English

Warped cones and proper affine isometric actions of discrete groups on Banach spaces

Metric Geometry 2017-05-24 v1 Dynamical Systems Group Theory

Abstract

Warped cones are metric spaces introduced by John Roe from discrete group actions on compact metric spaces to produce interesting examples in coarse geometry. We show that a certain class of warped cones OΓ(M)\mathcal{O}_\Gamma (M) admit a fibred coarse embedding into a LpL_p-space (1p<1\leq p<\infty) if and only if the discrete group Γ\Gamma admits a proper affine isometric action on a LpL_p-space. This actually holds for any class of Banach spaces stable under taking Lebesgue-Bochner LpL_p-spaces and ultraproducts, e.g., uniformly convex Banach spaces or Banach spaces with nontrivial type. It follows that the maximal coarse Baum-Connes conjecture and the coarse Novikov conjecture hold for a certain class of warped cones which do not coarsely embed into any LpL_p-space for any 1p<1\leq p<\infty.

Keywords

Cite

@article{arxiv.1705.08090,
  title  = {Warped cones and proper affine isometric actions of discrete groups on Banach spaces},
  author = {Qin Wang and Zhen Wang},
  journal= {arXiv preprint arXiv:1705.08090},
  year   = {2017}
}