Predavatelj: Damian Osajda (Uniwersytet Wroclawski, Poljska)

Abstract: The talk will concern cell-complexes associated with various classes of (infinite) graphs–in particular (weakly) bridged graphs. For such complexes the Fixed Point Theorem asserts that any finite group action admits a point fixed by every element of the group. I will present a way of proving such results using a graph-theoretical tool–the "dismantlability" or "cop-win" property. The Fixed Point Theorem has many group-theoretical and topological consequences. 
This is joint work with Victor Chepoi from Marseille.