## シンポジウム・ワークショップ

### International workshop “Foliated spaces, Tilings, Group actions 2022″（2022年12月17日（土），18日（日））

2022.11.23 Wed up
• Date: 17th and 18th December, 2022
• Place: Zoom meeting and Room R101 in Rarcadia (17th Dec.), Room F205 in Forest House (18th Dec.) Biwako-Kusatsu Campus, Ritsumeikan University Campus map.
• Registration for on-site participation: Please fill this form. The deadiline is 12th December.
• Registration for online participation: Please fill this form. The deadline is 15th December.
• The website of the workshop is here

### 2022年12月16日(金) — 18日(日)　ワークショップ

2022.08.22 Mon up
Workshop “2022 Japan-China International Conference on matrix theory with applications”

Date : December 16 (Friday)  – December 18 (Sunday), 2022

Place: Colloquium Room, West Wing Building 6F
Biwako Kusatsu Campus, Ritsumeikan University
Kusatsu City, Shiga, Japan
No. 9 Building in <http://www.ritsumei.ac.jp/campusmap/bkc/>

Holding form : Hybrid format
Chinese side will give a lecture only online

Please click the registration bar below to register the workshop
Note that the deadline of the registration is 15 December, 2022

 Registration Schedule Abstracts Pamphlet

Speakers :
—Plenary talks—
• Etsuo Segawa (Yokohama National University)
• Lee Jaeha (University of Tokyo)
• Michael Ng  (University of Hong Kong)
• Qing-Wen Wang (Shanghai University)
—General Talks—
• Michiya Mori(University of Tokyo)
• Shiho Oi (Niigata University)
• Tomohiro Hayase (Cluster inc.)
• Yoichi Udagawa (Ritsumeikan University)
• Toshikazu Abe (Ibaraki University)
• Ryo Takakura (Kyoto University)
• Zhi-Gang Jia (Jiangsu Normal University)
• Tie-Xiang Li (Southeast University)
• Kan He (Taiyuan University of Technology)
• Xiaomin Pan (Shanghai University)
• Jianzhou Liu (Xiangtan University)
• Bing Zheng (Lanzhou University)
• Guang-Jing Song (Weifang University)
• Jinchuan Hou (Taiyuan University of Technology)

Local organizing Committee :
• Hiroyuki Osaka (Ritsumeikan University)
• Yoichi Udagawa (Ritsumeikan University)
• Masaru Nagisa (Ritsumeikan University)

Scientific Organizing Committee :
• Zhuo-Heng He (Shanghai University)
• Takaaki Yamazaki (Toyo University)
• Yuki Seo (Osaka Education University)
• Hiromichi Ohno (Shinshu University)
• Gen Kimura (Shibaura Institute of Technology)
• Qing-Wen Wang (Shanghai University)
• Xue-Feng Duan (Guilin University of Electronic Science and Technology)

Sponsar by
• Department of Mathematical Sciences, Ritsumeikan University, Japan
• JSPS KAKENHI Grant Number JP20K03644
• International Research Center for Tensor and Matrix Theory (IRCTMT), Shanghai University, China.
• Guilin University of Electronic Technology , Guilin, China.

### Mini-symposium on Stochastic Geometric Mechanics (28/10/2021)

2021.10.15 Fri up
<< Mini-symposium on Stochastic Geometric Mechanics >>

タイトル： A stochastic variational principle for the compressible Navier-Stokes equation

タイトル： The Schrödinger problem in space-time domains

アブストラクト：

### 研究集会 Foliated spaces, tilings and group actions

2021.03.17 Wed up

This conference aims to share new ideas on foliated spaces, tilings, group actions and their interrelations. This conference is supported by JSPS Grant-in-Aid for Scientific Research 20K03620.

### Date and Place

• Date: 16th and 17th April, 2021
9:00-12:20 (British Standard Time),
10:00-13:20 (Central European Time),
17:00-21:20 (Japan Standard Time)
• Place: Zoom meeting
• Registration: Please make registration through this form to join this conference. (Deadline : 14th April)

### Speakers

• Jesús Álvarez López   (Santiago de Compostela University)
• Ramón Barral Lijó   (Ritsumeikan University)
• Alex Clark   (Queen Mary University of London)
• John Hunton   (Durham University)
• Olga Lukina   (Vienna University)
• Yasushi Nagai   (Open University)
• John Parker   (Durham University)
• James Walton   (Nottingham University)

TBA

### International workshop on Geometry of Foliated Spaces

2019.10.24 Thu up
 日時： ２０１９年１１月２９日（金）１３：３０～１２月１日（日）１２：００ 会場： 立命館大学 びわこ・くさつキャンパス ウェストウィング6階 談話会室 キャンパスへのアクセス キャンパスマップ キャンパスマップ（pdfファイル） 住所： 滋賀県草津市野路東１－１－１

プログラム

１１月２９日（金）
13:30-14:20 Hitoshi Moriyoshi (Nagoya Univ.)
Geometry on the space of equi-centro-affine curves

14:40-15:30 Ramón Barral Lijó (Ritsumeikan Univ.)
Distinguishing colorings

15:50-16:40 Jesús Antonio Álvarez López  (Univ. of Santiago de Compostela)
Haefliger’s cohomology and tautness for matchbox manifolds

17:00-17:30 Subaru Nomoto (Ritsumeikan Univ.)
Some hierarchy in frames on curves on 4-dimensional Euclidean space

19:00- 懇親会 於 いさり火 庵

１１月３０日（土）
9:00-9:50 Ryuma Orita (Tokyo Metropolitan Univ.)
Rigid fibers of spinning tops

10:10-11:00 Olga Lukina  (Univ. of Vienna)
Cantor actions and Galois groups

11:20-12:10 Ramón Barral Lijó  (Ritsumeikan Univ.)
Breaking symmetry

14:30-15:20 Naoki Kato (Chukyo Univ.)
Turbulizations of transversely affine foliations of codimension two

15:40-16:30 Noboru Ito (Univ. of Tokyo)
A categorified Vassiliev skein relation on Khovanov homology

16:50-17:20 Norihisa Takahashi (Ritsumeikan Univ.)
Dehn twist presentations of hyperelliptic periodic maps

１２月１日（日）
9:00-9:50 Olga Lukina  (Univ. of Vienna)
Stabilizers of points for Cantor group actions

10:00-10:50 Tetsuya Abe (Ritsumeikan Univ.)
On annulus presentations of knots

11:10-12:00 Jesús Antonio Álvarez López  (Univ. of Santiago de Compostela)
A distributional trace formula for foliated flows

※ プログラムは変更されることがありますのであらかじめご了承ください。

E-mail：hnozawa（at）fc.ritsumei.ac.jp

Nov. 29: Program changed.
Oct. 24: Page created. First-announcement.
アブストラクト

Hitoshi Moriyoshi (Nagoya Univ.)

Title: Geometry on the space of equi-centro-affine curves

Abstract: A curve $$c$$ on the Euclidean plane is called equi-centro-affine if it satisfies $$\mathrm{det} (c c’)=1$$. The space of all equi-centro-affine curves on plane turns out to be a manifold of infinite dimension, which admits an interesting action by the group of orientation-preserving diffeomorphisms on unit circle. In this talk, we exhibit invariant pre-symplectic forms on the infinite-dimensional manifold and momentum maps related to those forms, which are also involved with the celebrated Gelfand-Fuchs $$2$$-cocycle.

Ramón Barral Lijó (Ritsumeikan Univ.)

Title: Distinguishing colorings

Abstract: We will introduce the concepts or distinguishing and limit distinguishing colorings for graphs, as well as the corresponding indices. We will also present known results and bounds for these indices for different families of graphs.

Jesús Antonio Álvarez López  (Univ. of Santiago de Compostela)

Title: Haefliger’s cohomology and tautness for matchbox manifolds

Abstract: (joint work with Steven Hurder and Hiraku Nozawa) For a compact foliated space $$\mathfrak M$$ of dimension $$p$$, we introduce a cochain complex which combines the de~Rham complex along the leaves and the Alexander-Spanier complex in the transverse direction. This complex also has a filtration by differential spaces, giving rise to a version of the Leray spectral sequence $$(E_k^{u,v},d_k)$$ for $$\mathfrak M$$. The part $$E_2^{\cdot,p}$$ is a version of the Haefliger cohomology for $$\mathfrak M$$, which can be used to characterize a version of tautness like in the case of foliations on compact manifolds. In particular, all matchbox manifolds are taut in our sense.

Subaru Nomoto (Ritsumeikan Univ.)

Title: Some hierarchy in frames on curves on 4-dimensional Euclidean space

Abstract: Bishop introduced a frame on space curves different from the well known Frenet frame. It is characteristic that any regular space curve admit this frame. For curves on R^4, there are four different type of Bishop type frames including the Frenet frame and the Bishop frame. In this talk, we discuss the relation between these four types of frames from the viewpoints of geometric structures on normal bundle f curves and ordinary differential equations.

Ryuma Orita (Tokyo Metropolitan Univ.)

Title: Rigid fibers of spinning tops

Abstract: In the talk, we deal with fibers of classical Liouville integrable systems containing the Lagrangian top and the Kovalevskaya top. Especially, we find a non-displaceable fiber for each of them. To prove these results, we use the notion of superheaviness introduced by Entov and Polterovich. This is a joint work with Morimichi Kawasaki (RIMS).

Olga Lukina  (Univ. of Vienna)

Title: Cantor actions and Galois groups

Abstract: In this talk, we consider applications of dynamical invariants for Cantor group actions in Number theory, namely for the study of a certain type of representations of absolute Galois groups of number and function fields.

Ramón Barral Lijó (Ritsumeikan Univ.)

Title: Breaking symmetry

Abstract: We will contextualize the previous talk in the setting of the Gromov space of graphs, and will present some applications to other areas of mathematics.

Naoki Kato (Chukyo Univ.)

Title: Turbulizations of transversely affine foliations of codimension two

Abstract: In 1980, Seke gave a condition for turbulized foliations of codimension one transversely affine foliations to have transverse affine structures again. Recently, Mitsumatsu and Vogt defined the notion of turbulizations for higher codimensional foliations. In this talk, we give a condition for turbulized foliations of codimension two transversely affine foliations to have transverse affine structures again.

Noboru Ito (Univ. of Tokyo)

Title: A categorified Vassiliev skein relation on Khovanov homology

Abstract: This is a joint work with Jun Yoshida (The University of Tokyo). In this talk, we define a chain map that categorifies the operation “crossing change” on Khovanov homology using a canonical short exact sequence of a mapping cone at each crossing of a link diagram. The chain map is invariant under moves of singular knots. By the setting, taking graded Euler characteristics, a Vassiliev skein relation for a Jones polynomial is recovered.

Norihisa Takahashi  (Ritsumeikan Univ.)

Title: Dehn twist presentations of hyperelliptic periodic maps

Abstract: Ishizaka classified up to conjugation hyperelliptic periodic diffeomorphisms of surfaces and gave Dehn twist presentations in terms of Humphries generators. In this talk, we will give an explicit decomposition of surfaces into pentagonal fundamental domains of hyperelliptic periodic diffeomorphisms. As an application, we obtain the Dehn twist presentations of hyperelliptic periodic mapping classes, which are closely related to the ones obtained by Ishizaka.

Olga Lukina  (Univ. of Vienna)

Title: Stabilizers of points for Cantor group actions

Abstract: We study properties of stabilizers of points for Cantor group actions, such as the number of distinct stabilizers of points without holonomy, and the genericity of points with non-trivial holonomy in a measure-theoretical sense. We then apply our results to study the properties of invariant random subgroups, defined by such action. Joint work with Maik Groeger.

Tetsuya Abe (Ritsumeikan Univ.)

Title: On annulus presentations of knots

Abstract: In 2013, Jong, Omae, Takeuchi and I introduced the notion of annulus presentations of knots. In this talk, we discuss the following topics:

1. Why we are interested in annulus presentations of knots.
2. An obstruction to knots admitting annulus presentations in terms of the Jones polynomial.
3. Table of knots which admit annulus presentations up to 8 crossings.

This is joint work with Keiji Tagami. Note that Gen Suzuki (who is a student of Ritsumeikan University) partially made the table of knots which admit annulus presentations up to 8 crossings.

Jesús Antonio Álvarez López  (Univ. of Santiago de Compostela)

Title: A distributional trace formula for foliated flows

Abstract: Let $$\mathcal F$$ be a smooth codimension one foliation on a compact manifold $$M$$. A flow $$\phi^t$$ on $$M$$ is said to be foliated if it maps leaves to leaves. If moreover the closed orbits and preserved leaves are simple, then there are finitely many preserved leaves, which are compact, forming a compact subset $$M^0$$, and a precise description of the transverse structure of $$\mathcal F$$ can be given. A version of the reduced leafwise cohomology, $$\overline{H}I(\mathcal F)$$, is defined by using distributional leafwise differential forms conormal to $$M^0$$. The talk will be about our progress to define distributional traces of the induced action of $$\phi^t$$ on $$\overline{H}^rI(\mathcal F)$$, for every degree $$r$$, and to prove a corresponding Lefschetz trace formula involving the closed orbits and leaves preserved by $$\phi^t$$. The formula also involves a distributional version of the $$\eta$$-invariant of $$M^0$$, which might be zero. This kind of distributional trace formula was conjectured by Christopher Deninger, and it was proved by the first two authors when $$M^0=\emptyset$$.

### 2019年10月15日(火) ワークショップ

2019.09.26 Thu up
”Ritsumeikan One Day Workshop on Probability and Statistics”

### 2019年5月25日(土)・26日(日) 研究集会「幾何学と力学とその応用」

2019.05.05 Sun up

(Geometry, Mechanics, and their Applications）

ウェストウィング 6階談話会室

プログラムPDFファイルをご覧ください）

### 2019年9月1日(日)～7日(土)　ワークショップ

2019.04.05 Fri up
The Fifth Japan-China Geometry Conference

Dates: September 1–September 7, 2019
Conference Venue: Ritsumeikan University,  Biwako-Kusatsu Campus (BKC), West-Wing

Organizers:

Scientific Committee:
Akito Futaki (Tsinghua University)
Anmin Li (Sichuan University)
Toshiki Mabuchi (Osaka University)
Yoshihiro Ohnita (Osaka City University)
Gang Tian (Peking University)
Weiping Zhang (Chern Institute of Mathematics)

Organizing Committee:
Qing-Ming Cheng (Fukuoka University)
Qing Ding (Fudan University)
Ryushi Goto (Osaka University)
Ryoichi Kobayashi (Nagoya University)
Haizhong Li (Tsinghua University)
Jiayu Li (University of Science and Technology of China)
Reiko Miyaoka (Tohoku University)
Hitoshi Moriyoshi (Nagoya University)
Takashi Shioya (Tohoku University)
Zizhou Tang (Chern Institute of Mathematics)
Changping Wang (Fujian Normal University)

Local Organizers:
Hiroyuki Osaka (Ritsumeikan University)
Toshikazu Natsume (Ritsumeikan University)

Invited Speakers:
Daguang Chen (Tsinghua University)

Fuquan Fang (Capital Normal University)
Atsushi Fujioka (Kansai University)
Pengfei Guan (McGill University)
Xiaoli Han (Tsinghua University)
Shohei Honda (Tohoku University)
Rongli Huang (Guangxi Normal University)
Masashi Ishida (Tohoku University)
Xiaoshang Jin (Peking University)
Haizhong Li (Tsinghua University)
Toshiki Mabuchi (Osaka University)
Shin-ichi Ohta  (Osaka University)
Kaoru Ono (Kyoto University)
Chao Qian (Beijing Institute of Technology)
Li Sheng (Sichuan University)
Gang Tian (Peking University)
Peng Wang  (Fujian Normal University)
Yong Wei (University of Science and Technology of  China and Australian National University)
Hongwei Xu (Zhejiang University)
Takao Yamaguchi (Kyoto University)
Xi Zhang (University of Science and Technology of China)

For information:
Q.-M. Cheng  (cheng@fukuoka-u.ac.jp)
R. Miyaoka (r-miyaok@m.tohoku.ac.jp)
H. Moriyoshi (moriyosi@math.nagoya-u.ac.jp)

Supported by :
JSPS Grants (Q.-M. Cheng, R. Goto, R. Miyaoka, H. Moriyoshi, T. Shioya), and
Department of Mathematical Science, Ritsumeikan University

### 2019年4月4日(木)　ワークショップ

2019.04.01 Mon up
”One day workshop on stochastic analysis”
• Date: 4 Apr. (Thu.)
• Place: W.W. 6th-floor, Colloquium Room
• Time: 13:00-18:20

Schedule

• Time: 13:00-13:40
• Speaker: Seiichiro Kusuoka (Okayama University)
• Title: Invariant measure and flow associated to the Phi4-quantum field model on the three-dimensional torus

• Time: 13:45-14:25
• Speaker: David Nualart (Kansas University)
• Title: Breuer-Major theorem: tightness and rate of convergence

• Time: 14:40-15:20
• Speaker: Hiroshi Tsukada (Kyoto University)
• Title: Pathwise uniqueness of SDEs driven by strictly stable processes

• Time: 15:25-15:45
• Speaker: Takuya Nakagawa (Ritsumeikan University)
• Title: $L^{\beta}$ distance between two one-dimensional stochastic differential equations driven by a symmetric $\alpha$-stable process

• Time: 16:00-16:40
• Speaker: Lorick Huang (INSA de Toulouse)
• Title: A Local Limit Theorem for Robbins-Monro Procedure

• Time: 16:45-17:25
• Speaker: Yu Ito (Kyoto Sangyo University)
• Title: A fractional calculus approach to rough path integration

• Time: 17:40-18:20
• Speaker: Anthony Reveillac (INSA de Toulouse)
• Title: On a stochastic Hardy-Littlewood-Sobolev inequality with application to Strichartz estimates for a noise dispersion

Organizing Committee: Yuuki Ida (Ritsumeikan University) and Gô Yûki (Ritsumeikan University)

### 2018年10月18日(木)　ワークショップ

2018.10.18 Thu up
”Ritsumeikan Workshop on Probability Theory and its Applications to Insurance and Finance”