English

Semigroup automorphisms of total positivity

Rings and Algebras 2026-01-19 v1

Abstract

Totally positive (TP) and totally nonnegative (TN) matrices connect to analysis, mechanics, and to dual canonical bases in reductive groups, by well-known works of Schoenberg, Gantmacher-Krein, Lusztig, and others. TP matrices form a multiplicatively closed semigroup, contained in the larger monoid of invertible totally nonnegative (ITN) matrices. Whitney and Berenstein-Fomin-Zelevinsky found bidiagonal factorizations of all n×nn\times n ITN and TP matrices into multiplicative generators; a natural question now is to classify the multiplicative automorphisms of these semigroups. In this article, we classify all automorphisms of these semigroups of ITN and TP matrices. In particular, we show that the automorphisms are the same, and they respect the multiplicative generators.

Keywords

Cite

@article{arxiv.2601.11059,
  title  = {Semigroup automorphisms of total positivity},
  author = {Projesh Nath Choudhury and Shaun Fallat and Chi-Kwong Li},
  journal= {arXiv preprint arXiv:2601.11059},
  year   = {2026}
}

Comments

18 pages, no figures

R2 v1 2026-07-01T09:07:10.237Z