|Speaker:||Yu Nakayama (Caltech)|
|Title:||Refined topological string for Omega background|
|Date:||Tue, Jun 14, 2011, 13:15 - 14:45|
|Place:||Seminar Room A|
Nekrasov's partition function is defined on a flat bundle of $R4$ over $S1$ called the Omega background.
When the fibration is self-dual, Nekrasov's partition function is equal to the topological string partition function, which computes scattering amplitudes of self-dual gravitons and graviphotons in type II superstring on a Calabi-Yau manifold. We propose worldsheet string theory interpretation for the general Omega background where the fibration is not necessarily self-dual.