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Emphasis Period Seminar: Donaldson-Thomas invariants are weighted Euler Characteristics
Wed, March 18, 2009 1:30PM - 3:00PM
Time:1:30PM - 3:00PM
Location:Baker Board Room #245
Speakers:Kai Behrend, Kai Behrend
Abstract:I will explain why the counting invariants for sheaves on Calabi-Yau threefolds a la Donaldson-Thomas are equal to weighted Euler characteristics of the moduli spaces involved. Each sheaf, i.e., each point in the moduli space, contributes an integer weight to the sheaf count. In good cases this integer weight is related to the Milnor fibre of a Chern-Simons type function.