Groups with no coarse embeddings into hyperbolic groups
Abstract
We introduce an obstruction to the existence of a coarse embedding of a given group or space into a hyperbolic group, or more generally into a hyperbolic graph of bounded degree. The condition we consider is "admitting exponentially many fat bigons", and it is preserved by a coarse embedding between graphs with bounded degree. Groups with exponential growth and linear divergence (such as direct products of two groups one of which has exponential growth, solvable groups that are not virtually nilpotent, and uniform higher-rank lattices) have this property and hyperbolic graphs do not, so the former cannot be coarsely embedded into the latter. Other examples include certain lacunary hyperbolic and certain small cancellation groups.
Cite
@article{arxiv.1702.03789,
title = {Groups with no coarse embeddings into hyperbolic groups},
author = {David Hume and Alessandro Sisto},
journal= {arXiv preprint arXiv:1702.03789},
year = {2017}
}
Comments
13 pages, 1 figure, accepted for publication in NYJM