過去の記録

数理科学研究科の活動

2024年02月05日(月)

応用解析セミナー

16:00-17:30 数理科学研究科棟(駒場) 122号室
対面・オンラインハイブリッド開催（通常と開催曜日・会場が異なりますのでご注意ください）
Reinhard Farwig 氏 (Technische Universität Darmstadt)
Viscous Flow in Domains with Moving Boundaries - From Bounded to Unbounded Domains (English)

[ 講演概要 ]
以下のPDFファイルをご参照ください：
https://drive.google.com/file/d/1dJJU1ybE-n8yn3LZTReTeH2UFX9wXQv9/view?usp=drive_link

[ 参考URL ]
https://forms.gle/xKPKu1uw9PeHEEck9

東京確率論セミナー

17:00-18:30 数理科学研究科棟(駒場) 126号室
16:15から２階のコモンルームでTea timeを行いますので、ぜひそちらにもご参加ください。
Sunder Sethuraman 氏 (University of Arizona)
Atypical behaviors of a tagged particle in asymmetric simple exclusion (English)

[ 講演概要 ]
Informally, the one dimensional asymmetric simple exclusion process follows a collection of continuous time random walks on Z interacting as follows: When a clock rings, the particle jumps to the nearest right or left with probabilities p or q=1-p, if that location is unoccupied. If occupied, the jump is suppressed and clocks start again.

In this system, seen as a toy model of `traffic', the motion of a distinguished or `tagged' particle is of interest. Starting from a stationary state, we study the `typical' behavior of a tagged particle, conditioned to deviate to an `atypical' position at time Nt, for a t>0 fixed. In the course of results, an `upper tail' large deviation principle, in scale N, is established for the position of the tagged particle. Also, with respect to `lower tail' events, in the totally asymmetric version, a connection is made with a `nonentropy' solution of the associated hydrodynamic Burgers equation. This is work with S.R.S. Varadhan (arXiv:2311.0780).

2024年01月30日(火)

日仏数学拠点FJ-LMIセミナー

16:30-17:30 数理科学研究科棟(駒場) 号室
Danielle HILHORST 氏 (CNRS, Université de Paris-Saclay, France)
Convergence of solutions of a one-phase Stefan problem with Neumann boundary data to a self-similar profile. (英語)

[ 講演概要 ]
We study a one-dimensional one-phase Stefan problem with a Neumann boundary condition on the fixed part of the boundary.
We construct a unique self-similar solution and show that for a large class of initial data, the solution of the time evolution problem
converges to this self-similar solution as time tends to infinity. Similar results were already obtained by Bouguezzi, Hilhorst,
Miyamoto, and Scheid in the case of Dirichlet data on the fixed boundary. However, they had to show that the space derivative
of the solution uniformly converges to its limit. Here, our proof requires less regularity, which should make our arguments easier
to adapt to different settings.

This is a joint work with Sabrina Roscani and Piotr Rybka.

[ 参考URL ]
https://fj-lmi.cnrs.fr/seminars/

応用解析セミナー

16:30-17:30 数理科学研究科棟(駒場) 002号室
対面（通常と開催曜日・会場が異なりますのでご注意ください）
Danielle Hilhorst 氏 (CNRS / Université de Paris-Saclay)
Convergence of solutions of a one-phase Stefan problem with Neumann boundary data to a self-similar profile. (English)

[ 講演概要 ]
We study a one-dimensional one-phase Stefan problem with a Neumann boundary condition on the fixed part of the boundary.
We construct a unique self-similar solution and show that for a large class of initial data, the solution of the time evolution problem converges to this self-similar solution as time tends to infinity. Similar results were already obtained by Bouguezzi, Hilhorst, Miyamoto, and Scheid in the case of Dirichlet data on the fixed boundary. However, they had to show that the space derivative of the solution uniformly converges to its limit. Here, our proof requires less regularity, which should make our arguments easier to adapt to different settings.
This is a joint work with Sabrina Roscani and Piotr Rybka.