| Date: |
August 4, Monday, 2008, 13:00 - 14:30 & 15:30 - 17:00 |
| Place: |
Seminar Room at IPMU Prefab. B, Kashiwa Campus of the University of Tokyo |
| Speaker: |
Nagao Kentaro (Kyoto University) |
| Title: |
Counting invariants of perverse coherent systems on CY 3-folds and their wall-crossings
|
| Abstract: |
A perverse coherent system on a CY 3-fold is a pair of perverse
coherent sheaf on the CY 3-fold and a morphism to it from the
structure sheaf.
We intruduce moduli spaces of perverse coherent systems and counting
invariants of them.
In order to construct a moduli space we should choose a parameter of stability.
We show that Donaldson-Thomas theory and Pandharipande-Thomas theory
can be recovered at specific parameters.
We also establish wall-crossing formulas for the generating functions
of counting invariants of perverse coherent systems.
As applications, we provide some formulas on DT invariants and PT invariants.
|
