English

Asymptotically optimal approximate Hadamard matrices

Combinatorics 2025-11-19 v1 Functional Analysis

Abstract

In this paper, we study approximate Hadamard matrices, that is, well-conditioned n×nn\times n matrices with all entries in {±1}\{\pm1\}. We show that the smallest-possible condition number goes to 11 as nn\to\infty, and we identify some explicit infinite families of approximate Hadamard matrices.

Keywords

Cite

@article{arxiv.2511.14653,
  title  = {Asymptotically optimal approximate Hadamard matrices},
  author = {Boris Alexeev and John Jasper and Dustin G. Mixon},
  journal= {arXiv preprint arXiv:2511.14653},
  year   = {2025}
}

Comments

See the ancillary files for putatively optimal matrices and Lean code

R2 v1 2026-07-01T07:43:42.275Z