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arXiv · 2206.14251

Co-spectral radius of intersections

Mikolaj Fraczyk·Wouter van Limbeek
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Abstract

We study the behavior of the co-spectral radius of a subgroup $H$ of a discrete group $\Gamma$ under taking intersections. Our main result is that the co-spectral radius of an invariant random subgroup does not drop upon intersecting with a deterministic co-amenable subgroup. As an application, we find that the intersection of independent co-amenable invariant random subgroups is co-amenable.

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Mikolaj Fraczyk, Wouter van Limbeek. 2022-06-28. Co-spectral radius of intersections. https://arxiv.org/abs/2206.14251

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