Time：11:00pm-12:00pm, Set 28, Friday
Location：Room 302, Library
Speaker: Junwu Tu
Title: Computing a categorical Gromov-Witten invariant (Joint work with Andrei Caldararu)
Abstract: We compute the g = 1, n = 1 B-model Gromov-Witten invariant of an elliptic curve E directly from the derived category of coherent sheaves on E. More precisely, we carry out the computation of the categorical Gromov-Witten invariant defined by Costello using as target a cyclic A-infinity model due to Polishchuk. This is the first non-trivial computation of a positive genus categorical GromovWitten invariant, and the result agrees with the prediction of mirror symmetry: it matches the classical (non-categorical) Gromov-Witten invariants of a symplectic 2-torus computed by Dijkgraaf.