Approximate marked length spectrum rigidity in coarse geometry
Abstract
We compare the marked length spectra of isometric actions of groups with non-positively curved features. Inspired by the recent works of Butt we study approximate versions of marked length spectrum rigidity. We show that for pairs of metrics, the supremum of the quotient of their marked length spectra is approximately determined by their marked length spectra restricted to an appropriate finite set of conjugacy classes. Applying this to fundamental groups of closed negatively curved Riemannian manifolds allows us to refine Butt's result. Our results however apply in greater generality and do not require the acting group to be hyperbolic. For example we are able to compare the marked length spectra associated to mapping class groups acting on their Cayley graphs or on the curve graph.
Cite
@article{arxiv.2410.01965,
title = {Approximate marked length spectrum rigidity in coarse geometry},
author = {Stephen Cantrell and Eduardo Reyes},
journal= {arXiv preprint arXiv:2410.01965},
year = {2024}
}
Comments
18 pages. This is an expansion of Sections 7 and 8 in V1 of arXiv:2304.13209 . V2 of that preprint does not include Sections 7 and 8 as V1 has been split into two (V2 and this preprint)