English

Approximate isoperimetry for convex polytopes

Metric Geometry 2025-09-18 v1 Functional Analysis

Abstract

For all n,ϕNn,\phi\in \mathbb{N} with ϕn+1\phi\geqslant n+1, the smallest possible isoperimetric quotient of an nn-dimensional convex polytope that has ϕ\phi facets is shown to be bounded from above and from below by positive universal constant multiples of max{n/1+log(ϕ/n),n}\max\big\{n/\sqrt{1+\log (\phi/n)},\sqrt{n}\big\}. For all nNn\in \mathbb{N} and 2nβ2N2n\leqslant \beta\in 2\mathbb{N}, it is shown that every nn-dimensional origin-symmetric convex polytope that has β\beta vertices admits an affine image whose isoperimetric quotient is at most a universal constant multiple of min{log(β/n),n}\min\big\{\sqrt{\log(\beta/n)},n\big\}, which is sharp. The weak isomorphic reverse isoperimetry conjecture is proved for nn-dimensional convex polytopes that have O(n)O(n) facets by demonstrating that any such polytope KK has an image KK' under a volume preserving matrix and a convex body LKL\subseteq K' such that the isoperimetric quotient of LL is at most a universal constant multiple of n\sqrt{n}, and also voln(L)/voln(K)n\sqrt[n]{\mathrm{vol}_n(L)/\mathrm{vol}_n(K)} is at least a positive universal constant.

Keywords

Cite

@article{arxiv.2509.13898,
  title  = {Approximate isoperimetry for convex polytopes},
  author = {Keith Ball and Károly J. Böröczky and Assaf Naor},
  journal= {arXiv preprint arXiv:2509.13898},
  year   = {2025}
}
R2 v1 2026-07-01T05:41:44.957Z