English

On the staircases of Gy\'arf\'as

Combinatorics 2019-12-02 v1

Abstract

Gy\'arf\'as investigated a geometric Ramsey problem on convex, separated, balanced, geometric Kn,nK_{n,n}. This led to appealing extremal problem on square 00-11 matrices. Gy\'arf\'as conjectured that any 00-11 matrix of size n×nn\times n has a staircase of size n1n-1. We introduce the non-symmetric version of Gy\'arf\'as' problem. We give upper bounds and in certain range matching lower bound on the corresponding extremal function. In the square/balanced case we improve the (4/5+ϵ)n(4/5+\epsilon)n lower bound of Cai, Gy\'arf\'as et al. to 5n/67/125n/6-7/12. We settle the problem when instead of considering maximum staircases we deal with the sum of the size of the longest 00- and 11-staircases.

Keywords

Cite

@article{arxiv.1511.03504,
  title  = {On the staircases of Gy\'arf\'as},
  author = {János Csányi and Peter Hajnal and Gábor V. Nagy},
  journal= {arXiv preprint arXiv:1511.03504},
  year   = {2019}
}

Comments

10 pages