(2P2, K4)-Free Graphs are 4-Colorable

/ Authors

/ Abstract

In this paper, we show that every $(2P_2,K_4)$-free graph is 4-colorable. The bound is attained by the five-wheel and the complement of seven-cycle. This answers an open question by Wagon \cite{Wa80} in 1980s.

Journal: SIAM J. Discret. Math.

DOI: 10.1137/18m1205832

(2P2, K4)-Free Graphs are 4-Colorable

/ Authors

Serge Gaspers, Shenwei Huang

/ Abstract

In this paper, we show that every $(2P_2,K_4)$-free graph is 4-colorable. The bound is attained by the five-wheel and the complement of seven-cycle. This answers an open question by Wagon \cite{Wa80} in 1980s.

Journal: SIAM J. Discret. Math.

DOI: 10.1137/18m1205832