On color-critical ($P_5,{\overline{P}}_5$)-free graphs

Harjinder S. Dhaliwal, Angèle M. Hamel, Chính T. Hoàng +3

A graph is $k$-critical if it is $k$-chromatic but each of its proper induced subgraphs is ($k-1$)-colorable. It is known that the number of $4$-critical $P_5$-free graphs is finit…