English

Uniqueness of codes using semidefinite programming

Combinatorics 2018-12-03 v2 Optimization and Control

Abstract

For n,d,wNn,d,w \in \mathbb{N}, let A(n,d,w)A(n,d,w) denote the maximum size of a binary code of word length nn, minimum distance dd and constant weight ww. Schrijver recently showed using semidefinite programming that A(23,8,11)=1288A(23,8,11)=1288, and the second author that A(22,8,11)=672A(22,8,11)=672 and A(22,8,10)=616A(22,8,10)=616. Here we show uniqueness of the codes achieving these bounds. Let A(n,d)A(n,d) denote the maximum size of a binary code of word length nn and minimum distance dd. Gijswijt, Mittelmann and Schrijver showed that A(20,8)=256A(20,8)=256. We show that there are several nonisomorphic codes achieving this bound, and classify all such codes with all distances divisible by 4.

Keywords

Cite

@article{arxiv.1709.02195,
  title  = {Uniqueness of codes using semidefinite programming},
  author = {Andries E. Brouwer and Sven C. Polak},
  journal= {arXiv preprint arXiv:1709.02195},
  year   = {2018}
}

Comments

13 pages. Revisions have been made based on comments of the referees. Accepted for publication in Designs, Codes and Cryptography

R2 v1 2026-06-22T21:35:50.358Z