Affiliation:
University of Wisconsin-Milwaukee/MPIM
Date:
Mon, 16/05/2022 - 09:30 - 10:30
Suppose a group \(G\) has a finite \(K(G,1)\) space \(X\), and suppose we have a sequence of deeper and deeper regular finite sheeted covers of \(X\), so that the corresponding sequence of normal subgroups intersect at \(\{1\}\). What can we say about homology of these covers? Rationally, the answer is given by the celebrated Lück Approximation theorem: the normalized Betti numbers of the covers limit to the \(\ell^2\)-Betti numbers of \(G\).