English

Exponential anticoncentration of the permanent

Probability 2025-09-29 v1 Combinatorics

Abstract

Let ARn×nA\in\mathbb{R}^{n\times n} be a random matrix with independent entries, and suppose that the entries are "uniformly anticoncentrated" in the sense that there is a constant ε>0\varepsilon>0 such that each entry aija_{ij} satisfies supzPr[aij=z]1ε\sup_{z}\Pr[a_{ij}=z]\le1-\varepsilon (for example, AA could be a uniformly random n×nn\times n matrix with ±1\pm1 entries). Significantly improving previous bounds of Tao and Vu, we prove that the permanent of AA is exponentially anticoncentrated: there is cε>0c_{\varepsilon}>0 such that supzPr[per(A)=z]exp(cεn)\sup_{z}\Pr[\operatorname{per}(A)=z]\le\exp(-c_{\varepsilon}n). Our proof also works for the determinant, giving an alternative proof of a classical theorem of Kahn, Koml\'os and Szemer\'edi. As a consequence, we see that there are at least exponentially many different permanents of n×nn\times n matrices with ±1\pm1 entries, resolving a problem of Ingram and Razborov.

Keywords

Cite

@article{arxiv.2509.22577,
  title  = {Exponential anticoncentration of the permanent},
  author = {Zach Hunter and Matthew Kwan and Lisa Sauermann},
  journal= {arXiv preprint arXiv:2509.22577},
  year   = {2025}
}

Comments

12 pages. Comments welcome!

R2 v1 2026-07-01T05:59:13.548Z