A note on transformations of edge colorings of chordless graphs and triangle-free graphs

Abstract

Bonamy et al. (2023) proved that an optimal edge coloring of a simple triangle--free graph $G$ can be reached from any given proper edge coloring of $G$ through a series of Kempe changes. We show that a small modification of their proof gives a possibility to obtain a similar result for a larger class of simple graphs consisting of all triangle-free and all chordless graphs (a graph $G$ is chordless if in every cycle $C$ of $G$ any two nonconsecutive vertices of $C$ are not adjacent).