Answering a question by Letzter and Snyder, we prove that for large enough k any n-vertex graph G with minimum degree at least 2k−11n and without odd cycles of length less than 2k+1 is 3-colourable. In fact, we prove a stronger result that works with a slightly smaller minimum degree.
@article{arxiv.2302.01875,
title = {Graphs with large minimum degree and no small odd cycles are $3$-colourable},
author = {Julia Böttcher and Nóra Frankl and Domenico Mergoni Cecchelli and Olaf Parczyk and Jozef Skokan},
journal= {arXiv preprint arXiv:2302.01875},
year = {2023}
}