Numberphile explains a recent breakthrough in graph theory A counterexample to Hedetniemi’s conjecture – featuring Erica Klarreich.

Read Erica Klarreich’s Quanta article on this subject: https://www.quantamagazine.org/mathematician-disproves-hedetniemis-graph-theory-conjecture-20190617/

And visit her website: http://www.ericaklarreich.com/

Yaroslav Shitov’s breakthrough paper: https://arxiv.org/abs/1905.02167