Tokyo-Nagoya Algebra Seminar

Seminar information archive ~05/21Next seminarFuture seminars 05/22~

Organizer(s) Noriyuki Abe, Aaron Chan, Osamu Iyama, Yasuaki Gyoda, Hiroyuki Nakaoka, Ryo Takahashi

2025/05/07

13:00-14:30   Online
Sebastian Opper (Universeity of Tokyo)
Autoequivalences of triangulated categories via Hochschild cohomology (English)
[ Abstract ]
I will talk about a general tool which allows one to study symmetries of (enhanced) triangulated categories in the form of their derived Picard groups. In general, these groups are rather elusive to computations which require a rather good understanding of the category at hand. A result of Keller shows that the Lie algebra of the derived Picard group of an algebra can be identified with its Hochschild cohomology equipped with the Gerstenhaber Lie bracket. Mimicking the classical relationship between Lie groups and their Lie algebras, I will explain how to "integrate" elements in the Hochschild cohomology of a dg category over fields of characteristic zero to elements in the derived Picard group via a generalized exponential map. Afterwards we discuss properties of this exponential and a few applications. This includes necessary conditions for the uniqueness of enhancements of triangulated functors and uniqueness of Fourier-Mukai kernels. Other applications concern derived Picard groups of categories arising in algebra and geometry: derived categories of graded gentle algebras and their corresponding partially wrapped Fukaya categories or stacky nodal curves as well as Fukaya categories of cotangent bundles and their plumbings.

Zoom ID 822 3531 1702 Password 596657
[ Reference URL ]
https://www.math.nagoya-u.ac.jp/~aaron.chan/TNAseminar.html