English

Metrics on permutations with the same peak set

Combinatorics 2024-01-22 v1

Abstract

Let SnS_n be the symmetric group on the set {1,2,,n}\{1,2,\ldots,n\}. Given a permutation σ=σ1σ2σnSn\sigma=\sigma_1\sigma_2 \cdots \sigma_n \in S_n, we say it has a peak at index ii if σi1<σi>σi+1\sigma_{i-1}<\sigma_i>\sigma_{i+1}. Let Peak(σ)\text{Peak}(\sigma) be the set of all peaks of σ\sigma and define P(S;n)={σSnPeak(σ)=S}P(S;n)=\{\sigma\in S_n\, | \,\text{Peak}(\sigma)=S\}. In this paper we study the Hamming metric, \ell_\infty-metric, and Kendall-Tau metric on the sets P(S;n)P(S;n) for all possible SS, and determine the minimum and maximum possible values that these metrics can attain in these subsets of SnS_n.

Keywords

Cite

@article{arxiv.2401.10719,
  title  = {Metrics on permutations with the same peak set},
  author = {Alexander Diaz-Lopez and Kathryn Haymaker and Kathryn Keough and Jeongbin Park and Edward White},
  journal= {arXiv preprint arXiv:2401.10719},
  year   = {2024}
}

Comments

7 pages, 3 tables

R2 v1 2026-06-28T14:21:37.130Z