Chennai Mathematical Institute


3.30 pm, Seminar Hall
An introduction to Donaldson-Thomas invariants

Barbara Fantechi
SISSA, Trieste, Italy.


We recall Thomas' original definition of the Donaldson-Thomas invariants in the rank one case, introduce the notion of a symmetric obstruction theory and show that the D-T moduli spaces have one. We then present Behrend's theorem which allows one to define D-T invariants for non-compact Calabi-Yau three-folds. If time permits we will sketch the notion of derived symplectic stack and the categorification, due to Joyce, of the D-T invariants.