Vertex-critical co-gem-free graphs

Manoj Belavadi, T. Karthick

Given a graph $G$, let $\chi (G)$ denote the chromatic number of $G$. For $k\in \mathbb{N}$, a graph $G$ is $k$-$vertex$-$critical$ if $\chi (G)=k$ and $\chi (G-v)<k$ for all $v\in V(G)$. A r…