Date: Wednesday, February 27, 2013
Location: 3088 East Hall (4:00 PM to 6:00 PM)
Title: Categorification of DT invariants and GV numbers
Abstract: DT invariants are degrees of the virtual cycles of the moduli of sheaves on Calabi-Yau threefolds. Behrend's function allows to reconstruct these invariants via weighted Euler numbers, thus can define DT-invariants motivically. A categorification of DT invariants search for perverse sheaves on these moduli spaces so the Behrend function is the local Euler numbers of cohomology sheaves of these perverse sheaves. In a joint work with YH Kiem, we construct such perverse sheaves, with MHM structures. As a corollary, we define GV numbers via a double sl2 representations on 2-branes.
Speaker: Jun Li
Institution: Stanford
Event Organizer:
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