A Breakthrough in Graph Theory

A counterexample to Hedetniemi's conjecture - featuring Erica Klarreich.

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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

Thanks to Stephen Hedetniemi for providing us with photos and pages from his original dissertation.

Some more graph theory on Numberphile...

Four Color Maps: https://youtu.be/NgbK43jB4rQ

An Unsolved Problem: https://youtu.be/niaeV_NHh-o

Planar Graphs: https://youtu.be/xBkTIp6ajAg

Perfect Graphs: https://youtu.be/C4Zr4cOVm9g

Friends and Strangers: https://youtu.be/xdiL-ADRTxQ

River Crossings: https://youtu.be/ZCVAGb1ee8A