$L^2$ invariants and Benjamini-Schramm convergence

$L^2$ invariants and Benjamini-Schramm convergence

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Lewis Bowen, University of Texas, Austin & Princeton University
Fine Hall 110

Does there exist a sequence of free subgroups $F_k$ of the isometry group of hyperbolic $n$-space such that the Cheeger constant of the quotient space $H^n/F_k$ tends to zero as $k$ tends to infinity?  I will explain how to answer this (and related questions) when $n$ is even using a curious result of $G$.

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