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arXiv · 2305.00796

Some comments on piecewise-projective groups of the line

Nicolas Monod
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Abstract

We consider groups of piecewise-projective homeomorphisms of the line which are known to be non-amenable using notably the Carriere--Ghys theorem on ergodic equivalence relations. Replacing that theorem by an explicit fixed-point argument, we can strengthen the conclusion and exhibit uncountably many "amenability gaps" between various piecewise-projective groups.

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Nicolas Monod. 2023-05-01. Some comments on piecewise-projective groups of the line. https://arxiv.org/abs/2305.00796

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