Algebraic Geometry Seminar: "Unramified cohomology and the integral Hodge conjecture"
Speaker: Humberto Diaz, Washington University in Saint Louis
Abstract: The failure of the integral Hodge conjecture has been known since the famous counterexamples of Atiyah and Hirzebruch. Currently, several methods exist for producing other counter -examples. For instance, a seminal result of Colliot-Th´el`ene and Voisin relates the failure of the integral Hodge conjecture in degree 4 to degree 3 unramified cohomology. After giving a quick overview of this method, I will discuss how it can be used to obtain new counterexamples to the integral Hodge conjecture.
Host: Matt Kerr