3.30 pm, Seminar Hall An introduction to Donaldson-Thomas invariants Barbara Fantechi SISSA, Trieste, Italy. 22-01-14 Abstract 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 et.al., of the D-T invariants.
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