Revisiting a theorem by Folkman on graph colouring [article]

Marthe Bonamy and Pierre Charbit and Oscar Defrain and Gwenaël Joret and Aurélie Lagoutte and Vincent Limouzy and Lucas Pastor and Jean-Sébastien Sereni
2019 arXiv   pre-print
We give a short proof of the following theorem due to Jon H. Folkman (1969): The chromatic number of any graph is at most 2 plus the maximum over all subgraphs of the difference between half the number of vertices and the independence number.
arXiv:1907.11429v1 fatcat:p22hs6m57jfcxi3uzjhv46ew2a