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تسجيل مستخدم جديدAmenable groups and Hadamard spaces with a totally disconnected isometry group
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Pierre-Emmanuel Caprace
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Let $X$ be a locally compact Hadamard space and $G$ be a totally disconnected group acting continuously, properly and cocompactly on $X$. We show that a closed subgroup of $G$ is amenable if and only if it is (topologically locally finite)-by-(virtually abelian). We are led to consider a set $bdfine X$ which is a refinement of the visual boundary $bd X$. For each $x in bdfine X$, the stabilizer $G_x$ is amenable.
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