Odd Holes in Bull-Free Graphs
Maria Chudnovsky, Vaidy Sivaraman · SIAM Journal on Discrete Mathematics · 2018
The complexity of testing whether a graph contains an induced odd cycle of length at least five is currently unknown. In this paper we show that this test can be done in polynomial time if the input graph has no induced subgraph isomorphic to the bull (a triangle with two disjoint pendant edges).