Quasiisometric embeddings between right-angled Artin groups: flexibility

TL;DR

This paper characterizes when right-angled Artin groups on cycle graphs can be quasiisometrically embedded into each other, revealing many embeddings without subgroup relations and constructing exotic embeddings of the hyperbolic plane.

Contribution

It provides a complete characterization of quasiisometric embeddings between such groups and introduces new exotic embeddings, contrasting with their known rigidity.

Findings

Infinitely many quasiisometric embeddings without subgroup relations.

Construction of quasiisometric embeddings between graph products of cyclic groups.

Exotic embeddings of the hyperbolic plane in certain right-angled Artin groups.

Abstract

We give a complete characterisation of when the right-angled Artin group on one cycle graph can be quasiisometrically embedded in the right-angled Artin group on another cycle graph. In particular, we find infinitely many instances of quasiisometric embeddings where there is no subgroup relation. This contrasts with the fact that such groups are quasiisometrically rigid. More generally, we construct quasiisometric embeddings between graph products of finite or cyclic groups whose underlying graphs are cycles. As a special case, we obtain exotic quasiisometric embeddings of the hyperbolic plane in all right-angled Artin groups whose defining graph contains an induced cycle of length greater than four.