セミナー

2017年6月16日(金) 立命館大学幾何学セミナー

2017.06.13 Tue up
日時: 2017年6月16日(金) 15:00~17:15
場所: 立命館大学びわこ・くさつキャンパス(BKC) ウェストウィング6階 談話会室

講演①(15:00~16:00)
タイトル:Heidenberg 群上の(Sub-)Laplacian に対する熱核の展開公式とその応用

講演者:岩崎千里 (兵庫県立大学)

アブストラクト:
Heisenberg 群上のLaplacian およびSub-Laplacian に対する熱方程式の基本解をワイル表象を使って擬微分作用素として書き表すことにより,固有関数展開の手法が適用できることを示す.
この結果をHeisenberg 群上のform に作用するLaplacian の基本解の表示に応用する.

講演②(16:15~17:15)
タイトル:Band rearrangement against a control parameter through Dirac equations with boundary conditions

講演者:岩井敏洋 (京都大学)

アブストラクト:
An elementary band rearrangement or energy level redistribution takes place between two adjacent bands and any band rearrangement can be regarded as composed of elementary ones.
Band rearrangement can be viewed as a global topological change which is a collection of local contributions observed at critical points.
The local topological change can be detected by the linearization method applied at each critical point.
Dirac equations show up in this context as linear equations for the study of elementary band rearrangements.

The Dirac equations of space-dimension one, two, and three are studied under both the APS (Atiyah-Patodi-Singer) and the chiral bag boundary conditions, where bounded domains are an interval, a disk, and a ball, respectively, and where mass is treated as a parameter ranging over all real numbers.
Discrete symmetry of the boundary condition and the Hamiltonian are discussed to explain the symmetry observed in the pattern of change in eigenvalues against the parameter.
Related topics will be touched upon, including topological insulator in quantum physics.
This talk is based on joint works with B. Zhilinskii at Université du Littoral Côte d’Opale.

Math-Fi seminar on 16 Jun.

2017.06.12 Mon up
  • Date: 16 June (Fri.)
  • Place: W.W. 7th-floor, 4th lab.
  • Time: 16:30-18:00
  • Speaker: Toshiki Okumura (The Dai-ichi Life insurance Company, Limited)
  • Title: On a construction of strong solutions for stochastic differential equations with non-Lipschitz coefficients; a priori estimates approach
  • Abstract: Given a stochastic differential equation of which coefficients satisfy Yamada-Watanabe condition or Nakao-Le Gall condition. We prove that its strong solution can be constructed on any probability space using a priori estimates and also using Ito theory based on Picard’s approximation scheme. 
 

Math-Fi seminar on 8 Jun.

2017.06.06 Tue up
  • Date: 8 June (Thu)
  • Place: W.W. 6th-floor, Colloquium Room
  • Time: 16:30-18:00
  • Speaker: Jiro Akahori (Ritsumeikan univ.)
  • Title: TBA

Math-Fi seminar on 19 May

2017.05.18 Thu up
  • Date: 19 May (Fri)
  • Place: W.W. 6th-floor, Colloquium Room
  • Time: 16:30-18:00
  • Speaker: Hideo Nagai (Kansai univ.)
  • Title: Large deviation control arising from downside riskminimization against a benchmark
  • abstract

Math-Fi seminar on 11 May

2017.05.10 Wed up
  • Date: 11 May (Thu.)
  • Place: W.W. 6th-floor, Colloquium Room
  • Time: 16:30-18:00
  • Speaker: Tatsuki Akiyama, Arturo Kohatsu-Higa and Takuya Nakagawa
 

Math-Fi seminar on 20 Apr.

2017.04.18 Tue up
  • Date: 20 Apr. (Thu.)
  • Place: W.W. 6th-floor, Colloquium Room
  • Time: 16:30-18:00
  • Speaker: Kazuhiro Yoshikawa (Ritsumeikan univ.)
  • Title: TBA
 

Math-Fi seminar on 13 Apr.

2017.04.13 Thu up
  • Date: 13 Apr. (Thu.)
  • Place: W.W. 6th-floor, Colloquium Room
  • Time: 16:30-18:00
  • Speaker: Keita Owari (Ritsumeikan univ.)
  • Title: A Komlós-Type Result in Dual Orlicz Spaces
≫ 続きを読む

2017年4月28日(金) 立命館大学幾何学セミナー

2017.04.07 Fri up
講演者: 池田憲明 (立命館大学)
タイトル: ポアソン幾何と魔法の公式
日時: 2017年4月28日(金) 16:30~18:00
場所: 立命館大学びわこ・くさつキャンパス(BKC) ウェストウィング6階 談話会室
概要:
ポアソン幾何学は物理理論、量子化、微分幾何学、ホモトピー代数、トポロジー、力学系などの分野にまたがる普遍的な数学構造を「ポアソン括弧」にもとづいて理解し解析しようとする比較的新しい数学の分野である。このセミナーでは、微分幾何学の基本的な公式である「カルタンの魔法の公式」を使ってポアソン幾何の考え方を説明したい。最後に自身の最近の研究結果である弦理論におけるT双対への応用を説明する。

Math-Fi seminar on 6 Apr.

2017.04.05 Wed up
  • Date: 6 Apr. (Thu.)
  • Place: W.W. 6th-floor, Colloquium Room
  • Time: 16:30-18:00
  • Speaker: Tomonori Nakatsu(Ritsumeikan univ.)
  • Title: Some properties of density function on maxima of one-dimensional diffusion processes.
≫ 続きを読む

Math-Fi seminar on 16 Mar.

2017.03.13 Mon up
Date : 16 Mar. (Thu.)
Place: W.W. 6th-floor, Colloquium Room
Time : 16:30-18:00
Speaker: Tomooki Yuasa (Ritsumeikan university)
Title: Importance sampling for parametrix simulation method