English

Monochromatic disconnection: Erd\H{o}s-Gallai-type problems and product graphs

Combinatorics 2020-09-11 v2

Abstract

For an edge-colored graph GG, we call an edge-cut MM of GG monochromatic if the edges of MM are colored with a same color. The graph GG is called monochromatically disconnected if any two distinct vertices of GG are separated by a monochromatic edge-cut. The monochromatic disconnection number, denoted by md(G)md(G), of a connected graph GG is the maximum number of colors that are allowed to make GG monochromatically disconnected. In this paper, we solve the Erd\H{o}s-Gallai-type problems for the monochromatic disconnection, and give the monochromatic disconnection numbers for four graph products, i.e., Cartesian, strong, lexicographic, and tensor products.

Keywords

Cite

@article{arxiv.1904.08583,
  title  = {Monochromatic disconnection: Erd\H{o}s-Gallai-type problems and product graphs},
  author = {Ping Li and Xueliang Li},
  journal= {arXiv preprint arXiv:1904.08583},
  year   = {2020}
}

Comments

21 pages, 4 figures. In this new version we obtain the explicit expression for the extremal function $g(n,r)$, which was only an upper bound for the case $3\leq r \leq \lfloor \frac n 2 \rfloor - 1$ in the old version