Talk page

Title:
Multiplicative vertex algebras and wall-crossing in equivariant K-theory

Speaker:
Henry Liu

Abstract:
K-theory is an interesting multiplicative refinement of cohomology, and many cohomological objects arising in enumerative geometry have K-theoretic analogues --- modular forms become Jacobi forms, Yangians become quantum affine algebras, etc. I will explain how this sort of refinement goes for vertex algebras. As an application, Joyce's recent "universal wall-crossing" machine, which operates by making the homology of certain moduli stacks into vertex algebras, can be lifted to equivariant K-theory, e.g. thereby proving the main conjecture on semistable invariants in refined Vafa–Witten theory. In a different direction, I expect there to be some hidden multiplicative vertex algebra structure on the aforementioned quantum affine algebras, which can be viewed as symmetry algebras controlling various enumerative and physical theories.

Link:
http://scgp.stonybrook.edu/video_portal/video.php?id=5434

Workshop:
Simons- Special Holonomy in Geometry, Analysis, and Physics: Progress and Open Problems