Math Seminars by Dr. Genki Ouchi and Dr. Kenta Sato
 Date
 September 24 (Thu) at 16:00  18:10, 2020 (JST)
 Speakers

 Dr. Genki Ouchi (Special Postdoctoral Researcher, iTHEMS)
 Dr. Kenta Sato (Special Postdoctoral Researcher, iTHEMS)
 Venue
 via Zoom
 Language
 English
[Talk 1] (16:00  17:00) Dr. Genki Ouchi
Automorphism groups of cubic fourfolds and K3 categories
In this talk, I would like to talk about symmetries of algebraic varieties, especially cubic fourfolds and K3 surfaces. It is known that symmetries of cubic fourfolds and K3 surfaces are related to sporadic finite groups as Mathieu groups and Conway groups in both algebraic geometry and string theory. Relations between cubic fourfolds and K3 surfaces are studied in the context of derived categories, Hodge theory and so on. I would like to explain the direct relation among symmetries of cubic fourfolds and K3 surfaces via their derived categories.
[Talk 2] (17:10  18:10) Dr. Kenta Sato
An algebraic approach to the four color theorem
The four color theorem states that, given any separation of a plane into contiguous regions, no more than four colors are required to color the regions. Although this theorem was already proved about 40 years ago, another proof without using a computer is not found still now.
In this talk, I will introduce an algebraic approach to this theorem, which states that a conjecture about singularities of algebraic varieties implies the four color theorem. In particular, I would like to focus on the connection of three different fields in mathematics: graph theory, convex geometry and algebraic geometry.
*Detailed information about the seminar refer to the email.