2008-09-19

Tomoo Matsumura, Cornell University

Stringy/Orbifold Cohomology Ring and Symmetric Product Orbifolds.

First, I will explain the definition of stringy cohomology ring of a global quotient orbifold [X/G], where X is a symplectic or almost complex manifold with a finite group action. Its relation to Chen-Ruan orbifold cohomology ring and Gromov-Witten invariants will be also explained. Then I will show the computational result of the stringy cohomology of symmetric product of an orbifold and its application to Ruan's crepant resolution conjecture.