English

Shortened universal cycles for permutations

Combinatorics 2023-08-14 v2

Abstract

Kitaev, Potapov, and Vajnovszki [On shortening u-cycles and u-words for permutations, Discrete Appl. Math, 2019] described how to shorten universal words for permutations, to length n!+n1i(n1)n!+n-1-i(n-1) for any i[(n2)!]i \in [(n-2)!], by introducing incomparable elements. They conjectured that it is also possible to use incomparable elements to shorten universal cycles for permutations to length n!i(n1)n!-i(n-1) for any i[(n2)!]i \in [(n-2)!]. In this note we prove their conjecture. The proof is constructive, and, on the way, we also show a new method for constructing universal cycles for permutations.

Keywords

Cite

@article{arxiv.2204.02910,
  title  = {Shortened universal cycles for permutations},
  author = {Rachel Kirsch and Bernard Lidický and Clare Sibley and Elizabeth Sprangel},
  journal= {arXiv preprint arXiv:2204.02910},
  year   = {2023}
}

Comments

13 pages, 10 figures

R2 v1 2026-06-24T10:40:03.310Z