English

Total Equitable List Coloring

Combinatorics 2018-03-21 v1

Abstract

An equitable coloring is a proper coloring of a graph such that the sizes of the color classes differ by at most one. A graph GG is equitably kk-colorable if there exists an equitable coloring of GG which uses kk colors, each one appearing on either V(G)/k\lfloor |V(G)|/k \rfloor or V(G)/k\lceil |V(G)|/k \rceil vertices of GG. In 1994, Fu conjectured that for any simple graph GG, the total graph of GG, T(G)T(G), is equitably kk-colorable whenever kmax{χ(T(G)),Δ(G)+2}k \geq \max\{\chi(T(G)), \Delta(G)+2\} where χ(T(G))\chi(T(G)) is the chromatic number of the total graph of GG and Δ(G)\Delta(G) is the maximum degree of GG. We investigate the list coloring analogue. List coloring requires each vertex vv to be colored from a specified list L(v)L(v) of colors. A graph is kk-choosable if it has a proper list coloring whenever vertices have lists of size kk. A graph is equitably kk-choosable if it has a proper list coloring whenever vertices have lists of size kk, where each color is used on at most V(G)/k\lceil |V(G)|/k \rceil vertices. In the spirit of Fu's conjecture, we conjecture that for any simple graph GG, T(G)T(G) is equitably kk-choosable whenever kmax{χl(T(G)),Δ(G)+2}k \geq \max\{\chi_l(T(G)), \Delta(G)+2\} where χl(T(G))\chi_l(T(G)) is the list chromatic number of T(G)T(G). We prove this conjecture for all graphs satisfying Δ(G)2\Delta(G) \leq 2 while also studying the related question of the equitable choosability of powers of paths and cycles.

Keywords

Cite

@article{arxiv.1803.07450,
  title  = {Total Equitable List Coloring},
  author = {Hemanshu Kaul and Jeffrey A. Mudrock and Michael J. Pelsmajer},
  journal= {arXiv preprint arXiv:1803.07450},
  year   = {2018}
}

Comments

13 pages

R2 v1 2026-06-23T00:58:57.069Z