English

Stability for the Anti-Ramsey Number of Matchings

Combinatorics 2026-04-14 v1

Abstract

Let n,r,sn, r, s be three positive integers such that n2s+5n\geq 2s+5. Let KrK_r denote the complete graph of order rr. Given a graph FF, the anti-Ramsey number ar(n,F)ar(n,F) is defined as the minimum number CC such that any edge-coloring of KnK_n with exactly CC colors contains a rainbow copy of FF. Let HH be an edge-colored graph on KnK_n with at least g(n,s)g(n,s) colors, where g(n,s)=max{(n2)(ns+12)+5,(2s12)+n+1}. g(n,s)=\max\left\{ \binom{n}{2} - \binom{n - s + 1}{2} + 5, \binom{2s - 1}{2} + n + 1 \right\}. In this paper, we establish a stability type result for the anti-Ramsey number of matchings. Specifically, if HH does not have a rainbow matching of size s+2s+2, then HH contains either a monochromatic complete graph KnsK_{n-s} or a monochromatic Kn2s1K2s+1K_{n - 2s - 1} \vee \overline{K_{2s + 1}}.

Keywords

Cite

@article{arxiv.2604.11505,
  title  = {Stability for the Anti-Ramsey Number of Matchings},
  author = {Xuechun Zhang and Hongliang Lu},
  journal= {arXiv preprint arXiv:2604.11505},
  year   = {2026}
}