English

A proof of the Total Coloring Conjecture

Combinatorics 2021-06-18 v3 Discrete Mathematics

Abstract

\textit{Total Coloring} of a graph is a major coloring problem in combinatorial mathematics, introduced in the early 19601960s. A \textit{total coloring} of a graph GG is a map f:V(G)E(G)Kf:V(G) \cup E(G) \rightarrow \mathcal{K}, where K\mathcal{K} is a set of colors, satisfying the following three conditions: 1. f(u)f(v)f(u) \neq f(v) for any two adjacent vertices u,vV(G)u, v \in V(G); 2. f(e)f(e)f(e) \neq f(e') for any two adjacent edges e,eE(G)e, e' \in E(G); and 3. f(v)f(e)f(v) \neq f(e) for any vertex vV(G)v \in V(G) and any edge eE(G)e \in E(G) that is incident to the same vertex vv. The \textit{total chromatic number}, χ(G)\chi''(G), is the minimum number of colors required for a \textit{total coloring} of GG. Behzad (1965), and Vizing (1968), conjectured that for any graph GG χ(G)Δ+2\chi''(G)\leq \Delta + 2. This conjecture is one of the classic unsolved mathematical problems. In this paper, we settle this classical conjecture by proving that the \textit{total chromatic number} χ(G)\chi''(G) of a graph is indeed bounded above by Δ+2\Delta+2. Our novel approach involves algebraic settings over a finite field Zp\mathbb{Z}_p and Vizing's theorem is an essential part of the algebraic settings.

Keywords

Cite

@article{arxiv.2003.09658,
  title  = {A proof of the Total Coloring Conjecture},
  author = {T Srinivasa Murthy},
  journal= {arXiv preprint arXiv:2003.09658},
  year   = {2021}
}

Comments

No major changes in this third-version apart from addition of Remark 3.5, corrections of typos, and some minor refinements in explanation as and where it was necessary

R2 v1 2026-06-23T14:22:30.282Z