On shortening universal words for multi-dimensional permutations

Kitaev, Sergey and Qiu, Dun (2026) On shortening universal words for multi-dimensional permutations. Discrete Mathematics, 349 (8). 115081. ISSN 0012-365X (https://doi.org/10.1016/j.disc.2026.115081)

[thumbnail of Kitaev-Qiu-DM-2026-On-shortening-universal-words-for-multi-dimentional]
Preview
Text. Filename: Kitaev-Qiu-DM-2026-On-shortening-universal-words-for-multi-dimentional.pdf
Final Published Version
License: Creative Commons Attribution 4.0 logo

Download (405kB)| Preview

Abstract

A universal word (u-word) for d-dimensional permutations of length nis a 2-dimensional word with d−1rows, any size nwindow of which is order-isomorphic to exactly one permutation of length n, and all permutations of length nare covered. It is known that u-words (in fact, even u-cycles, a stronger claim) for d-dimensional permutations exist. In this paper, we use the idea of incomparable elements to prove that u-words of length (n!)d−1+n−1−i(n−1), for d≥2 and 0≤i≤2d−1n−1[︄(1+(n−1)!)d−1−(︃1+(n−1)!2 )︃d−1]︄, for d-dimensional permutations of length nexist, which generalizes the respective result of Kitaev, Potapov and Vajnovszki for permutations (d=2).

ORCID iDs

Kitaev, Sergey ORCID logoORCID: https://orcid.org/0000-0003-3324-1647 and Qiu, Dun;