Nijmegen): Entanglement: ubiquitous\, but measurable? UID:d929d49c-bac9-4134-ae7c-ebb208ae6a4d DESCRIPTION:Patricia Ribes Metidieri (Nijmegen) Entanglement: ubiquito us\, but measurable? Abstract: It is well known that entanglement is u biquitous in quantum field theory: even the simplest states within the simplest field theories are highly entangled. The foundation of this statement rests on two results: (1) the Reeh-Schlieder theorem\, which shows that all field variables in any one region of spacetime are ent angled with variables in other regions\, and (2) the calculations of e ntanglement entropy between a region and its complement\, which show t hat entanglement between adjoining spacetime regions is not just large but UV divergent. In this talk\, I will argue that these results do n ot provide much information about the entanglement between individual local degrees of freedom. I will then present a way of quantifying suc h entanglement\, involving only a finite number of degrees of freedom\ , finite regions of space\, and quantities that are directly measurabl e. I will summarize our understanding both in (1+D)-dimensional Minkow ski spacetime and de Sitter spacetime\, paying special attention to th e consequences of the latter in our ability to detect quantum effects from the inflationary era. DTSTART:20221215T151500Z DTEND:20221215T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:Workshop LQP46 UID:4bafa415-7409-4b6c-b0e1-59178f4bb7ee DESCRIPTION:Workshop LQP46 Weitere Infos auf: Workshop LQP46 (2022) DTSTART:20220624T120000Z DTEND:20220625T140000Z LOCATION:tba DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Roberto Conti (Rom): Automorphisms o f the Cuntz algebras and their Weyl groups. A case study. UID:9f43b65c-7661-9449-8d7e-a74f2090edb2 DESCRIPTION:Roberto Conti (Rom) Automorphisms of the Cuntz algebras an d their Weyl groups. A case study. Abstract: Multiplets of isometries with orthogonal ranges summing up to 1 were systematically used by Dop licher and Roberts in the early 70’\;s in their study of the supe rselection structure of Quantum Field Theory. Nowadays\, the C*-algebr a generated by any such multiplet is known as Cuntz algebra O_n\, wher e n is the cardinality of the given multiplet. Since their introductio n\, Cuntz algebras have been the subject of endless investigations\, f rom many different points of view. They are probably the most studied class of C*-algebras ever. Notably\, the study of their automorphisms reveals many challenging facets\, where operator algebras meet Lie the ory\, dynamical systems and combinatorics. We will present an overview of recent results\, along with some open questions. DTSTART:20220630T141500Z DTEND:20220630T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Dr. Simon Wood (Cardiff\, Hamburg): Lie theory beyond category O in conformal field theory and vertex\,ope rator algebras UID:2e1bc934-38de-45d1-9a6a-b7f2493f9cea DESCRIPTION:Dr. Simon Wood Lie theory beyond category O in conformal f ield theory and vertex operator algebras Abstract: Affine Lie algebras provide the means for constructing some of the best understood confor mal field theories or vertex operator algebras. If the level of the af fine Lie algebra is non-negative integral\, then the integrable module s form a modular tensor category (among many other properties\, this i mplies an action of the modular group on characters). In this talk I w ill give an overview of why this is highly desirable from the perspect ive of conformal field theory and some new results on modular properti es and their consequences at certain non-integral levels\, called admi ssible levels. No prior knowledge of vertex operator algebras or confo rmal field theory will be assumed. I will do my best to motivate every thing through Lie theory. DTSTART:20220704T141500Z DTEND:20220704T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Nora Doll (FAU): tba UID:0795034c-28a4-495e-8cba-0c193e447635 DESCRIPTION:Nora Doll (FAU) Abstract: DTSTART:20220707T141500Z DTEND:20220707T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Prof. Alexander Bedikov (Breslau): H ierarchical Schrödinger-type operators: the case of potentials with\, local singularities UID:ca54303d-3e54-4a84-95c9-ede6eaabf463 DESCRIPTION:Prof. Alexander Bendikov (Breslau) Hierarchical Schröding er-type operators: the case of potentials with local singularities Abs tract: The goal of this work (joint with A. Grigoryan and S. Molchanov ) is twofold. We prove that the operator H=L+V \, the perturbation of the Taibleson-Vladimirov multiplier L=D^{α} by the potential V(x)=b ‖x‖^{-α}\, b≥b_{∗}\, is essentially self-adjoint and non-nega tive definite (the critical value b_{∗} depends on α and will be sp ecified in the paper). While the operator H is non-negative definite t he potential V(x) may well take negative values\, e.g. b_{∗} DTSTART:20220728T141500Z DTEND:20220728T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Richard Montgomery (Santa Cruz): Sca ttering and Compactifying in Newton's three body problem UID:e3454e05-300c-493d-a13f-6d170993e570 DESCRIPTION:Richard Montgomery (Santa Cruz) Scattering and Compactifyi ng in Newton’\;s three body problem Abstract: One approach to sca ttering theory is to add a manifold at inifinty as a place for things „\;to go to“\; as they leave the manifold. These things can be classical trajectories or waves (a la the Melrose school). I will o utline the approach\, state a theorem and a few open problems. DTSTART:20221013T141500Z DTEND:20221013T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Prof. Felix Finster (Regensburg): An introduction to causal fermion systems and the causal action principl e UID:f6eef7ed-65b6-4bb1-b998-c3f4327c44eb DESCRIPTION:Prof. Felix Finster (Regensburg) An introduction to causal fermion systems and the causal action principle Abstract: The theory of causal fermion systems is an approach to describe fundamental physi cs. It gives quantum mechanics\, general relativity and quantum field theory as limiting cases and is therefore a candidate for a unified ph ysical theory. Moreover\, causal fermion systems provide a general fra mework for modelling and analyzing non-smooth spacetime structures. Th e dynamics of a causal fermion system is described by a nonlinear vari ational principle\, the causal action principle. The aim of the talk i s to give a simple introduction. I will proceed chronologically and ex plain step by step how the underlying concepts and objects evolved fro m 1990 to today. This will lead us to the abstract definitions. The un derlying physical principles will be discussed. At the end of the talk \, I will briefly outline how to get the connection to a quantum state in the algebraic formulation. DTSTART:20220127T151500Z DTEND:20220127T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Manuel Quaschner (FAU): Noncollision singularities with external forces UID:5c127f72-3832-7841-8dfb-efc6454f217e DESCRIPTION:Manuel Quaschner (FAU) Noncollision singularities with ext ernal forces Abstract: The existence of noncollision singularities in the $n$-body problem was already conjectured by Painlevé in 1895. Eve n before the existence was proven in the 1990s\, the question came up\ , whether the set of all initial conditions leading to noncollision si ngularities is a set of measure 0. A first result of this kind was pro ven for $n=4$ particles in $dgeq 2$ dimensions by Saari (1977). Using the so called Poincaré surface method\, Fleischer (2018) could improv e this for $n=4$ particles in $d geq 2$ dimensions by extending the re sult to a wider class of potentials. But the problem is still open for more than four particles. After an overview of these works\, we add s ome sufficiently small external forces to the well understood case of $n=4$ particles. In order to apply the Poincaré surface method\, we n eed to prove good estimates on the shape of the orbits\, which are clo se to the movement on a straight line. In the end we will show how one could use this results to prove the improbability of larger systems t hat can be suitably decomposed into diverging systems of up to four pa rticles each. DTSTART:20220210T151500Z DTEND:20220210T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Prof. Rainer Verch (Leipzig): Temper ature and entropy-area relation of quantum matter near spherically sym metric outer trapping horizons UID:3f8c2d47-0507-4352-b816-41b71381b109 DESCRIPTION:Prof. Rainer Verch (Leipzig) Temperature and entropy-area relation of quantum matter near spherically symmetric outer trapping h orizons Abstract: We consider spherically symmetric spacetimes with an outer trapping horizon. Such spacetimes are generalizations of spheri cally symmetric black hole spacetimes where the central mass can vary with time\, like in black hole collapse or black hole evaporation. The se spacetimes possess in general no timelike Killing vector field\, bu t admit a Kodama vector field which provides a replacement. Sphericall y symmetric spacelike cross-sections of the outer trapping horizon def ine in- and outgoing lightlike congruences. We investigate a scaling l imit of Hadamard 2-point functions of a quantum field on the spacetime onto the ingoing lightlike congruence. The scaling limit 2-point func tion has a universal form and a thermal spectrum with respect to the t ime-parameter of the Kodama flow\, where the inverse temperature is re lated to the surface gravity of the horizon cross-section in the same way as in the Hawking effect for an asymptotically static black hole. Similarly\, the tunneling probability in the scaling limit between in- and outgoing Fourier modes with respect to the the Kodama time shows a thermal distribution with the same inverse temperature\, determined by the surface gravity. This can be seen as a local counterpart of the Hawking effect for a dynamical horizon in the scaling limit. The scal ing limit 2-point function as well as the 2-point functions of coheren t states of the scaling-limit-theory have relative entropies behaving proportional to the cross-sectional horizon area. Thereby\, we establi sh a local counterpart\, and microscopic interpretation in the setting of quantum field theory on curved spacetimes\, of the dynamical laws of outer trapping horizons\, derived by Hayward and others in generali zing the laws of black hole dynamics originally shown for stationary b lack holes by Bardeen\, Carter and Hawking. (Joint w DTSTART:20220519T141500Z DTEND:20220519T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Dr. Alexander Stottmeister (Hannover ): Anyon braiding and renormalization UID:c3404162-364d-4cfe-bcd1-3abbcfab7992 DESCRIPTION:Dr. Alexander Stottmeister (Hannover) Anyon braiding and r enormalization Abstract: A braiding operation defines a real-space ren ormalization group for anyonic chains. The resulting renormalization g roup flow can be used to define a quantum scaling limit by operator-al gebraic renormalization. I will illustrate how this works for the Isin g chain\, also known as transverse-field Ising model. In this case\, t he quantum scaling limit results in the vacuum state of the well-known Ising CFT. Distinguishing between the braiding and its inverse is dir ectly related to the chiral sectors of the Ising CFT. DTSTART:20220602T141500Z DTEND:20220602T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Joris De Moor (FAU): Partially hyper bolic random dynamics on Grassmannians UID:282641af-eb98-4f7b-b831-a924f1871ca2 DESCRIPTION:Joris De Moor Partially hyperbolic random dynamics on Gras smannians Abstract: A sequence of invertible matrices given by a small random perturbation around a fixed diagonal partially hyperbolic matr ix induces a random dynamics on the Grassmann manifolds. Under suitabl e weak conditions it is known to have a unique invariant (Furstenberg) measure. The main result gives concentration bounds on this measure s howing that on average the random dynamics stays in the vicinity of st able fixed points of the unperturbed matrix\, in a regime where the st rength of the random perturbation dominates the local hyperbolicity of the diagonal matrix. As an application\, bounds on sums of Lyapunov e xponents are obtained. DTSTART:20220609T141500Z DTEND:20220609T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Stefan Waldmann (Würzburg): Converg ence of star products UID:3575ad0f-d540-e048-845d-e3ed89033e17 DESCRIPTION:Stefan Waldmann (Würzburg) Convergence of star products A bstract: In my talks I will report on recent progress in the understan ding of the convergence problem in formal deformation quantization. Wh ile the existence and classification of formal star products is well-u nderstood in the general case of Poisson manifolds\, the questions whe ther such formal star products have reasonable convergence properties\ , as required by physical applications\, is wide open. I will give sev eral classes of examples where the situation can be analyzed explicitl y. DTSTART:20211118T151500Z DTEND:20211118T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Dr. Konstantin Merz (Braunschweig): Eigenvalue estimates for Schrödinger operators using Fourier analysis UID:83f3457c-aee8-489b-8364-8091aca953dd DESCRIPTION:Dr. Konstantin Merz (Braunschweig) Eigenvalue estimates fo r Schrödinger operators using Fourier analysis Abstract: Estimating t he location and accumulation rate of eigenvalues of Schrödinger opera tors is a classic problem in spectral theory and mathematical physics. For short-range potentials these problems can often be effectively tr eated using Fourier analytic methods like the Tomas-Stein restriction theorem. As an example we derive eigenvalue asymptotics for Schröding er-type operators whose kinetic energy vanishes on a codimension one s ubmanifold. Time permitting\, we discuss another example: locating eig envalues of ordinary Schrödinger operators with randomized\, long-ran ge\, complex-valued potentials using a randomized version of the Tomas -Stein theorem by Bourgain. The talk is based on joint work with Jean- Claude Cuenin. DTSTART:20211125T151500Z DTEND:20211125T170000Z LOCATION:Übung 1 / 01.250-128\, Cauerstr. 11\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Johannes Kellendonk (Lyon I): Ellis semigroup in symbolic dynamics UID:d1a4e45f-0197-2b4b-a078-3af296f797a8 DESCRIPTION:Johannes Kellendonk (Lyon I) Ellis semigroup in symbolic d ynamics Abstract: Given a group G of homeomorphisms of a compact space X\, the Ellis semigroup of G is the closure of G in the topology of p oint wise convergence. Its topological and algebraic properties charac terise the G action on X. This semigroup has been introduced by Robert Ellis in the 60’\;s. We will provide a short overview of this th eory and present some recent results which arise in the context of sym bolic dynamics\, that is\, for G = Z and X a space of symbolic sequenc es. DTSTART:20211202T151500Z DTEND:20211202T170000Z LOCATION:zoom DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Marcello Seri (Groningen): Contact m echanics and numerical integration UID:f2435641-0916-b441-aed6-9bbff8a3787a DESCRIPTION:Marcello Seri (Groningen) Contact mechanics and numerical integration Abstract: It is well known that an analogue to Hamiltonian systems can be defined on contact manifolds\, the odd dimensional cou sins to the even symplectic manifold. Their odd dimensionality introdu ces an extra freedom that allows the energy to vary and which is not n ecessarily restricted to a time-dependence. In the talk\, we will pres ent some geometric integrators for contact Hamiltonian systems\, numer ical schemes that guarantee the the preservation of the contact geomet ric structure. The derivation of the numerical integrators will be use d as way to review some of the most relevant properties of contact Ham iltonian systems and to provide some intriguing examples that motivate d the recent surge of interest in their analytical and numerical study . DTSTART:20211209T154500Z DTEND:20211209T180000Z LOCATION:zoom-Vortrag DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Ian Koot (FAU): The propagation numb er of operator systems UID:b9c6501b-cf82-1648-aab8-f9c2e1364275 DESCRIPTION:Ian Koot (FAU) The propagation number of operator systems Abstract: It is well known that every C*-algebra is isomorphic to a no rm-closed\, self-adjoint subalgebra of the bounded operators on some H ilbert space. We can generalize this to norm-closed\, self-adjoint sub spaces of bounded operators\; these structures are called operator sys tems. The spectral triple-formulation of Noncommutative Geometry is ba sed on C*-algebras\, and in their recent efforts to generalize this to operator systems\, Connes and Van Suijlekom defined a property of ope rator systems which they called the propagation number. We invastigate the behaviour of the propagation number under the minimal tensor prod uct of operator systems\, where an exact expression for the propagatio n number of the tensor product in terms of the propagation number of i ts factors can be found. We also discuss the possibility of an express ion for the propagtion number of the dual operator system. DTSTART:20220120T151500Z DTEND:20220120T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Tom Stoiber (Erlangen): Callias-type operators associated to spectral triples UID:3398fa44-b4fe-a641-83f7-292e00e45a2e DESCRIPTION:Tom Stoiber Callias-type operators associated to spectral triples Abstract: Callias-type (or Dirac-Schroedinger) operators assoc iated to abstract semifinite spectral triples are introduced and their indices are computed in terms of an associated index pairing derived from the spectral triple. The result is then interpreted as an index t heorem for a non-commutative analogue of spectral flow. Both even and odd spectral triples are considered\, and both commutative and non-com mutative examples are given. DTSTART:20211028T141500Z DTEND:20211028T160000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Maximilian Duell (LMU München): N-P article Scattering in Wedge-local Quantum Field Theories UID:4770d50d-da47-0346-93de-4e3e144e4761 DESCRIPTION:Maximilian Duell (LMU München) N-Particle Scattering in W edge-local Quantum Field Theories Abstract: Wedge-local quantum field theories (wQFT) are a generalization of relativistic local QFTs\, in w hich observables can be localized in very large wedge-shaped regions i n space-time. It is long known that the wedge-local perspective someti mes has theoretical advantages. Only more recently\, (w)QFT models des cribing non-trivial scattering reactions have been constructed directl y in a wedge-local framework by Lechner\, Buchholz\, Summers\, and oth ers. Such constructions have provided non-trivial models also on four- dimensional Minkowski space-time\, whereas the corresponding construct ion problem for interacting local QFT is still open. On the other hand \, Scattering theory in a wedge-local setting was previously only deve loped up to the two-particle level and a generalization to higher part icle numbers was not expected for geometric reasons. In my talk I will explain how to construct N-particle scattering states for massive par ticle in wedge-local QFTs. Based on this construction\, N-particle S-m atrices\, collision cross sections\, and other quantities of physical interest can be calculated directly in wQFTs. To conclude I will also discuss more recent work\, where this scattering theory is applied to wQFTs obtained by a general deformation construction of Buchholz\, Lec hner and Summers. (Based on my PhD thesis and joint work with W. Dybal ski) DTSTART:20211104T151500Z DTEND:20211104T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik\, Ricardo Correa da Silva (FAU): Modul ar Structures on a von Neumann Algebra on Hilbert-Schmidt Operators an d Applications to Thermodynamical Equilibrium States of Infinite Degen erated Systems UID:004ca9c6-c7f0-3f46-adb0-f2b932809d78 DESCRIPTION:Ricardo Correa da Silva (FAU) Modular Structures on a von Neumann Algebra on Hilbert-Schmidt Operators and Applications to Therm odynamical Equilibrium States of Infinite Degenerated Systems After an introduction to Tomita-Takesaki Modular Theory and KMS states\, we wi ll characterize all cyclic and separating vectors for a well-known von Neumann algebra acting on the Hilbert-Schmidt operators aiming to stu dy the thermal equilibrium states (KMS states) for this algebra. Then\ , we discuss the description of infinitely degenerate Hamiltonians in this algebra\, in particular\, the example of the Landau levels showin g that there is no cyclic and separating vector such that the modular Hamiltonian corresponds to the Landau Hamiltonian\, as argued in other work. Finally\, we try to reproduce the thermodynamical limit of the system confined in a finite box\, for physical reasons\, to better und erstand how the degeneracy grows as the box radius goes to infinity. DTSTART:20211111T151500Z DTEND:20211111T170000Z LOCATION:Übung 1 / 01.250-128\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik UID:a0496efd-3101-40ad-98fc-9a2792176f50 DESCRIPTION:Non-deterministic billiards Manuel Quaschner Abstract: In [Kn18]\, a simple non-deterministic model with three particles was int roduced in order to approximate the orbits of solutions of a Hamiltoni an equation with admissible potential and at most four bodies that do not have an asymptotic velocity. In these non-deterministic models\, n ear-collisions are substituted by collisions without conservation of k inetic energy. In order to approximate the orbits some properties of n on-deterministic models with three particles had to be derived such as the exponential growth (in the number of collisions) of the total kin etic energy and of the moment of inertia or a bound on the angular mom enta of each particle in terms of the total angular momentum. All thes e properties fail to hold in general\, if one considers non-determinis tic models with more than three particles. Our aim is to investigate t hese models and derive similar results to the results in the case of t hree particles. Therefor we have to define another number of collision s in which the growth of the above quantities is exponential by consid ering a reduced ordered systems of particles moving on a line. DTSTART:20200206T151500Z DTEND:20200206T170000Z LOCATION:U1\, Cauerstr. 11\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik UID:92e3c14f-78c5-4f5e-8c83-f5e95a320539 DESCRIPTION:THE NONCOMMUTATIVE GEOMETRY OF THE LANDAU HAMILTONIAN: MET RIC ASPECTS Maximiliano Sandoval\, Santiago\, Chile Abstract: This wor k provides a first step towards the construction of a noncommutative g eometry for the Quantum Hall Effect in the continuous. Taking inspirat ion from the ideas developed by Bellissard during the 80’\;s we b uild a spectral triple for the C*-algebra of continuous magnetic opera tors based on a Dirac operator with compact resolvent. The metric aspe cts of this spectral triple are studied\, and an important piece of Be llissard’\;s theory (the so-called first Connes‘\; formula) is proved. DTSTART:20201105T151500Z DTEND:20201105T170000Z LOCATION:online DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik UID:c622c474-0c3d-4c38-b4cd-f0d5bf559404 DESCRIPTION:Stability of a topological index under weak spin symmetry breaking Joris de Moor\, FAU DTSTART:20201112T151500Z DTEND:20201112T170000Z LOCATION:U1\, Cauerstr. 11\, Erlangen oder zoom DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik UID:2cd264b0-af57-434f-9825-2c663f814282 DESCRIPTION:Gap-filling via coarse geometry Matthias Ludewig\, Regensb urg Abstract: We explain a mathematical framework which uses methods f rom coarse geometry in order to model topological insulators. In this framework\, the boundary behavior is described in terms of exact seque nces in operator K-theory. In particular\, spectral gap-filling is imp lied by the non-triviality of a certain K-theoretic boundary map. As a n application\, this allows to show that the Landau Hamiltonian on a h yperbolic half-plane (and also on more general imperfect half-spaces) has no spectral gaps. DTSTART:20201119T151500Z DTEND:20201119T170000Z LOCATION:U1\, Cauerstr. 11\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik UID:312f539f-cfdc-49ef-98fb-b6510b541346 DESCRIPTION:Flat bands of edge states via weak invariants of semimetal s Hermann Schulz-Baldes (joint work with Tom Stoiber)\, FAU DTSTART:20201126T151500Z DTEND:20201126T170000Z LOCATION:U1\, Cauerstr. 11\, Erlangen oder zoom DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik UID:fb9dcc17-2b19-4b19-a489-3c6ecfb27038 DESCRIPTION:Mathematicians meet Fermi surfaces: a semiclassical approa ch to the dynamics of Bloch electrons Marcello Seri (Groningen) Abstra ct: The Fermi surface is an important concept in solid state physics a nd in the theory of transport of electron in metals. While physically this has Been thoroughly investigated in decades of experiments\, the mathematics has lagged behind. Only one class of examples has been tho roughly studied as part of a program started by Novikov and developed by his topological school. In this talk I will start from the physical definition of Fermi surface and a review of recent results by Novikov and Maltsev to justify the need for a new approach. I will then sugge st a rigorous definition of the physical Fermi surface in presence of perturbations in the semiclassical regime inspired by recent developme nt in the mathematics of topological insulators. The talk is based on a joint work with Max Lein and Giuseppe De Nittis. DTSTART:20201217T151500Z DTEND:20201217T170000Z LOCATION:online DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik UID:96eeff68-4500-254a-8cf3-205eaac99f00 DESCRIPTION:Koen van den Dungen The index of generalised Dirac-Schröd inger operators Abstract: We study the relation between spectral flow and index theory within the framework of (unbounded) KK-theory. In par ticular\, we consider a generalised notion of ‚\;Dirac-Schröding er operators‘\;\, consisting of a self-adjoint elliptic first-ord er differential operator D with a skew-adjoint ‚\;potential‘ \; given by a (suitable) family of unbounded operators on an auxiliary Hilbert module. We show that such Dirac-Schrödinger operators are Fr edholm\, and we prove a relative index theorem for these operators (wh ich allows cutting and pasting of the underlying manifolds). Furthermo re\, we show that the index of a Dirac-Schrödinger operator represent s the pairing (Kasparov product) of the K-theory class of the potentia l with the K-homology class of D. We prove this result without assumin g that the potential is differentiable\; instead\, we assume that the ‚\;variation‘\; of the potential is sufficiently small near infinity. In the special case of the real line\, we recover the well-k nown equality of the index with the spectral flow of the potential. DTSTART:20210114T151500Z DTEND:20210114T170000Z LOCATION:online DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik UID:1e3878e6-0b60-457d-bd10-56699347e4a5 DESCRIPTION:Florian Dorsch Pseudo-gaps for random hopping models arXiv -Artikel DTSTART:20191128T151500Z DTEND:20191128T161500Z LOCATION:Übung 1 / 01.250-128\, Cauerstr. 11\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik UID:b043767e-3573-4327-b6fd-791f9ebca4a1 DESCRIPTION:Lei Zhao (Augsburg) J^+-Invariants for two-center Stark-Ze eman systems Abstract: For immersed curves in the plane\, Arnold has d efined three invariants in which the J^+-invariant has been adapted by Cieliebak-Frauenfelder-van Koert in 2017 to two invariants for period ic orbits of (one-center) Stark-Zeeman systems which includes the two- center problem and the restricted three-body problem as examples. Thes e invariants are invariant under homotopy along generic family of peri odic orbits of Stark-Zeeman systems. In this talk I will recall their construction\, as well as explain an extension\, jointly with K. Cieli ebak and U. Frauenfelder\, for Stark-Zeeman systems with two Newtonian /Coulombian singularities\, in which case we obtain four J^+-like inva riants\, based on Levi-Civita and Birkhoff regularizations. DTSTART:20191205T151500Z DTEND:20191205T170000Z LOCATION:Übung 1 / 01.250-128\, Cauerstr. 11\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik UID:c1f90dc1-c365-4899-884d-75c970e004bd DESCRIPTION:Amanda Young (TUM) On the Stability of Gapped Ground State Phases of Frustration-Free Quantum Spin Systems Abstract: Gapped quan tum spin systems with topologically ordered ground states have been of interest due to their potential for developing fault-tolerant quantum codes. A key feature of such models is that the spectral gap remains open in the presence of small\, local perturbations. In [1-3]\, a new approach utilizing Hasting’\;s quasi-adiabatic continuation prove d spectral gap stability for frustration-free quantum spin models with periodic boundary conditions and ground states that satisfy a finite- volume topological order condition. Imperative to these results is tha t the quasi-adiabatic continuation (also known as the spectral flow) s atisfies a Lieb-Robinson type locality estimate. In this talk\, we fir st review quasi-locality estimates for quantum lattice systems with sp ecific focus on the quasi-adiabatic continuation. We then discuss how to generalize the stability result from [3] in several directions: inc luding to quantum spin systems with more general boundary conditions\, quantum spin systems with discrete symmetry breaking\, and (time perm itting) lattice fermion models. This talk is based on joint work with Bruno Nachtergaele and Robert Sims. [1] S. Bravyi\, M. Hastings and S. Michalakis\, Topological quantum order: stability under local perturb ations\, J. Math. Phys. 51 093512 (2010) [2] S. Bravyi and M. Hastings \, A short proof of stability of topological order under local perturb ations\, Commun. Math. Phys. 307\, pp. 609-627 (2011) [3] S. Michalaki s and J. Zwolak\, Stability of Frustration-Free Hamiltonians\, Commun. Math. Phys. 322\, pp. 277-302 (2013) DTSTART:20191212T151500Z DTEND:20191212T170000Z LOCATION:Übung 1 / 01.250-128\, Cauerstr. 11\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik UID:1bd499e3-93b2-496c-a74b-790bb04a5770 DESCRIPTION:Vortrag faellt aus wg. Erkrankung! (Non-deterministic bill iards) Manuel Quaschner Abstract: In [Kn18]\, a simple non-determinist ic model with three particles was introduced in order to approximate t he orbits of solutions of a Hamiltonian equation with admissible poten tial and at most four bodies that do not have an asymptotic velocity. In these non-deterministic models\, near-collisions are substituted by collisions without conservation of kinetic energy. In order to approx imate the orbits some properties of non-deterministic models with thre e particles had to be derived such as the exponential growth (in the n umber of collisions) of the total kinetic energy and of the moment of inertia or a bound on the angular momenta of each particle in terms of the total angular momentum. All these properties fail to hold in gene ral\, if one considers non-deterministic models with more than three p articles. Our aim is to investigate these models and derive similar re sults to the results in the case of three particles. Therefor we have to define another number of collisions in which the growth of the abov e quantities is exponential by considering a reduced ordered systems o f particles moving on a line. DTSTART:20200116T151500Z DTEND:20200116T170000Z LOCATION:U1\, Cauerstr. 11\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik UID:03284014-3ceb-4167-a2d3-fbd1fa5b64c6 DESCRIPTION:The Cayley transform and K-theory Dr. Chris Bourne (RIKEN\ , Tohoku) Abstract: The Cayley transform gives a passage between unita ry operators and self-adjoint (unbounded) operators on a Hilbert space . I will review this construction and its generalisation to Hilbert C* -modules\, where the Cayley transform furnishes an isomorphism on (odd ) K-theory. Next\, we consider a graded analogue of these results and their application to bulk and boundary invariants of topological phase s. This is joint work with Johannes Kellendonk and Adam Rennie. DTSTART:20200123T031500Z DTEND:20200123T050000Z LOCATION:U1\, Cauerstr. 11\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik UID:fb3bce58-788b-46cf-9e6c-7a4723427407 DESCRIPTION:Transfer matrices for Hermitian operators of higher dimens ions Christian Sadel (Santiago de Chile) Abstract: We show how a formu la by Carmona for the spectral measure of a half line Jacobi operator generalizes to general Hermitian operators of locally finite hopping t ype. We use products of sets of rectangular\, radial transfer matrices for the spectral analysis. As corollaries we receive criteria for pro ving a.c. spectrum. These criteria are applied to certain models with disorder. DTSTART:20190716T143000Z DTEND:20190716T163000Z LOCATION:H13\, Cauerstr. 11\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik UID:bf101c68-2352-4f10-98b6-5c849f3c71ab DESCRIPTION:Das inverse Henderson-Problem Sabine Jansen (LMU Muenchen) The inverse Henderson problem of statistical mechanics concerns class ical particles in continuous space which interact according to a pair potential depending on the distance of the particles. Roughly stated\, it asks for the interaction potential given the equilibrium pair corr elation function of the system. In 1974 Henderson proved that this pot ential is uniquely determined in a canonical ensemble and he claimed t he same result for the thermodynamical limit of the physical system. H ere we provide a rigorous proof of a slightly more general version of the latter statement using Georgii’\;s version of the Gibbs varia tional principle. DTSTART:20190718T141500Z DTEND:20190718T160000Z LOCATION:Übung 1 / 01.250-128\, Cauerstr. 11\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik UID:40daf6a5-9d67-432b-a057-a40c201d04ff DESCRIPTION:Scattering Theory on Resonances in Quantum Field Theory Mi guel Ballesteros (UNAM) DTSTART:20190723T141500Z DTEND:20190723T163000Z LOCATION:Zi. 02.315\, Cauerstr. 11\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik UID:6d60a8f5-4230-4dbd-9dfc-8f69ace8ca0c DESCRIPTION:Douglas Lundholm Exchange and exclusion for non-abelian an yons Anyons are effective particles arising in certain 2D quantum syst ems and having properties intermediate to bosons and fermions. Roughly speaking\, they may be defined by representing an exchange of coordin ates of the many-body wave function by an arbitrary complex phase (abe lian anyons) or\, more generally\, a unitary matrix (non-abelian anyon s). I will discuss how to extend many-body methods of exchange and exc lusion to the case of non-abelian anyons\, focusing on two of the most popular such models: the Fibonacci and the Ising anyon models. This i s joint work with Viktor Qvarfordt. DTSTART:20190725T141500Z DTEND:20190725T160000Z LOCATION:Übung 1 / 01.250-128\, Cauerstr. 11\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik UID:134e88fd-c5b8-47fd-bdd9-15477db8f379 DESCRIPTION:The KO-valued spectral flow for skew-adjoint Fredholm oper ators Alan Carey (Canberra) Abstract: Talk about http://de.arxiv.org/a bs/1907.04981 DTSTART:20191029T153000Z DTEND:20191029T163000Z LOCATION:H13 DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik UID:d6cb5d02-6e95-468e-8aae-c3b83a623b9d DESCRIPTION:Andreas Knauf Morse-Theorie für Niveaumengen arXiv-Artike l mit Nikolay Martynchuk Abstract: Classical Morse theory proceeds by considering sublevel sets f -1((-&infin\;\, a]) of a Morse function f: M &rarr\; ℝ\;\, where M is a smooth finite-dimensional manifold. In this paper\, we study the topology of the level sets f -1(a) and g ive conditions under which their topology changes when passing a criti cal value. We show that for a general class of functions\, which inclu des all exhaustive Morse functions\, the topology of a regular level a lways changes when passing a single critical point\, unless the index of the critical point is half the dimension of the manifold M. When f is a natural Hamiltonian on a cotangent bundle\, we obtain more precis e results in terms of the topology of the configuration space. (Counte r-)examples and applications to celestial mechanics are also discussed . DTSTART:20191114T151500Z DTEND:20191114T170000Z LOCATION:Übung 1 / 01.250-128\, Cauerstr. 11\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik UID:f3e4263b-2c42-4c84-a580-e8570b8dcaf5 DESCRIPTION:Dominik Schroeder (ETH) Edge Universality for non-Hermitia n Random Matrices arXiv-Artikel DTSTART:20191121T151500Z DTEND:20191121T170000Z LOCATION:Übung 1 / 01.250-128\, Cauerstr. 11\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik UID:9931646d-76a0-4c61-ad07-8c17e14c7600 DESCRIPTION:An introduction to PT symmetric problems on a wedge shaped contour Referent: Prof. Carsten Trunk\, TU Ilmenau DTSTART:20190523T141500Z DTEND:20190523T160000Z LOCATION:Übung 1 / 01.250-128\, Cauerstr. 11\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik UID:0b39180a-425d-4e56-884d-e96c8eb961e9 DESCRIPTION:Projective dynamics\, first integrals and symmetries Refer ent: Alain Albouy\, Paris DTSTART:20190613T141500Z DTEND:20190613T160000Z LOCATION:Übung 1 / 01.250-128\, Cauerstr. 11\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT BEGIN:VEVENT SUMMARY:AG Mathematische Physik UID:f09cc9c2-77ce-432e-af63-cab5ea35fdfd DESCRIPTION:Vojkan Jaksic\, McGill University\, Montreal On a mathemat ical theory of repeated quantum measurements The statistics of the (fi nite alphabet) outcomes of repeated quantum measurements is studied by methods of thermodynamic formalism. Viewed as one-dimensional spin sy s- tems with long range interactions\, repeated quantum measurements e xhibit very rich (and sometimes very singular) thermodynamic behaviour . We will describe general thermodynamical formalism of these systems and illustrate its unexpected features on a number of examples. DTSTART:20190618T080000Z DTEND:20190618T100000Z LOCATION:02.315\, Cauerstr. 11\, Erlangen DTSTAMP:20261008T194011Z END:VEVENT END:VCALENDAR