On geodesic homotopies of controlled width and conjugacies in isometry groups

Abstract

We give an analytical proof of the Poincare-type inequalities for widths of geodesic homotopies between equivariant maps valued in Hadamard metric spaces. As an application we obtain a linear bound for the length of an element conjugating two finite lists in a group acting on an Hadamard space.

minor stylistic corrections; 15 pages