We prove a conjecture of András Gyárfás, that for all k, l, every graph with clique number at most κ and sufficiently large chromatic number has an odd hole of length at least ℓ.
Maria Chudnovsky, Alex Scott, Paul Seymour, Sophie Spirkl
(2020).
Induced subgraphs of graphs with large chromatic number. VIII. Long odd holes. UWSpace.
http://hdl.handle.net/10012/18528