Coarse differentiation of quasi-isometries I: Spaces not quasi-isometric to Cayley graphs

Abstract

In this paper, we prove that certain spaces are not quasi-isometric to Cayley graphs of finitely generated groups. In particular, we answer a question of Woess and prove a conjecture of Diestel and Leader by showing that certain homogeneous graphs are not quasi-isometric to a Cayley graph of a finitely generated group.
This paper is the first in a sequence of papers proving results announced in our 2007 article “Quasi-isometries and rigidity of solvable groups.” In particular, this paper contains many steps in the proofs of quasi-isometric rigidity of lattices in $\mathrm{Sol}$ and of the quasi-isometry classification of lamplighter groups. The proofs of those results are completed in “Coarse differentiation of quasi-isometries II; Rigidity for lattices in $\mathrm{Sol}$ and Lamplighter groups.” The method used here is based on the idea of coarse differentiation introduced in our 2007 article.

Authors

Alex Eskin

Department of Mathematics, University of Chicago, 5734 University Avenue, Chicago, IL 60637-1514

David Fisher

Department of Mathematics, Indiana University - Bloomington, 831 E. 3rd Street, Bloomington, IN 47401

Kevin Whyte

Department of Mathematics, Statistics, and Computer Science, University of Illinois at Chicago, 851 S. Morgan Street, Chicago, IL 60607-7045