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: This seminar requires both advance registration, and a password. Register at stanford.zoom.us/meeting/register/tJEvcOuprz8vHtbL2_TTgZzr-_UhGvnr1EGv Password: 362880
If you have registered once, you are always registered for the seminar, and can join any future talk using the link you receive by email. If you lose the link, feel free to reregister. This might work too: stanford.zoom.us/j/95272114542
More seminar information (including slides and videos, when available): agstanford.com
Organizer: | Ravi Vakil* |
*contact for this listing |