Longest odd cycles in non-bipartite $C_{2k+1}$-free graphs

Rui Wang, Shipeng Wang

In strengthening a result of Andrásfai, Erdős and Sós in 1974, Häggkvist proved that if $G$ is an $n$-vertex $C_{2k+1}$-free graph with minimum degree $\delta (G)>\frac{2n}{2k+3}$ and $n…