杉本代数セミナー
Sugimoto Algebra Seminar
Sugimoto Algebra Seminar
We meet on Friday at 16:00 on Sugimoto Campus of Osaka Metropolitan University.
The venue is Room E408 in Science Building E. We also broadcast the seminar via Zoom.
Organizers: Yohsuke Matsuzawa, Ryo Kanda, Takamichi Sano, Hiroyuki Minamoto
Monday, January 26, 2026, 16:00-17:00
Venue: Room F415 in Science Building F
Yasuaki Ogawa (Kansai University)
Title: On a dg quotient of exact dg categories
Abstract: Under the Yoneda embedding, a category $\C$ loses its exact structure and becomes a split exact category of projective objects. The lost exact structure can be recovered by passing to appropriate Serre (or Verdier) quotients. For $Mod\C$, the Quillen embedding realizes $\C$ as an extension-closed subcategory inside the Serre quotient by defect objects, whereas Neeman’s derived categories arise from a different, though philosophically related, quotient construction. These conceptually different phenomena can be described in a unified framework via Chen’s universal embedding for exact dg categories. In this talk, we demonstrate some applications of the universal embedding. In particular, a certain extriangulated quotient, which is a generalization of the Verdier quotient, is enhanced by a Drinfeld dg quotient. Some parts of this talk are based on joint work with Nao Mochizuki and Amit Shah.
Sugimoto Algebra Seminars are supported by:
JSPS KAKENHI Grant Number JP24K06693
Osaka Central Advanced Mathematical Institute (MEXT Promotion of Distinctive Joint Research Center Program JPMXP0723833165), Osaka Metropolitan University