MS Seminar (Mathematics - String Theory)

Speaker: Timothy Logvinenko (Cardiff University)
Title: The Hochschild homology of a non-commutative symmetric quotient stack
Date (JST): Thu, Apr 10, 2025, 13:30 - 15:00
Place: Seminar Room B
Abstract: Let $X$ be a smooth, quasi-projective complex variety with an action of a finite group $G$. In arXiv:math/0206256 Baranovsky gave a decomposition of the complex cohomology of the stack $[X/G]$ in terms of the cohomologies of the fixed point loci $X_g$ for $g \in G$. He constructed this decomposition for the Hochschild homology of $[X/G]$ which is isomorphic to the complex cohomology via the Hochschild-Kostant-Rosenberg isomorphism.

It is natural to ask if a similar decomposition exists for non-commutative varieties. I will talk about the specific case where the permutation group $S_n$ acts on the $n$-th tensor power $V^{\otimes n}$ of a DG category V.