English

A Tur\'an-type problem on distance two

Combinatorics 2013-12-05 v1

Abstract

A new tur\'an-type problem on distances on graphs was introduced by Tyomkyn and Uzzell. In this paper, we focus on the case that the distance is two. We primely show that for any value of nn, a graph on nn vertices without three vertices pairwise at distance 22, if it has a vertex vV(G)v \in V(G), whose neighbours are covered by at most two cliques, then it has at most (n21)/4+1(n^2 - 1)/4 + 1 pairs of vertices at distance 22. This partially answers a guess of Tyomkyn and Uzzell [Tyomkyn, M., Uzzell, A.J.: A new Tur\'an-Type promble on distaces of graphs. Graphs Combin. {\bf 29}(6), 1927--1942 (2012)].

Keywords

Cite

@article{arxiv.1312.1013,
  title  = {A Tur\'an-type problem on distance two},
  author = {Xueliang Li and Jing Ma and Yongtang Shi and Jun Yue},
  journal= {arXiv preprint arXiv:1312.1013},
  year   = {2013}
}

Comments

10 pages, 4 figures

R2 v1 2026-06-22T02:20:16.452Z