Characterization and chromatic number of triangle-free graphs with diameter 2

Akihiro Higashitani, Diogo Kendy Matsumoto, Naoki Matsumoto

In this paper, we consider triangle-free graphs with diameter 2. If a triangle-free graph $G$ with diameter 2 is not isomorphic to a star, then the radius of $G$ is also 2, where s…