Johannes Kellendonk (Lyon I)
Ellis semigroup in symbolic dynamics
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 point wise convergence. Its topological and algebraic properties characterise 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 theory and present some recent results which arise in the context of symbolic dynamics, that is, for G = Z and X a space of symbolic sequences.