I gave an invited talk at the Large Cardinals and Forcing meeting, Erwin Schrödinger International Institute for Mathematical Physics, Vienna, September 23–27, 2013.

**Talk Title:** Hedetniemi’s conjecture for uncountable graphs

**Abstract:** It is proved that in Godel’s constructible universe, for every successor cardinal $\kappa$, there exist graphs $\mathcal G$ and $\mathcal H$ of size and chromatic number $\kappa$, for which the tensor product graph $\mathcal G\times\mathcal H$ is countably chromatic.

This solves a longstanding open problem of Hajnal, and establishes the independence of the infinite weak Hedetniemi conjecture from ZFC.

**Downloads:**

Slides are now available!

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