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Seminar information archive
Seminar information archive ～11/18｜Today's seminar 11/19 | Future seminars 11/20～
Tokyo-Nagoya Algebra Seminar
16:30-18:00 Online
Toshiya Yurikusa (Osaka Metropolitan University)
Finiteness and tameness of Jacobian algebras (Japanese)
https://www.math.nagoya-u.ac.jp/~aaron.chan/TNAseminar.html
Toshiya Yurikusa (Osaka Metropolitan University)
Finiteness and tameness of Jacobian algebras (Japanese)
[ Abstract ]
本講演では、有限次元ヤコビ代数をその表現型の観点から研究し、$E$不変量によって定義される$E$有限性および$E$-tame性と、$g$有限性、$\tau$傾有限性、表現有限性などの他の有限性・tame性の概念との対応について述べる。
まず、これらの性質がクイバーとポテンシャルの変異の下で不変であることを示す。その結果として、有限次元ヤコビ代数$\mathcal{J}(Q,W)$が$E$有限であることは、$g$有限、$\tau$傾有限、表現有限であることと同値であり、この場合には $Q$がDynkin型であることが分かる。この結果は、Demonetの「$E$有限なら$g$有限である」という予想を含む形で成立している。
また、$E$-tame性に関しては、例外的な3つの型を除いて、$g$-tame性および表現tame性と対応することが分かる。本講演は、Mohamad Haerizadeh氏との共同研究に基づくものである。
Zoom ID 829 2845 2592
Password 265160
[ Reference URL ]本講演では、有限次元ヤコビ代数をその表現型の観点から研究し、$E$不変量によって定義される$E$有限性および$E$-tame性と、$g$有限性、$\tau$傾有限性、表現有限性などの他の有限性・tame性の概念との対応について述べる。
まず、これらの性質がクイバーとポテンシャルの変異の下で不変であることを示す。その結果として、有限次元ヤコビ代数$\mathcal{J}(Q,W)$が$E$有限であることは、$g$有限、$\tau$傾有限、表現有限であることと同値であり、この場合には $Q$がDynkin型であることが分かる。この結果は、Demonetの「$E$有限なら$g$有限である」という予想を含む形で成立している。
また、$E$-tame性に関しては、例外的な3つの型を除いて、$g$-tame性および表現tame性と対応することが分かる。本講演は、Mohamad Haerizadeh氏との共同研究に基づくものである。
Zoom ID 829 2845 2592
Password 265160
https://www.math.nagoya-u.ac.jp/~aaron.chan/TNAseminar.html
2025/10/17
Colloquium
15:30-16:30 Room #NISSAY Lecture Hall (大講義室) (Graduate School of Math. Sci. Bldg.)
Kenichi Bannai (Keio University/RIKEN)
Building Inclusive Educational and Research Environments
—Current Situations and Responsibilities—
(日本語)
Kenichi Bannai (Keio University/RIKEN)
Building Inclusive Educational and Research Environments
—Current Situations and Responsibilities—
(日本語)
[ Abstract ]
The speaker has been engaged in artificial intelligence and machine learning research at the RIKEN Center for Advanced Intelligence Project for about ten years, collaborating with researchers from diverse fields. From 2020 to 2024, through serving as a member and later chair of the Gender Equality Committee of the Mathematical Society of Japan, the speaker also became more deeply aware of broader social issues in academia.
Creating inclusive educational and research environments where members from diverse backgrounds can thrive is essential for fostering a vibrant research community. This lecture, together with a panel discussion, aims to provide an opportunity to reflect on current challenges, explore the responsibilities of individuals and institutions, and discuss possible directions toward building better environments.
The speaker has been engaged in artificial intelligence and machine learning research at the RIKEN Center for Advanced Intelligence Project for about ten years, collaborating with researchers from diverse fields. From 2020 to 2024, through serving as a member and later chair of the Gender Equality Committee of the Mathematical Society of Japan, the speaker also became more deeply aware of broader social issues in academia.
Creating inclusive educational and research environments where members from diverse backgrounds can thrive is essential for fostering a vibrant research community. This lecture, together with a panel discussion, aims to provide an opportunity to reflect on current challenges, explore the responsibilities of individuals and institutions, and discuss possible directions toward building better environments.
2025/10/14
Operator Algebra Seminars
16:45-18:15 Room #126 (Graduate School of Math. Sci. Bldg.)
Frank Taipe (IMCA)
Compact quantum ergodic systems arising from planar algebras
[ Reference URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm
Frank Taipe (IMCA)
Compact quantum ergodic systems arising from planar algebras
[ Reference URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm
Tuesday Seminar on Topology
17:00-18:30 Room #056 (Graduate School of Math. Sci. Bldg.)
Pre-registration required. See our seminar webpage.
Keiji Oguiso (The University of Tokyo)
On K3 surfaces with non-elementary hyperbolic automorphism group (JAPANESE)
https://park.itc.u-tokyo.ac.jp/MSF/topology/TuesdaySeminar/index_e.html
Pre-registration required. See our seminar webpage.
Keiji Oguiso (The University of Tokyo)
On K3 surfaces with non-elementary hyperbolic automorphism group (JAPANESE)
[ Abstract ]
This talk is based on my joint work with Professor Koji Fujiwara (Kyoto University) and Professor Xun Yu (Tianjin University).
Main result of this talk is the finiteness of the Néron-Severi lattices of complex projective K3 surfaces whose automorphism groups are non-elementary hyperbolic, under the assumption that the Picard number greater than or equal to 6 (which is optimal to ensure the finiteness). In this talk, after recalling basic facts and some special nice properties of K3 surfaces, the notion of hyperbolicity of group due to Gromov, and their importance and interest (in our view), I would like to explain first why the non-elementary hyperbolicity of K3 surface automorphism group is the problem of the Néron-Severi lattices and then how one can deduce the above-mentioned finiteness, via a recent important observation by Professors Kikuta and Takatsu (independently) on geometrically finiteness, with a new algebro-geometric study of genus one fibrations on K3 surfaces by us.
[ Reference URL ]This talk is based on my joint work with Professor Koji Fujiwara (Kyoto University) and Professor Xun Yu (Tianjin University).
Main result of this talk is the finiteness of the Néron-Severi lattices of complex projective K3 surfaces whose automorphism groups are non-elementary hyperbolic, under the assumption that the Picard number greater than or equal to 6 (which is optimal to ensure the finiteness). In this talk, after recalling basic facts and some special nice properties of K3 surfaces, the notion of hyperbolicity of group due to Gromov, and their importance and interest (in our view), I would like to explain first why the non-elementary hyperbolicity of K3 surface automorphism group is the problem of the Néron-Severi lattices and then how one can deduce the above-mentioned finiteness, via a recent important observation by Professors Kikuta and Takatsu (independently) on geometrically finiteness, with a new algebro-geometric study of genus one fibrations on K3 surfaces by us.
https://park.itc.u-tokyo.ac.jp/MSF/topology/TuesdaySeminar/index_e.html
Tuesday Seminar of Analysis
16:00-17:30 Room #002 (Graduate School of Math. Sci. Bldg.)
Takashi KAGAYA (Muroran Institute of Technology)
Inverse curvature flow of Legendre curves (Japanese)
Takashi KAGAYA (Muroran Institute of Technology)
Inverse curvature flow of Legendre curves (Japanese)
2025/10/10
Algebraic Geometry Seminar
10:00-11:30 Room #122 (Graduate School of Math. Sci. Bldg.)
Yuri Tschinkel (New York University)
Equivariant birational geometry
Yuri Tschinkel (New York University)
Equivariant birational geometry
[ Abstract ]
I will report on new results and constructions in higher-dimensional birational geometry in presence of actions of finite groups.
I will report on new results and constructions in higher-dimensional birational geometry in presence of actions of finite groups.
2025/10/08
Geometric Analysis Seminar
10:30-11:30 Room #126 (Graduate School of Math. Sci. Bldg.)
Jinpeng Lu (University of Helsinki)
Quantitative stability of Gel'fand's inverse problem (英語)
https://www.mv.helsinki.fi/home/jinpeng/
Jinpeng Lu (University of Helsinki)
Quantitative stability of Gel'fand's inverse problem (英語)
[ Abstract ]
Inverse problems study the determination of the global structure of a space or coefficients of a system from local measurements of solutions to the system. The problems are originally motivated from imaging sciences, where the goal is to deduce the structure of the inaccessible interior of a body from measurements at the exterior. A fundamental inverse problem, Gel'fand's inverse problem, asks to determine the geometry of a Riemannian manifold from local measurements of the heat kernel. In this talk, I will explain how the unique solvability of the classical Gel'fand's inverse problem can be established on manifolds via Tataru's optimal unique continuation theorem for the wave operator. Next, I will discuss our recent works on the uniqueness and stability of the inverse problem for the Gromov-Hausdorff limits of Riemannian manifolds with bounded sectional curvature. This talk is based on joint works with Y. Kurylev, M. Lassas, and T. Yamaguchi.
[ Reference URL ]Inverse problems study the determination of the global structure of a space or coefficients of a system from local measurements of solutions to the system. The problems are originally motivated from imaging sciences, where the goal is to deduce the structure of the inaccessible interior of a body from measurements at the exterior. A fundamental inverse problem, Gel'fand's inverse problem, asks to determine the geometry of a Riemannian manifold from local measurements of the heat kernel. In this talk, I will explain how the unique solvability of the classical Gel'fand's inverse problem can be established on manifolds via Tataru's optimal unique continuation theorem for the wave operator. Next, I will discuss our recent works on the uniqueness and stability of the inverse problem for the Gromov-Hausdorff limits of Riemannian manifolds with bounded sectional curvature. This talk is based on joint works with Y. Kurylev, M. Lassas, and T. Yamaguchi.
https://www.mv.helsinki.fi/home/jinpeng/
FJ-LMI Seminar
15:00-16:00 Room #056 (Graduate School of Math. Sci. Bldg.)
Sourav Ghosh (Ashoka University)
Proper actions on group manifolds (英語)
Sourav Ghosh (Ashoka University)
Proper actions on group manifolds (英語)
[ Abstract ]
In this talk, I will show how to use known examples of flat affine manifolds to obtain new examples of proper actions of discrete groups on group manifolds. This is a joint work with Toshiyuki Kobayashi.
In this talk, I will show how to use known examples of flat affine manifolds to obtain new examples of proper actions of discrete groups on group manifolds. This is a joint work with Toshiyuki Kobayashi.
2025/10/07
Tuesday Seminar on Topology
17:00-18:00 Online
Pre-registration required. See our seminar webpage.
Sakumi Sugawara (Hokkaido University)
Topology of hyperplane arrangements and related 3-manifolds (JAPANESE)
https://park.itc.u-tokyo.ac.jp/MSF/topology/TuesdaySeminar/index_e.html
Pre-registration required. See our seminar webpage.
Sakumi Sugawara (Hokkaido University)
Topology of hyperplane arrangements and related 3-manifolds (JAPANESE)
[ Abstract ]
One of the central questions in the topology of hyperplane arrangements is whether several topological invariants are combinatorially determined. While the cohomology ring of the complement has a combinatorial description, it remains open whether even the first Betti number of the Milnor fiber is. In contrast, the homeomorphism types of 3-manifolds appearing as the boundary manifold of projective line arrangements and the Milnor fiber boundary of arrangements in a 3-dimensional space are combinatorially determined. In this talk, we focus on these 3-manifolds. In particular, we will present the cohomology ring structure for the boundary manifold, originally due to Cohen-Suciu, and an explicit formula for the homology group of the Milnor fiber boundary of generic arrangements.
[ Reference URL ]One of the central questions in the topology of hyperplane arrangements is whether several topological invariants are combinatorially determined. While the cohomology ring of the complement has a combinatorial description, it remains open whether even the first Betti number of the Milnor fiber is. In contrast, the homeomorphism types of 3-manifolds appearing as the boundary manifold of projective line arrangements and the Milnor fiber boundary of arrangements in a 3-dimensional space are combinatorially determined. In this talk, we focus on these 3-manifolds. In particular, we will present the cohomology ring structure for the boundary manifold, originally due to Cohen-Suciu, and an explicit formula for the homology group of the Milnor fiber boundary of generic arrangements.
https://park.itc.u-tokyo.ac.jp/MSF/topology/TuesdaySeminar/index_e.html
2025/10/06
Seminar on Geometric Complex Analysis
10:30-12:00 Room #128 (Graduate School of Math. Sci. Bldg.)
Yuya Takeuchi (Univ. of Tsukuba)
CR Paneitz operator on non-embeddable CR manifolds (Japanese)
https://forms.gle/gTP8qNZwPyQyxjTj8
Yuya Takeuchi (Univ. of Tsukuba)
CR Paneitz operator on non-embeddable CR manifolds (Japanese)
[ Abstract ]
The CR Paneitz operator, a CR invariant fourth-order linear differential operator, plays a crucial role in three-dimensional CR geometry. It is closely related to global embeddability, the CR positive mass theorem, and the logarithmic singularity of the Szegő kernel. In this talk, I will discuss the spectrum of the CR Paneitz operator on non-embeddable CR manifolds, with particular emphasis on how it differs from the embeddable case.
[ Reference URL ]The CR Paneitz operator, a CR invariant fourth-order linear differential operator, plays a crucial role in three-dimensional CR geometry. It is closely related to global embeddability, the CR positive mass theorem, and the logarithmic singularity of the Szegő kernel. In this talk, I will discuss the spectrum of the CR Paneitz operator on non-embeddable CR manifolds, with particular emphasis on how it differs from the embeddable case.
https://forms.gle/gTP8qNZwPyQyxjTj8
Tokyo Probability Seminar
16:30-18:00 Room #126 (Graduate School of Math. Sci. Bldg.)
The lecture is starting late. No Tea Time today.
Hiroshi Kawabi (Keio University)
Riemann多様体上の排他過程に対する流体力学極限
The lecture is starting late. No Tea Time today.
Hiroshi Kawabi (Keio University)
Riemann多様体上の排他過程に対する流体力学極限
[ Abstract ]
(コンパクトとは限らない)完備なRiemann多様体をグラフで離散化し, その上の排他過程に対するスケール極限を考察する。
本講演では, 石渡 聡 氏 (山形大学), 角田 謙吉 氏 (九州大学)と現在進行中の共同研究に基づき, 流体力学極限について得られた成果を報告する。
(コンパクトとは限らない)完備なRiemann多様体をグラフで離散化し, その上の排他過程に対するスケール極限を考察する。
本講演では, 石渡 聡 氏 (山形大学), 角田 謙吉 氏 (九州大学)と現在進行中の共同研究に基づき, 流体力学極限について得られた成果を報告する。
2025/10/03
Seminar on Probability and Statistics
16:00-17:10 Room #123 (Graduate School of Math. Sci. Bldg.)
Freddy Delbaen (ETH Zurich)
Writing Uncorrelated Random Variables as a sum of Independent Random Variables (English)
https://u-tokyo-ac-jp.zoom.us/meeting/register/-kK0DZB6SbeMyAye6ujPeA
Freddy Delbaen (ETH Zurich)
Writing Uncorrelated Random Variables as a sum of Independent Random Variables (English)
[ Abstract ]
With Majumdar I proved that for a random variable $X$ that is uncorrelated to a sigma algebra, there exists a best approximation by a random variable that is independent of the sigma algebra. Inductively we get a series of random variables whose terms are independent of the sigma algebra. We show that this series converge to $X$ in $L^2$. The proof uses the Knott-Smith theorem from transport theory. In an earlier version we could show that convergence took place in $L^1$.
[ Reference URL ]With Majumdar I proved that for a random variable $X$ that is uncorrelated to a sigma algebra, there exists a best approximation by a random variable that is independent of the sigma algebra. Inductively we get a series of random variables whose terms are independent of the sigma algebra. We show that this series converge to $X$ in $L^2$. The proof uses the Knott-Smith theorem from transport theory. In an earlier version we could show that convergence took place in $L^1$.
https://u-tokyo-ac-jp.zoom.us/meeting/register/-kK0DZB6SbeMyAye6ujPeA
2025/09/25
Applied Analysis
16:00-17:30 Room #128 (Graduate School of Math. Sci. Bldg.)
Fumihiko Onoue (Technische Universität München)
On the shape of fractional minimal surfaces (Japanese)
Fumihiko Onoue (Technische Universität München)
On the shape of fractional minimal surfaces (Japanese)
[ Abstract ]
Fractional perimeter (or fractional area) has been studied for more than a decade since Caffarelli, Roquejofffre, and Savin introduced its notion in 2010; however, there are still a lot of things unknown. In this talk, we discuss the shape of the boundary of sets minimizing their fractional perimeter under several boundary conditions, reviewing several interesting examples distinct from sets minimizing their classical perimeter. Moreover, if time permits, we present another notion of fractional area for smooth hypersurfaces with boundary, which was introduced by Paroni, Podio-Guidugli, and Seguin in 2018. Then we discuss the shape of critical points of their fractional area in several simple situations. This talk is partially based on a joint work with S. Dipierro and E. Valdinoci.
Fractional perimeter (or fractional area) has been studied for more than a decade since Caffarelli, Roquejofffre, and Savin introduced its notion in 2010; however, there are still a lot of things unknown. In this talk, we discuss the shape of the boundary of sets minimizing their fractional perimeter under several boundary conditions, reviewing several interesting examples distinct from sets minimizing their classical perimeter. Moreover, if time permits, we present another notion of fractional area for smooth hypersurfaces with boundary, which was introduced by Paroni, Podio-Guidugli, and Seguin in 2018. Then we discuss the shape of critical points of their fractional area in several simple situations. This talk is partially based on a joint work with S. Dipierro and E. Valdinoci.
2025/09/09
Operator Algebra Seminars
16:45-18:15 Room #126 (Graduate School of Math. Sci. Bldg.)
Kang Li (FAU Erlangen-Nürnberg)
Dimension theories from groupoids to classifiable $C^*$-algebras, and back again
[ Reference URL ]
https://www.ms.u-tokyo.ac.jp/seminar/operalge/future.html
Kang Li (FAU Erlangen-Nürnberg)
Dimension theories from groupoids to classifiable $C^*$-algebras, and back again
[ Reference URL ]
https://www.ms.u-tokyo.ac.jp/seminar/operalge/future.html
2025/08/22
thesis presentations
16:00-17:15 Room #128 (Graduate School of Math. Sci. Bldg.)
HOSHINO Mao (東京大学大学院数理科学研究科)
A tensor categorical aspect of quantum group actions
(量子群作用のテンソル圏的様相)
HOSHINO Mao (東京大学大学院数理科学研究科)
A tensor categorical aspect of quantum group actions
(量子群作用のテンソル圏的様相)
2025/08/19
Algebraic Geometry Seminar
13:30-15:00 Room #117 (Graduate School of Math. Sci. Bldg.)
Trung Tuyen Truong (University of Oslo)
Some new results concerning Tate's questions and generalisations
Trung Tuyen Truong (University of Oslo)
Some new results concerning Tate's questions and generalisations
[ Abstract ]
In the 1960s, Tate formulated (inspired by Weil's conjectures and a result of Serre on compact Kahler manifolds) a couple of questions concerning eigenvalues for pullback on cohomology of polarized endomorphisms. Grothendieck and Bombieri proposed Standard conjectures to solve these questions by Tate. The speaker, inspired by complex dynamics, proposed a generalisation of one of Tate's questions to rational maps and dynamical correspondences. This talk presents some new results and approaches (which are less demanding than the Standard conjectures, in that Standard Conjecture of Hodge type is not required) concerning these Tate's questions and generalisation. The talk includes joint works with Fei Hu and Junyi Xie.
In the 1960s, Tate formulated (inspired by Weil's conjectures and a result of Serre on compact Kahler manifolds) a couple of questions concerning eigenvalues for pullback on cohomology of polarized endomorphisms. Grothendieck and Bombieri proposed Standard conjectures to solve these questions by Tate. The speaker, inspired by complex dynamics, proposed a generalisation of one of Tate's questions to rational maps and dynamical correspondences. This talk presents some new results and approaches (which are less demanding than the Standard conjectures, in that Standard Conjecture of Hodge type is not required) concerning these Tate's questions and generalisation. The talk includes joint works with Fei Hu and Junyi Xie.
Tokyo-Nagoya Algebra Seminar
15:00-16:30 Online
Naoya Hiramae (Kyoto University)
自己入射的代数のCartan行列の正定値性と$\tau$-傾有限性 (Japanese)
[ Reference URL ]
https://www.math.nagoya-u.ac.jp/~aaron.chan/TNAseminar.html
Naoya Hiramae (Kyoto University)
自己入射的代数のCartan行列の正定値性と$\tau$-傾有限性 (Japanese)
[ Reference URL ]
https://www.math.nagoya-u.ac.jp/~aaron.chan/TNAseminar.html
Geometric Analysis Seminar
16:00-17:00 Room #123 (Graduate School of Math. Sci. Bldg.)
Hiro Lee Tanaka (Texas State University)
For Liouville sectors, Floer theory in families without Floer theory in families
https://sites.google.com/g.ecc.u-tokyo.ac.jp/geometricanalysisseminar/
Hiro Lee Tanaka (Texas State University)
For Liouville sectors, Floer theory in families without Floer theory in families
[ Abstract ]
Numbers do not have automorphisms, but most other mathematical objects do.
So when Floer theory yields non-numerical invariants, one can hope for symmetries to act on such invariants. Typically, one realizes these actions by carefully setting up an analytical framework for Floer theory to vary over the fibers of some bundle. In the setting of Floer theory for a class of symplectic manifolds called Liouville sectors, we show that a completely different technique -- localization of infinity-categories -- achieves the same goals, and more! This talk is based on some old joint work with Oleg Lazarev and Zachary Sylvan.
[ Reference URL ]Numbers do not have automorphisms, but most other mathematical objects do.
So when Floer theory yields non-numerical invariants, one can hope for symmetries to act on such invariants. Typically, one realizes these actions by carefully setting up an analytical framework for Floer theory to vary over the fibers of some bundle. In the setting of Floer theory for a class of symplectic manifolds called Liouville sectors, we show that a completely different technique -- localization of infinity-categories -- achieves the same goals, and more! This talk is based on some old joint work with Oleg Lazarev and Zachary Sylvan.
https://sites.google.com/g.ecc.u-tokyo.ac.jp/geometricanalysisseminar/
2025/07/31
Tokyo Probability Seminar
16:00-17:30 Room #128 (Graduate School of Math. Sci. Bldg.)
The lecture is on Thursday. The classroom is 128. We are having teatime from 15:15 in the common room on the second floor. Please join us.
Xinyi Li (Peking University)
Analyticity of 3D Brownian intersection exponents
The lecture is on Thursday. The classroom is 128. We are having teatime from 15:15 in the common room on the second floor. Please join us.
Xinyi Li (Peking University)
Analyticity of 3D Brownian intersection exponents
[ Abstract ]
In this talk, we will discuss the boundary Harnack principle (BHP) of the domain in \mathbb{R}^3 with the trace of a 3D Brownian motion removed and how it implies the analyticity of the intersection exponents for 3D Brownian motion. Based on a joint work (available at arXiv:2411.14921) with Yifan Gao (CityU HK), Yifan Li, Runsheng Liu and Xiangyi Liu (PKU).
In this talk, we will discuss the boundary Harnack principle (BHP) of the domain in \mathbb{R}^3 with the trace of a 3D Brownian motion removed and how it implies the analyticity of the intersection exponents for 3D Brownian motion. Based on a joint work (available at arXiv:2411.14921) with Yifan Gao (CityU HK), Yifan Li, Runsheng Liu and Xiangyi Liu (PKU).
2025/07/30
Number Theory Seminar
17:00-18:00 Room #117 (Graduate School of Math. Sci. Bldg.)
Bruno Chiarellotto (Dipartimento di Matematica "Tullio Levi-Civita", Universita' degli Studi di Padova)
The tempered tube and the tempered cohomology
https://www.math.unipd.it/~chiarbru/
Bruno Chiarellotto (Dipartimento di Matematica "Tullio Levi-Civita", Universita' degli Studi di Padova)
The tempered tube and the tempered cohomology
[ Abstract ]
We will discuss a recent joint work with F. Bambozzi and P. Vanni (https://arxiv.org/abs/2410.09473). In the derived analytic spaces in the non arch. setting there are opens where the sections not only converge but they have also some arithmetic properties (log-growth). We will discuss how to construct such a spaces and we will give some applications: to the classical log-growth transfer theorem and on a new interpretation of convergent cohomology where one can replace the classical tube of the rigid cohomology with a "tempered one".
[ Reference URL ]We will discuss a recent joint work with F. Bambozzi and P. Vanni (https://arxiv.org/abs/2410.09473). In the derived analytic spaces in the non arch. setting there are opens where the sections not only converge but they have also some arithmetic properties (log-growth). We will discuss how to construct such a spaces and we will give some applications: to the classical log-growth transfer theorem and on a new interpretation of convergent cohomology where one can replace the classical tube of the rigid cohomology with a "tempered one".
https://www.math.unipd.it/~chiarbru/
2025/07/29
Numerical Analysis Seminar
16:30-18:00 Room #123 (Graduate School of Math. Sci. Bldg.)
Takashi Suzuki (Osaka University)
An analytic proof of the Hodge decomposition on bounded domains in Euclidean space and its applications (Japanese)
Takashi Suzuki (Osaka University)
An analytic proof of the Hodge decomposition on bounded domains in Euclidean space and its applications (Japanese)
2025/07/28
Tokyo Probability Seminar
16:00-17:30 Room #126 (Graduate School of Math. Sci. Bldg.)
We are having teatime from 15:15 in the common room on the second floor. Please join us.
Syota Esaki (Oita University)
Difference between n-dimensional Cauchy distribution and n-times product of Cauchy distribution from perspective of measure concentration
We are having teatime from 15:15 in the common room on the second floor. Please join us.
Syota Esaki (Oita University)
Difference between n-dimensional Cauchy distribution and n-times product of Cauchy distribution from perspective of measure concentration
[ Abstract ]
確率解析と測度距離幾何学はそれぞれにおいて広く研究されているが，お互いの関わりはまだ深いとは言えない．ところが，両者ともに，極限定理，特に測度集中現象を通して深く関わりあうと考えることができる．本講演では確率論的な模型である多次元コーシー分布, または, 1次元コーシー分布の直積に基づく測度集中現象について述べ、それらの測度距離幾何的な相違点について述べる. 時間が許した場合には, これらに対応する安定分布の結果についても紹介する. この講演は東京都立大学の数川大輔氏と福岡大学の三石史人氏との共同研究に基づく．
確率解析と測度距離幾何学はそれぞれにおいて広く研究されているが，お互いの関わりはまだ深いとは言えない．ところが，両者ともに，極限定理，特に測度集中現象を通して深く関わりあうと考えることができる．本講演では確率論的な模型である多次元コーシー分布, または, 1次元コーシー分布の直積に基づく測度集中現象について述べ、それらの測度距離幾何的な相違点について述べる. 時間が許した場合には, これらに対応する安定分布の結果についても紹介する. この講演は東京都立大学の数川大輔氏と福岡大学の三石史人氏との共同研究に基づく．
2025/07/25
Colloquium
15:30-16:30 Room #大講義室(auditorium) (Graduate School of Math. Sci. Bldg.)
Izumi Okada (Graduate School of Mathematical Sciences, The University of Tokyo)
Recent Advances in Simple Random Walks (日本語)
Izumi Okada (Graduate School of Mathematical Sciences, The University of Tokyo)
Recent Advances in Simple Random Walks (日本語)
[ Abstract ]
A simple random walk is a stochastic process in which, for example in two dimensions, the walker moves at each time step to one of the four neighboring sites—up, down, left, or right—with equal probability 1/4. Although this model has been extensively studied for many years, a number of fundamental questions remain unsolved even in such a simple setting.In this talk, I will provide an overview of recent developments in the field, along with some of our recent results.
A simple random walk is a stochastic process in which, for example in two dimensions, the walker moves at each time step to one of the four neighboring sites—up, down, left, or right—with equal probability 1/4. Although this model has been extensively studied for many years, a number of fundamental questions remain unsolved even in such a simple setting.In this talk, I will provide an overview of recent developments in the field, along with some of our recent results.
Algebraic Geometry Seminar
13:30-15:00 Room #118 (Graduate School of Math. Sci. Bldg.)
Akihiro Kanemitsu (Tokyo Metropolitan University)
Quintic del Pezzo threefolds in positive and mixed characteristic
Akihiro Kanemitsu (Tokyo Metropolitan University)
Quintic del Pezzo threefolds in positive and mixed characteristic
[ Abstract ]
We will show that, over any base scheme, (families of) quintic del Pezzo threefolds V5 are classified by non-degenerate ternary symmetric bilinear forms.
As applications, we will discuss (1) the geometry of quintic del Pezzo threefolds in positive characteristic, especially in characteristic two, and (2) finiteness results of V5 over number fields/rings of integers.
(Based on joint work with Tetsushi Ito, Teppei Takamatsu, Yuuji Tanaka)
We will show that, over any base scheme, (families of) quintic del Pezzo threefolds V5 are classified by non-degenerate ternary symmetric bilinear forms.
As applications, we will discuss (1) the geometry of quintic del Pezzo threefolds in positive characteristic, especially in characteristic two, and (2) finiteness results of V5 over number fields/rings of integers.
(Based on joint work with Tetsushi Ito, Teppei Takamatsu, Yuuji Tanaka)
2025/07/22
Operator Algebra Seminars
16:45-18:15 Room #117 (Graduate School of Math. Sci. Bldg.)
Giovanni Ferrer (Ohio State University)
Higher quantum symmetries
[ Reference URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm
Giovanni Ferrer (Ohio State University)
Higher quantum symmetries
[ Reference URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm
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