Expansion properties of metric spaces not admitting a coarse embedding into a Hilbert space
arXiv:0903.0607
Abstract
The main purpose of the paper is to find some expansion properties of locally finite metric spaces which do not embed coarsely into a Hilbert space. The obtained result is used to show that infinite locally finite graphs excluding a minor embed coarsely into a Hilbert space. In an appendix a direct proof of the latter result is given.
Some misprints have been corrected in the second version