MS Seminar (Mathematics - String Theory)

Speaker: Yaping Yang (University of Melbourne)
Title: Cohomological Hall algebras and perverse coherent sheaves on toric Calabi-Yau 3-folds
Date (JST): Thu, Feb 09, 2023, 13:30 - 15:00
Place: Hybrid
Abstract: I will start with the moduli space of perverse coherent sheaves on a toric Calabi-Yau 3-fold X. I will then talk about the action of the cohomological Hall algebra (COHA) of Kontsevich and Soibelman on its cohomology via “raising operators”. I will also discuss the “double” of the COHA that acts on the cohomology by adding the “lowering operators”. We associate a root system to X. The double COHA is expected to be the shifted Yangian of this root system and the shift is given by an intersection pairing. I will mention other interesting structures (e.g., the VOA structure) obtained from the action of the double COHA. This is based on my joint work with M. Rapcak, Y. Soibelman, and G. Zhao.