Perfect matching covers of claw-free cubic graphs

Abstract

The Berge conjecture [Proc. London Math. Soc., 1979] asserts that every bridgeless cubic graph can be covered by five perfect matchings. The 5-cycle double cover conjecture, proposed independently by Preissmann (1981) and Celmins (1984), asserts that every bridgeless graph admits five even subgraphs such that every edge belongs to exactly two of them. Hakobyan and Mkrtchyan [Ars Math. Contemp., 2019] proved that the 5-cycle double cover conjecture holds if and only if every bridgeless claw-free cubic graph can be covered by four perfect matchings. In this paper, we prove that the Berge conjecture holds for bridgeless claw-free cubic graphs. Moreover, we show that every bridgeless claw-free cubic graph $G$ admits four perfect matchings that cover at least $\frac{299}{315}|E(G)|$ edges.