The Baum-Connes conjecture and proper group actions on affine buildings

Dmitry Matsnev

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arXiv · math/0703923

The Baum-Connes conjecture and proper group actions on affine buildings

Dmitry Matsnev

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Abstract

We study the possibility of applying a finite-dimensionality argument in order to address parts of the Baum-Connes conjecture for finitely generated linear groups. This gives an alternative approach to the results of Guentner, Higson, and Weinberger concerning the Baum-Connes conjecture for linear groups. For any finitely generated linear group over a field of characteristic zero we construct a proper action on a finite-asymptotic-dimensional CAT(0)-space, provided that for such a group its unipotent subgroups have `bounded composition rank'. The CAT(0)-space in our construction is a finite product of symmetric spaces and affine Bruhat-Tits buildings. For the case of finitely generated subgroup of SL(2,C) the result is sharpened to show that the Baum-Connes assembly map is an isomorphism.

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BibTeX RIS

Dmitry Matsnev. 2007-03-30. The Baum-Connes conjecture and proper group actions on affine buildings. https://arxiv.org/abs/math/0703923

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