# Dirk van Bree: Virasoro constraints for moduli spaces of sheaves on surfaces

**Time: **
Thu 2021-10-28 14.00 - 15.00

**Location: **
Institut Mittag-Leffler, Seminar Hall Kuskvillan (alt. Zoom, meeting ID: 921 756 1880)

**Participating: **
Dirk van Bree (Utrecht)

**Abstract: **The Virasoro constraints are a well-known conjecture in GW-theory. Recently, Moreira, Oblomkov, Okounkov and Pandharipande formulated versions for the PT-theory of a 3-fold and the Hilbert scheme of points on a surface. I will introduce a version of this conjecture for the moduli space of stable sheaves on a surface, generalising the Hilbert scheme case. Then I will explain how to verify this conjecture in a few explicit toric cases. This involves a combinatorial description of equivariant sheaves which is originally due to Klyachko.