本文印刷
全画面プリント
今後の予定
過去の記録 ～04/25｜本日 04/26 | 今後の予定 04/27～
2026年04月27日(月)
複素解析幾何セミナー
10:30-12:00 数理科学研究科棟(駒場) 126号室
大野 高志 氏 (京大数理研)
Manton’s Exotic Vortex Equations (Japanese)
https://forms.gle/8ERsVDLuKHwbVzm57
大野 高志 氏 (京大数理研)
Manton’s Exotic Vortex Equations (Japanese)
[ 講演概要 ]
The vortex equation is a second-order PDE on a Riemann surface, defined in terms of a triple consisting of a holomorphic line bundle, a section, and a Hermitian metric. Its solutions are closely related to Hermitian–Einstein metrics and to geometric structures such as metrics with conical singularities. In https://arxiv.org/abs/1612.06710, Manton introduced several generalizations of the vortex equation, leading to five distinct types of vortex equations, which we refer to as Manton’s exotic vortex equations. In this talk, I will introduce these equations and discuss the existence of their solutions. I will also explain how these solutions can be obtained via dimensional reduction of a solution of Hermitian–Einstein equation.
[ 参考URL ]The vortex equation is a second-order PDE on a Riemann surface, defined in terms of a triple consisting of a holomorphic line bundle, a section, and a Hermitian metric. Its solutions are closely related to Hermitian–Einstein metrics and to geometric structures such as metrics with conical singularities. In https://arxiv.org/abs/1612.06710, Manton introduced several generalizations of the vortex equation, leading to five distinct types of vortex equations, which we refer to as Manton’s exotic vortex equations. In this talk, I will introduce these equations and discuss the existence of their solutions. I will also explain how these solutions can be obtained via dimensional reduction of a solution of Hermitian–Einstein equation.
https://forms.gle/8ERsVDLuKHwbVzm57
東京確率論セミナー
14:00-17:30 数理科学研究科棟(駒場) 126号室
講演の開始が早くなっています。15:30~ 教室126でTea timeを行います。ぜひこちらにもご参加ください。
Clément Cosco 氏 (Université Paris Dauphine) 14:00-15:30
The maximum of 2d directed polymers. (Joint work with Shuta Nakajima and Ofer Zeitouni.)
TBA
講演の開始が早くなっています。15:30~ 教室126でTea timeを行います。ぜひこちらにもご参加ください。
Clément Cosco 氏 (Université Paris Dauphine) 14:00-15:30
The maximum of 2d directed polymers. (Joint work with Shuta Nakajima and Ofer Zeitouni.)
[ 講演概要 ]
Directed polymers can be described as a tilting of the simple random walk, where some local random noise can attract or repel the trajectory of the walk. In the subcritical regime of the two-dimensional model, the partition function is known to be asymptotically approximated by a Gaussian log-correlated field. In a work in collaboration with Shuta Nakajima and Ofer Zeitouni, we could refine this result by proving that the maximum of the partition function field converges to that of a branching Brownian motion, which is the source of the log-correlation. In this talk, I will introduce the model as well as the objects related to it and present our result.
Subhro Ghosh 氏 (National University of Singapore) 16:00-17:30Directed polymers can be described as a tilting of the simple random walk, where some local random noise can attract or repel the trajectory of the walk. In the subcritical regime of the two-dimensional model, the partition function is known to be asymptotically approximated by a Gaussian log-correlated field. In a work in collaboration with Shuta Nakajima and Ofer Zeitouni, we could refine this result by proving that the maximum of the partition function field converges to that of a branching Brownian motion, which is the source of the log-correlation. In this talk, I will introduce the model as well as the objects related to it and present our result.
TBA
[ 講演概要 ]
TBA
TBA
2026年04月28日(火)
トポロジー火曜セミナー
16:00-17:30 数理科学研究科棟(駒場) hybrid/056号室
対面参加、オンライン参加のいずれの場合もセミナーのホームページから参加登録を行って下さい。
佐野 岳人 氏 (理化学研究所)
A y-ification of Khovanov homology (JAPANESE)
https://park.itc.u-tokyo.ac.jp/MSF/topology/TuesdaySeminar/index_e.html
対面参加、オンライン参加のいずれの場合もセミナーのホームページから参加登録を行って下さい。
佐野 岳人 氏 (理化学研究所)
A y-ification of Khovanov homology (JAPANESE)
[ 講演概要 ]
In this talk, I will explain the main results of my recent paper (arXiv:2602.17435).
Khovanov homology is a categorification of the Jones polynomial, introduced by M. Khovanov. A persistent theme in the subject is that adding extra structures on Khovanov homology strengthens the invariant, and often detects phenomena invisible at the level of polynomials or bigraded vector spaces.
Motivated by the y-ification of HOMFLY--PT homology by Gorsky and Hogancamp, and the sl2-action constructed by Gorsky, Hogancamp and Mellit, we construct a y-ification of Khovanov homology and define an action of the element e in sl2 on these y-ifications. Our construction is compatible with the previous ones via Rasmussen's spectral sequence from HOMFLY--PT homology to Khovanov homology; yet our approach is more elementary and suited to diagrammatic and algorithmic computations. As an application, we show that the additional structure can distinguish knots with identical Khovanov homology and identical HOMFLY--PT homology, in particular the Conway knot and the Kinoshita--Terasaka knot.
[ 参考URL ]In this talk, I will explain the main results of my recent paper (arXiv:2602.17435).
Khovanov homology is a categorification of the Jones polynomial, introduced by M. Khovanov. A persistent theme in the subject is that adding extra structures on Khovanov homology strengthens the invariant, and often detects phenomena invisible at the level of polynomials or bigraded vector spaces.
Motivated by the y-ification of HOMFLY--PT homology by Gorsky and Hogancamp, and the sl2-action constructed by Gorsky, Hogancamp and Mellit, we construct a y-ification of Khovanov homology and define an action of the element e in sl2 on these y-ifications. Our construction is compatible with the previous ones via Rasmussen's spectral sequence from HOMFLY--PT homology to Khovanov homology; yet our approach is more elementary and suited to diagrammatic and algorithmic computations. As an application, we show that the additional structure can distinguish knots with identical Khovanov homology and identical HOMFLY--PT homology, in particular the Conway knot and the Kinoshita--Terasaka knot.
https://park.itc.u-tokyo.ac.jp/MSF/topology/TuesdaySeminar/index_e.html
作用素環セミナー
16:45-18:15 数理科学研究科棟(駒場) 126号室
Roozbeh Hazrat 氏 (Western Sydney University)
An attempt to classify combinatorial algebras
[ 参考URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm
Roozbeh Hazrat 氏 (Western Sydney University)
An attempt to classify combinatorial algebras
[ 参考URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm
Lie群論・表現論セミナー
16:00-17:00 数理科学研究科棟(駒場) 128号室
Khalid Koufany 氏 (University of Lorraine)
Geometric Means that preserve sparsity on homogeneous cones
(English)
Khalid Koufany 氏 (University of Lorraine)
Geometric Means that preserve sparsity on homogeneous cones
(English)
[ 講演概要 ]
This talk starts from a simple question: how can one define a geometric mean for sparse positive definite matrices without destroying their zero pattern?
For the arrowhead pattern, this leads naturally to the five-dimensional Vinberg cone, a basic non-symmetric homogeneous cone.
I will present two intrinsic means on this cone: a Cholesky-Vinberg mean built from triangular Cholesky factors, and a logarithmic Vinberg mean built from global clan (Vinberg algebra) coordinates.
The first is tied to a flat affine geometry with torsion, while the second belongs to a torsion-free flat geometry.
I will also explain why these means differ from the classical Riemannian midpoint and why this difference is a genuinely non-symmetric phenomenon.
If time permits, I will give an application to quantum information theory.
This talk starts from a simple question: how can one define a geometric mean for sparse positive definite matrices without destroying their zero pattern?
For the arrowhead pattern, this leads naturally to the five-dimensional Vinberg cone, a basic non-symmetric homogeneous cone.
I will present two intrinsic means on this cone: a Cholesky-Vinberg mean built from triangular Cholesky factors, and a logarithmic Vinberg mean built from global clan (Vinberg algebra) coordinates.
The first is tied to a flat affine geometry with torsion, while the second belongs to a torsion-free flat geometry.
I will also explain why these means differ from the classical Riemannian midpoint and why this difference is a genuinely non-symmetric phenomenon.
If time permits, I will give an application to quantum information theory.
日仏数学拠点FJ-LMIセミナー
16:00-17:00 数理科学研究科棟(駒場) 128号室
Khalid Koufany 氏 (Université de Lorraine)
Geometric Means that preserve sparsity on homogeneous cones
(英語)
https://fj-lmi.cnrs.fr/seminars/
Khalid Koufany 氏 (Université de Lorraine)
Geometric Means that preserve sparsity on homogeneous cones
(英語)
[ 講演概要 ]
This talk starts from a simple question: how can one define a geometric mean for sparse positive definite matrices without destroying their zero pattern?
For the arrowhead pattern, this leads naturally to the five-dimensional Vinberg cone, a basic non-symmetric homogeneous cone.
I will present two intrinsic means on this cone: a Cholesky-Vinberg mean built from triangular Cholesky factors, and a logarithmic Vinberg mean built from global clan (Vinberg algebra) coordinates.
The first is tied to a flat affine geometry with torsion, while the second belongs to a torsion-free flat geometry.
I will also explain why these means differ from the classical Riemannian midpoint and why this difference is a genuinely non-symmetric phenomenon.
If time permits, I will give an application to quantum information theory.
[ 参考URL ]This talk starts from a simple question: how can one define a geometric mean for sparse positive definite matrices without destroying their zero pattern?
For the arrowhead pattern, this leads naturally to the five-dimensional Vinberg cone, a basic non-symmetric homogeneous cone.
I will present two intrinsic means on this cone: a Cholesky-Vinberg mean built from triangular Cholesky factors, and a logarithmic Vinberg mean built from global clan (Vinberg algebra) coordinates.
The first is tied to a flat affine geometry with torsion, while the second belongs to a torsion-free flat geometry.
I will also explain why these means differ from the classical Riemannian midpoint and why this difference is a genuinely non-symmetric phenomenon.
If time permits, I will give an application to quantum information theory.
https://fj-lmi.cnrs.fr/seminars/
2026年05月07日(木)
応用解析セミナー
16:00-17:30 数理科学研究科棟(駒場) 002号室
熊谷 健太 氏 (東京大学)
Large-time behavior and grow-up rates of inhomogeneous semilinear heat equations, via the bifurcation structure of the stationary problem (Japanese)
熊谷 健太 氏 (東京大学)
Large-time behavior and grow-up rates of inhomogeneous semilinear heat equations, via the bifurcation structure of the stationary problem (Japanese)
[ 講演概要 ]
球領域上における指数型非線形項と非斉次項を伴う半線型熱方程式, およびその定常問題を考察する. 非斉次項を伴わない場合，定常問題の分岐構造は空間10次元を境に変化することが知られている. これに起因して熱方程式の解の漸近挙動も変化し，特に10次元以上では無限時間爆発（grow-up）が生じる.
本講演では，空間次元が10以上の場合に限り，非斉次項がある閾値を超えると，定常問題の分岐構造が従来とは異なる型へと変化することを示す. さらに，この変化に対応して，熱方程式における解の無限時間爆発現象が消失することを明らかにする. また，解の爆発レートを明示的に導出することにより，この消失現象に対する定量的理解を与える. 特に，吸収項が閾値に一致する臨界的状況では，爆発レートは対数型へと変化し，11次元においてはさらに log–log 型の第二項が現れる.
これら一連の現象の変化は，いずれも定常問題における特異解によって支配されている.
本研究は東北大学の岡優丞氏との共同研究に基づく.
球領域上における指数型非線形項と非斉次項を伴う半線型熱方程式, およびその定常問題を考察する. 非斉次項を伴わない場合，定常問題の分岐構造は空間10次元を境に変化することが知られている. これに起因して熱方程式の解の漸近挙動も変化し，特に10次元以上では無限時間爆発（grow-up）が生じる.
本講演では，空間次元が10以上の場合に限り，非斉次項がある閾値を超えると，定常問題の分岐構造が従来とは異なる型へと変化することを示す. さらに，この変化に対応して，熱方程式における解の無限時間爆発現象が消失することを明らかにする. また，解の爆発レートを明示的に導出することにより，この消失現象に対する定量的理解を与える. 特に，吸収項が閾値に一致する臨界的状況では，爆発レートは対数型へと変化し，11次元においてはさらに log–log 型の第二項が現れる.
これら一連の現象の変化は，いずれも定常問題における特異解によって支配されている.
本研究は東北大学の岡優丞氏との共同研究に基づく.
2026年05月11日(月)
複素解析幾何セミナー
10:30-12:00 数理科学研究科棟(駒場) 126号室
Luc Pirio 氏 (CNRS)
(English)
[ 参考URL ]
https://forms.gle/8ERsVDLuKHwbVzm57
Luc Pirio 氏 (CNRS)
(English)
[ 参考URL ]
https://forms.gle/8ERsVDLuKHwbVzm57
2026年05月12日(火)
トポロジー火曜セミナー
16:00-17:00 オンライン開催
セミナーのホームページから参加登録を行って下さい。
Sanghoon Kwak 氏 (Seoul National University)
Mapping class group of Infinite graph: 'Big' Out(Fn) (ENGLISH)
https://park.itc.u-tokyo.ac.jp/MSF/topology/TuesdaySeminar/index_e.html
セミナーのホームページから参加登録を行って下さい。
Sanghoon Kwak 氏 (Seoul National University)
Mapping class group of Infinite graph: 'Big' Out(Fn) (ENGLISH)
[ 講演概要 ]
Algom-Kfir and Bestvina introduced the mapping class groups of locally finite, infinite graphs in 2021. Since Out(Fn) can be realized as the mapping group of a finite graph, their construction may be viewed as a "big" version of Out(Fn). In this talk, we survey the algebraic and coarse geometric properties of these groups and discuss a relationship with mapping class groups of infinite-type surfaces ("big mapping class groups"). This talk is based on joint work with Ryan Dickmann, George Domat, and Hannah Hoganson, in various collaborations.
[ 参考URL ]Algom-Kfir and Bestvina introduced the mapping class groups of locally finite, infinite graphs in 2021. Since Out(Fn) can be realized as the mapping group of a finite graph, their construction may be viewed as a "big" version of Out(Fn). In this talk, we survey the algebraic and coarse geometric properties of these groups and discuss a relationship with mapping class groups of infinite-type surfaces ("big mapping class groups"). This talk is based on joint work with Ryan Dickmann, George Domat, and Hannah Hoganson, in various collaborations.
https://park.itc.u-tokyo.ac.jp/MSF/topology/TuesdaySeminar/index_e.html
作用素環セミナー
16:45-18:15 数理科学研究科棟(駒場) 126号室
Camila Sehnem 氏 (京大数理研)
Injective envelopes for partial $C^*$-dynamical systems
[ 参考URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm
Camila Sehnem 氏 (京大数理研)
Injective envelopes for partial $C^*$-dynamical systems
[ 参考URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm
代数幾何学セミナー
13:30-15:00 数理科学研究科棟(駒場) 128号室
斎藤 秀司 氏 (東京大学)
TBA
斎藤 秀司 氏 (東京大学)
TBA
[ 講演概要 ]
TBA
TBA
2026年05月14日(木)
幾何解析セミナー
14:30-16:45 数理科学研究科棟(駒場) 117号室
Jacob Bernstein 氏 (Johns Hopkins University) 14:30-15:30
Complexity of submanifolds and Colding-Minicozzi entropy (英語)
https://sites.google.com/g.ecc.u-tokyo.ac.jp/geometricanalysisseminar/
Peter Topping 氏 (University of Warwick) 15:45-16:45
TBA (英語)
https://sites.google.com/g.ecc.u-tokyo.ac.jp/geometricanalysisseminar/
Jacob Bernstein 氏 (Johns Hopkins University) 14:30-15:30
Complexity of submanifolds and Colding-Minicozzi entropy (英語)
[ 講演概要 ]
Colding-Minicozzi entropy is a natural quantity associated to mean curvature flow which measures complexity of submanifolds of Euclidean space. We discuss some (nearly) optimal relationships between entropy and areas of (minimal) submanifolds of the sphere.
[ 参考URL ]Colding-Minicozzi entropy is a natural quantity associated to mean curvature flow which measures complexity of submanifolds of Euclidean space. We discuss some (nearly) optimal relationships between entropy and areas of (minimal) submanifolds of the sphere.
https://sites.google.com/g.ecc.u-tokyo.ac.jp/geometricanalysisseminar/
Peter Topping 氏 (University of Warwick) 15:45-16:45
TBA (英語)
[ 講演概要 ]
TBA
[ 参考URL ]TBA
https://sites.google.com/g.ecc.u-tokyo.ac.jp/geometricanalysisseminar/
2026年05月19日(火)
作用素環セミナー
16:45-18:15 数理科学研究科棟(駒場) 126号室
上川弘郎 氏 (京都大学)
未定
[ 参考URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm
上川弘郎 氏 (京都大学)
未定
[ 参考URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm
PDE実解析研究会
10:30-11:30 数理科学研究科棟(駒場) 128号室
通常の会場と異なります。
浜向 直 氏 (北海道大学 大学院理学研究院)
対数凹関数に対するGagliardo-Nirenberg型不等式と非線形楕円型固有値問題への応用 (日本語)
通常の会場と異なります。
浜向 直 氏 (北海道大学 大学院理学研究院)
対数凹関数に対するGagliardo-Nirenberg型不等式と非線形楕円型固有値問題への応用 (日本語)
[ 講演概要 ]
Gagliardo-Nirenberg型不等式を、遠方で減衰する対数凹関数に対して導きます。証明では、関数から定まるエントロピーに対する上下からの評価が鍵となります。上からの評価には対数型ソボレフの不等式、下からの評価には関数の対数凹性を利用します。また、得られたGagliardo-Nirenberg型不等式における定数の精度についても議論します。さらに、完全非線形楕円型固有値問題の解に適用して、固有値に対する下からの評価を導きます。本講演の内容は、藤田安啓氏、五十嵐蓮氏との共同研究に基づきます。
Gagliardo-Nirenberg型不等式を、遠方で減衰する対数凹関数に対して導きます。証明では、関数から定まるエントロピーに対する上下からの評価が鍵となります。上からの評価には対数型ソボレフの不等式、下からの評価には関数の対数凹性を利用します。また、得られたGagliardo-Nirenberg型不等式における定数の精度についても議論します。さらに、完全非線形楕円型固有値問題の解に適用して、固有値に対する下からの評価を導きます。本講演の内容は、藤田安啓氏、五十嵐蓮氏との共同研究に基づきます。
2026年05月22日(金)
代数幾何学セミナー
13:15-14:45 数理科学研究科棟(駒場) 117号室
Justin Sawon 氏 (University of North Carolina Chapel Hill)
Classification results for Lagrangian fibrations
Justin Sawon 氏 (University of North Carolina Chapel Hill)
Classification results for Lagrangian fibrations
[ 講演概要 ]
A Lagrangian fibration on a holomorphic symplectic manifold or variety is one whose general fibre is an abelian variety that is Lagrangian with respect to the symplectic form. Examples were constructed by Beauville/Mukai whose fibres are Jacobians of curves, and by Markushevich-Tikhomirov, Arbarella-Sacca-Ferretti, Matteini, S-Shen, and Brakkee-Camere-Grossi-Pertusi-Sacca-Viktorova whose fibres are Prym varieties of curves with involutions. In all of these examples the family of curves is a linear system on a K3 surface, suggesting the question: is this always the case? Markushevich answered this affirmatively in the genus two case: if the relative compactified Jacobian of a family of genus two curves is a Lagrangian fibration then the curves all lie on a K3 surface, and the Lagrangian fibration is a Beauville-Mukai system. In this talk I will describe our generalization of this result to higher genus, and also to relative Prym varieties of genus three covers with involutions (joint work with Xuqiang Qin).
A Lagrangian fibration on a holomorphic symplectic manifold or variety is one whose general fibre is an abelian variety that is Lagrangian with respect to the symplectic form. Examples were constructed by Beauville/Mukai whose fibres are Jacobians of curves, and by Markushevich-Tikhomirov, Arbarella-Sacca-Ferretti, Matteini, S-Shen, and Brakkee-Camere-Grossi-Pertusi-Sacca-Viktorova whose fibres are Prym varieties of curves with involutions. In all of these examples the family of curves is a linear system on a K3 surface, suggesting the question: is this always the case? Markushevich answered this affirmatively in the genus two case: if the relative compactified Jacobian of a family of genus two curves is a Lagrangian fibration then the curves all lie on a K3 surface, and the Lagrangian fibration is a Beauville-Mukai system. In this talk I will describe our generalization of this result to higher genus, and also to relative Prym varieties of genus three covers with involutions (joint work with Xuqiang Qin).
2026年05月25日(月)
複素解析幾何セミナー
10:30-12:00 数理科学研究科棟(駒場) 126号室
大橋 美佐 氏 (名古屋工業大学)
(Japanese)
[ 参考URL ]
https://forms.gle/8ERsVDLuKHwbVzm57
大橋 美佐 氏 (名古屋工業大学)
(Japanese)
[ 参考URL ]
https://forms.gle/8ERsVDLuKHwbVzm57
2026年05月26日(火)
作用素環セミナー
16:45-18:15 数理科学研究科棟(駒場) 126号室
西原拓生 氏 (京大数理研)
Compact group actions and $G$-kernels on von Neumann algebras
[ 参考URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar-e.htm
西原拓生 氏 (京大数理研)
Compact group actions and $G$-kernels on von Neumann algebras
[ 参考URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar-e.htm
数値解析セミナー
16:30-18:00 数理科学研究科棟(駒場) 002号室
Qin Sheng 氏 (Baylor University)
Advances in Splitting: Intercardinal Approaches to Nonlinear Hideo Kawarada Equations
(English)
https://sites.google.com/g.ecc.u-tokyo.ac.jp/utnas-bulletin-board/
Qin Sheng 氏 (Baylor University)
Advances in Splitting: Intercardinal Approaches to Nonlinear Hideo Kawarada Equations
(English)
[ 講演概要 ]
This presentation addresses two main issues. First, we shall discuss recent advancements in both exponential and non-exponential splitting methods, with particular emphasis on their stability, accuracy and global error estimates. Second, we shall introduce a new splitting configuration for solving nonlinear Hideo Kawarada equations with mixed derivative terms. This approach leads to intercardinal splitting finite-difference schemes that provide efficient and accurate numerical approximations of the underlying solutions.
We shall further demonstrate that the resulting implicit methods are numerically stable, convergent, and efficient, while preserving key physical properties such as the positivity and monotonicity. The dynamic orders of accuracy of the proposed algorithms will be illustrated using generalized Milne devices. Simulation examples of the solution procedure will be presented and investigated, and several open problems will also be outlined.
[ 参考URL ]This presentation addresses two main issues. First, we shall discuss recent advancements in both exponential and non-exponential splitting methods, with particular emphasis on their stability, accuracy and global error estimates. Second, we shall introduce a new splitting configuration for solving nonlinear Hideo Kawarada equations with mixed derivative terms. This approach leads to intercardinal splitting finite-difference schemes that provide efficient and accurate numerical approximations of the underlying solutions.
We shall further demonstrate that the resulting implicit methods are numerically stable, convergent, and efficient, while preserving key physical properties such as the positivity and monotonicity. The dynamic orders of accuracy of the proposed algorithms will be illustrated using generalized Milne devices. Simulation examples of the solution procedure will be presented and investigated, and several open problems will also be outlined.
https://sites.google.com/g.ecc.u-tokyo.ac.jp/utnas-bulletin-board/
2026年06月01日(月)
複素解析幾何セミナー
10:30-12:00 数理科学研究科棟(駒場) 126号室
小森 洋平 氏 (早稲田大学)
(Japanese)
[ 参考URL ]
https://forms.gle/8ERsVDLuKHwbVzm57
小森 洋平 氏 (早稲田大学)
(Japanese)
[ 参考URL ]
https://forms.gle/8ERsVDLuKHwbVzm57
2026年06月02日(火)
作用素環セミナー
16:45-18:15 数理科学研究科棟(駒場) 126号室
西中祐介 氏 (大阪公立大)
Costello-Gwilliam factorization algebras and vertex algebras
[ 参考URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm
西中祐介 氏 (大阪公立大)
Costello-Gwilliam factorization algebras and vertex algebras
[ 参考URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm
2026年06月04日(木)
応用解析セミナー
16:00-17:30 数理科学研究科棟(駒場) 002号室
白木 尚武 氏 (University of Zagreb)
Beckner's sharp inequalities revisited on binary cubes (Japanese)
白木 尚武 氏 (University of Zagreb)
Beckner's sharp inequalities revisited on binary cubes (Japanese)
[ 講演概要 ]
The Hausdorff–Young inequality and Young’s convolution inequality are fundamental tools in harmonic analysis. The landmark paper “Inequalities in Fourier Analysis” by William Beckner (Ann. of Math., 1975) established the exact values of the sharp constants appearing in these inequalities. Recently, these inequalities have received renewed attention in the setting of binary cubes, driven by applications in additive combinatorics through works by Kane–Tao, de Dios Pont–Greenfeld–Ivanisvili–Madrid, and others. In this discrete setting, the sharp constant is known to be 1 and is no longer the central issue. Instead, the focus shifts to the range of exponents for which the Hausdorff–Young inequality and Young’s convolution inequality hold — a range that is enlarged compared to the classical case. In this talk, we aim to fully characterize this range. This is joint work with Tonći Crmarić (University of Split) and Vjekoslav Kovač (University of Zagreb).
The Hausdorff–Young inequality and Young’s convolution inequality are fundamental tools in harmonic analysis. The landmark paper “Inequalities in Fourier Analysis” by William Beckner (Ann. of Math., 1975) established the exact values of the sharp constants appearing in these inequalities. Recently, these inequalities have received renewed attention in the setting of binary cubes, driven by applications in additive combinatorics through works by Kane–Tao, de Dios Pont–Greenfeld–Ivanisvili–Madrid, and others. In this discrete setting, the sharp constant is known to be 1 and is no longer the central issue. Instead, the focus shifts to the range of exponents for which the Hausdorff–Young inequality and Young’s convolution inequality hold — a range that is enlarged compared to the classical case. In this talk, we aim to fully characterize this range. This is joint work with Tonći Crmarić (University of Split) and Vjekoslav Kovač (University of Zagreb).
2026年06月05日(金)
代数幾何学セミナー
13:15-14:45 数理科学研究科棟(駒場) 117号室
Young-Hoon Kiem 氏 (Korea Institute for Advanced Study)
TBA
Young-Hoon Kiem 氏 (Korea Institute for Advanced Study)
TBA
[ 講演概要 ]
TBA
TBA
2026年06月09日(火)
作用素環セミナー
16:45-18:15 数理科学研究科棟(駒場) 126号室
星野泰佑 氏 (東大数理)
Rigidity for graph-wreath product II$_1$ factors
[ 参考URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm
星野泰佑 氏 (東大数理)
Rigidity for graph-wreath product II$_1$ factors
[ 参考URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm
2026年06月16日(火)
作用素環セミナー
16:45-18:15 数理科学研究科棟(駒場) 126号室
石倉宙樹 氏 (京大数理研)
Borel planar complexes and soficity
[ 参考URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm
石倉宙樹 氏 (京大数理研)
Borel planar complexes and soficity
[ 参考URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm
2026年07月07日(火)
作用素環セミナー
16:45-18:15 数理科学研究科棟(駒場) 126号室
橋本七海 氏 (慶応大)
Equivalence of categories of KK-theory or E-theory for $C^*$-algebras over topological spaces by reflection functors
[ 参考URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm
橋本七海 氏 (慶応大)
Equivalence of categories of KK-theory or E-theory for $C^*$-algebras over topological spaces by reflection functors
[ 参考URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm
