Square root Euler classes and counting sheaves on Calabi-Yau 4-folds
Richard Thomas (Imperial College London)
Abstract: I will explain a nice characteristic class of $SO(2n,\mathbf{C})$ bundles in both Chow cohomology and K-theory, and how to localise it to the zeros of an isotropic section. This builds on work of Edidin-Graham, Polishchuk-Vaintrob, Anderson and many others.
This can be used to construct an algebraic virtual cycle (and virtual structure sheaf) on moduli spaces of stable sheaves on Calabi-Yau 4-folds. It recovers the real derived differential geometry virtual cycle of Borisov-Joyce but has nicer properties, like a torus localisation formula. Joint work with Jeongseok Oh (KIAS).
algebraic geometry
Audience: researchers in the topic
Comments: The discussion for Richard Thomas’s talk is taking place not in zoom-chat, but at tinyurl.com/2020-09-25-rt (and will be deleted after 3-7 days).
Stanford algebraic geometry seminar
Series comments: The seminar was online for a significant period of time, but for now is solely in person. More seminar information (including slides and videos, when available): agstanford.com
| Organizer: | Ravi Vakil* |
| *contact for this listing |