English

A local isoperimetric inequality for balls with nonpositive curvature

Differential Geometry 2026-02-20 v2 Metric Geometry

Abstract

We show that small perturbations of the metric of a ball in Euclidean n-space to metrics with nonpositive curvature do not reduce the isoperimetric ratio. Furthermore, the isoperimetric ratio is preserved only if the perturbation corresponds to a homothety of the ball. These results establish a sharp local version of the Cartan-Hadamard conjecture.

Keywords

Cite

@article{arxiv.2505.11971,
  title  = {A local isoperimetric inequality for balls with nonpositive curvature},
  author = {Mohammad Ghomi and John Ioannis Stavroulakis},
  journal= {arXiv preprint arXiv:2505.11971},
  year   = {2026}
}

Comments

8 pages; Minor revisions. Accepted for publication in Int. Math. Res. Not. (IMRN)