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Amenable actions and exactness for discrete groups

Narutaka Ozawa
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Abstract

It is proved that a discrete group G is exact if and only if its left translation action on the Stone-Cech compactification is amenable. Combining this with an unpublished result of Gromov, we have the existence of non exact discrete groups.

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Narutaka Ozawa. 2000-02-26. Amenable actions and exactness for discrete groups. https://doi.org/10.1016/s0764-4442(00)00248-2

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