English

Macroscopic scalar curvature and local collapsing

Differential Geometry 2020-06-02 v1

Abstract

Consider a closed Riemannian nn-manifold MM admitting a negatively curved Riemannian metric. We show that for every Riemannian metric on MM of sufficiently small volume, there is a point in the universal cover of MM such that the volume of every ball of radius r1r \geq 1 centered at this point is greater or equal to the volume of the ball of the same radius in the hyperbolic nn-space. We also give an interpretation of this result in terms of macroscopic scalar curvature. This result, which holds more generally in the context of polyhedral length spaces, is related to a question of Guth. Its proof relies on a generalization of recent progress in metric geometry about the Alexandrov/Urysohn width involving the volume of balls of radius in a certain range with collapsing at different scales.

Keywords

Cite

@article{arxiv.2006.00663,
  title  = {Macroscopic scalar curvature and local collapsing},
  author = {Stéphane Sabourau},
  journal= {arXiv preprint arXiv:2006.00663},
  year   = {2020}
}
R2 v1 2026-06-23T15:56:57.236Z