English

A Ramsey Type problem for highly connected subgraphs

Combinatorics 2023-03-22 v4

Abstract

Bollob\'{a}s and Gy\'{a}rf\'{a}s conjectured that for any k,nZ+k, n \in \mathbb{Z}^+ with n>4(k1)n > 4(k-1), every 2-edge-coloring of the complete graph on nn vertices leads to a kk-connected monochromatic subgraph with at least n2k+2n-2k+2 vertices. We find a counterexample with n=5k2.58k314n = \lfloor 5k-2.5-\sqrt{8k-\frac{31}{4}} \rfloor, thus disproving the conjecture, and we show the conclusion holds for n>5k2.58k314n > 5k-2.5-\sqrt{8k-\frac{31}{4}} when k16k \ge 16.

Keywords

Cite

@article{arxiv.2008.09001,
  title  = {A Ramsey Type problem for highly connected subgraphs},
  author = {Chunlok Lo and Hehui Wu and Qiqin Xie},
  journal= {arXiv preprint arXiv:2008.09001},
  year   = {2023}
}
R2 v1 2026-06-23T17:59:34.232Z