Barcelona Algebraic Topology Group
Friday's Topology Seminar 201819 



Written by Natàlia Castellana Vila

Friday, 30 November 2018 14:12 
Speaker: Marc Stephan (MPI, Bonn) Title: A multiplicative spectral sequence for free pgroup actions Place: Room Seminar C3b Date: Friday May 24th, 12h13h
Abstract: Carlsson conjectured that if a finite CW complex admits a free action by an elementary abelian pgroup G of rank n, then the sum of its modp Betti numbers is at least 2^n. In 2017, Iyengar and Walker constructed equivariant chain complexes that are counterexamples to an algebraic version of Carlsson’s conjecture. This raised the question if these chain complexes can be realized topologically by free Gspaces to produce counterexamples to Carlsson’s conjecture. In this talk, I will explain multiplicative properties of the spectral sequence obtained by filtering the modp cochains of a space with a free pgroup action by powers of the augmentation ideal and deduce that the counterexamples can not be realized topologically. This is joint work with Henrik Rüping.
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Last Updated on Friday, 17 May 2019 10:25 
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This is the web site of the Algebraic Topology Team in Barcelona (Grup de Topologia Algebraica de Barcelona, 2014SGR42 and Homotopy theory of algebraic structures, MTM201680439P).
Our research interests include a variety of subjects in algebraic topology, group theory, homological algebra, and category theory. Here you will find information about us and our common activities. 

