Speaker:  Miguel Moreira  (ETH)

Abstract: Virasoro constraints for Gromov-Witten invariants have a rich history tied to the very beginning of the subject, but recently there have been many developments on the sheaf side. In this talk I will survey those developments and talk about joint work with A. Bojko and W. Lim where we propose a general conjecture of Virasoro constraints for moduli spaces of sheaves and formulate it using the vertex algebra that D. Joyce recently introduced to study wall-crossing. Using Joyce's framework we can show compatibility between wall-crossing and the constraints, which we then use to prove that they hold for moduli of stable sheaves on curves and surfaces with h^0,1=h^0,2=0.