Time: 13:30-14:30 September 22, 2021(Wednesday)

Place: MCM110

Title: Generalized Franchetta conjecture in Deligne-Beilinson cohomogy

Abstract: O'Grady's generalized Franchetta conjecture (GFC)  is concerned with codimension 2 algebraic cycles on universal polarized K3 surfaces. This has been confirmed in the Betti cohomology groups. Following a suggestion of Claire Voisin, we study this question in Deligne-Beilinson cohomolgoy. After introducing the Deligne-Beilinson cohomology theory on DM stacks, we show that GFC also holds in Deligne-Beilinson cohomology. This is a joint work with Zhang.