Geometric Perspective for the Theory of Hydrodynamic Limits
 Date
 August 31 (Mon) at 13:00  September 1 (Tue) at 15:00, 2020 (JST)
 Speakers

 Makiko Sasada
 Kenichi Bannai (Professor, Faculty of Science and Technology Department of Mathematics, Keio University)
 Venue
 via Zoom
 Language
 English
This is a series of lectures on "Geometric Perspectives for Fluid Dynamic Limit Theory" by the following speakers:
[DAY 1: Aug 31] Dr. Makiko Sasada (University of Tokyo)
[DAY 2: Sept 1] Prof. Kenichi Bannai (Keio University)
Abstract:
One of the fundamental problems in the natural and social sciences is to explain macroscopic phenomena that we can observe from the rules governing the microscopic system giving rise to the phenomena. Hydrodynamic limit provides a rigorous mathematical method to derive the deterministic partial differential equations describing the time evolution of macroscopic parameters, from the stochastic dynamics of a microscopic large scale interacting system.
In the article "Topological Structures of Large Scale Interacting Systems via Uniform Locality" joint with Yukio Kametani, we introduce a general framework encompassing a wide variety of interacting systems in order to systematically investigate various microscopic stochastic large scale interacting systems in a unified fashion. In particular, we introduced a new cohomology theory called the uniformly local cohomology to investigate the underlying geometry of the interacting system. Our theory gives a new interpretation of the macroscopic parameters, the role played by the group action on the microscopic system, and the origin of the diffusion matrix associated to the macroscopic deterministic partial differential equation obtained via the spacetime scaling limit of the microscopic system.
The purpose of the series of lectures is to introduce to the audience the theory of hydrodynamic limits, especially the relation between the macroscopic observables and the microscopic interacting system. We then explain our new perspective of how geometry comes into play in investigating the interacting system, and introduce the ideas and results of our article.
*Detailed information about the seminar refer to the email.