English

Erd\H{o}s-Szekeres theorem for cyclic permutations

Combinatorics 2018-10-17 v2

Abstract

We provide a cyclic permutation analogue of the Erd\H os-Szekeres theorem. In particular, we show that every cyclic permutation of length (k1)(1)+2(k-1)(\ell-1)+2 has either an increasing cyclic sub-permutation of length k+1k+1 or a decreasing cyclic sub-permutation of length +1\ell+1, and show that the result is tight. We also characterize all maximum-length cyclic permutations that do not have an increasing cyclic sub-permutation of length k+1k+1 or a decreasing cyclic sub-permutation of length +1\ell+1.

Keywords

Cite

@article{arxiv.1804.02578,
  title  = {Erd\H{o}s-Szekeres theorem for cyclic permutations},
  author = {Éva Czabarka and Zhiyu Wang},
  journal= {arXiv preprint arXiv:1804.02578},
  year   = {2018}
}

Comments

8 pages, 2 figures

R2 v1 2026-06-23T01:16:58.459Z