English

Anti-Ramsey Numbers for Spanning Linear Forests of 3-Vertex Paths and Matchings

Combinatorics 2026-05-14 v3

Abstract

A subgraph in an edge-colored graph is called rainbow if all its edges have distinct colors. For a graph GG and an integer nn, the anti-Ramsey number AR(n,G)AR(n,G) is the maximum number of colors in an edge-coloring of KnK_n that contains no rainbow copy of GG. We study AR(n,kP3tP2)AR(n, kP_3 \cup tP_2), where kP3tP2kP_3 \cup tP_2 is the linear forest of kk disjoint paths on three vertices and a matching of size tt. Recently, Jie and Jin [Discrete Appl. Math. 386 (2026) 30-57] determined this number for k2k\geq 2, tk23k+42t\geq\frac{k^2-3k+4}{2} and n=2t+3kn=2t+3k. Here we solve the spanning case n=3k+2tn=3k+2t for all k1k\ge1, t2t\ge2 with no extra restrictions.

Keywords

Cite

@article{arxiv.2509.25949,
  title  = {Anti-Ramsey Numbers for Spanning Linear Forests of 3-Vertex Paths and Matchings},
  author = {Ali Ghalavand and Xueliang Li},
  journal= {arXiv preprint arXiv:2509.25949},
  year   = {2026}
}