Seminar information archive

Seminar information archive ~11/09Today's seminar 11/10 | Future seminars 11/11~

2021/03/29

Seminar on Probability and Statistics

14:00-15:10   Online
Register at least 3 days before at the reference URL. The URL for participation sent before the seminar.
Masaaki Imaizumi (University of Tokyo)
On Gaussian Approximation for M-Estimator (JAPANESE)
[ Abstract ]
This study develops a non-asymptotic Gaussian approximation theory for distributions of M-estimators, which are defined as maximizers of empirical criterion functions. In existing mathematical statistics literature, numerous studies have focused on approximating the distributions of the M-estimators for statistical inference. In contrast to the existing approaches, which mainly focus on limiting behaviors, this study employs a non-asymptotic approach, establishes abstract Gaussian approximation results for maximizers of empirical criteria, and proposes a Gaussian multiplier bootstrap approximation method. Our developments can be considered as extensions of the seminal works on the approximation theory for distributions of suprema of empirical processes toward their maximizers. Through this work, we shed new lights on the statistical theory of M-estimators. Our theory covers not only regular estimators, such as the least absolute deviations, but also some non-regular cases where it is difficult to derive or to approximate numerically the limiting distributions such as non-Donsker classes and cube root estimators.
[ Reference URL ]
https://docs.google.com/forms/d/e/1FAIpQLSfjQhmmZjWUllB6pQeEMGDRcLCe_0JPgVbEA05rHtcDYAZzqg/viewform

2021/03/24

Seminar on Probability and Statistics

14:30-16:00   Online
Register at least 3 days before at the reference URL. The URL for participation sent before the seminar.
Rachel Fewster (University of Auckland)
Stochastic modelling in ecology: why is it interesting? (ENGLISH)
[ Abstract ]
Asia-Pacific Seminar in Probability and Statistics https://sites.google.com/view/apsps/home

The ecological sciences offer rich pickings for stochastic modellers. There is currently an abundance of new technologies for monitoring wildlife and biodiversity, for which no practicable data-analysis methods exist. Often, modelling approaches that are motivated by a specific problem with relatively narrow focus can turn out to have surprisingly broad application elsewhere. As the generality of the problem structure becomes clear, this can also motivate new statistical theory.

I will describe some ecological modelling scenarios that have led to interesting developments from methodological and theoretical perspectives. As time allows, these will include: saddlepoint approximations for dealing with data corrupted by non-invertible linear transformations; information theory for assuring that it is a good idea to unite data from multiple sources; and methods for dealing with so-called 'enigmatic' data from remote sensors, involving a blend of ideas from point processes, queuing theory, and trigonometry. All scenarios will be generously illustrated with pictures of charismatic wildlife.

This talk covers joint work with numerous collaborators, especially Joey Wei Zhang, Mark Bravington, Peter Jupp, Jesse Goodman, Martin Hazelton, Godrick Oketch, Ben Stevenson, David Borchers, Paul van Dam-Bates, and Stephen Marsland.
[ Reference URL ]
https://docs.google.com/forms/d/e/1FAIpQLSf05P9fCZ5Wkasc7clW1XBpkeONPSjPKuCkNYb3oIqnOAu5Mg/viewform

2021/03/19

Colloquium

15:00-17:30   Online
Yoshikazu Giga (University of Tokyo) 15:00-16:00
Effects of viscosity and diffusion described by differential equations (JAPANESE)
Toshitake Kohno (Meiji University/University of Tokyo) 16:30-17:30
Monodromy representations in higher categories and iterated integrals (JAPANESE)

Lectures

18:00-19:00   Online
Day 3 of a series of three lectures (3/17,18,19)
Matthew Morrow (CNRS, IMJ-PRG)
Progress in syntomic cohomology (ENGLISH)
[ Abstract ]
The talks will present a survey of the (quasi)syntomic cohomology theory introduced by Bhatt, Scholze, and the speaker; this provides a variant of the syntomic cohomology of Fontaine, Kato, and Messing which has the advantage of being defined in a greater degree of generality and working well with torsion coefficients even for small primes. Although it underlies in principle a general theory of p-adic étale motivic cohomology, the talks will probably focus more on arithmetic aspects such as applications in p-adic Hodge theory. Based on various projects joint with Antieau, Bhatt, Clausen, Kelly, Lüders, Mathew, Nikolaus, and Scholze.
[ Reference URL ]
https://www.ms.u-tokyo.ac.jp/~shiho/spparis/index.html

2021/03/18

Lectures

17:30-18:30   Online
Day 2 of a series of three lectures (3/17,18,19)
Matthew Morrow (CNRS, IMJ-PRG)
Progress in syntomic cohomology (ENGLISH)
[ Abstract ]
The talks will present a survey of the (quasi)syntomic cohomology theory introduced by Bhatt, Scholze, and the speaker; this provides a variant of the syntomic cohomology of Fontaine, Kato, and Messing which has the advantage of being defined in a greater degree of generality and working well with torsion coefficients even for small primes. Although it underlies in principle a general theory of p-adic étale motivic cohomology, the talks will probably focus more on arithmetic aspects such as applications in p-adic Hodge theory. Based on various projects joint with Antieau, Bhatt, Clausen, Kelly, Lüders, Mathew, Nikolaus, and Scholze.
[ Reference URL ]
https://www.ms.u-tokyo.ac.jp/~shiho/spparis/index.html

2021/03/17

Lectures

17:30-18:30   Online
Day 1 of a series of three lectures (3/17,18,19)
Matthew Morrow (CNRS, IMJ-PRG)
Progress in syntomic cohomology (ENGLISH)
[ Abstract ]
The talks will present a survey of the (quasi)syntomic cohomology theory introduced by Bhatt, Scholze, and the speaker; this provides a variant of the syntomic cohomology of Fontaine, Kato, and Messing which has the advantage of being defined in a greater degree of generality and working well with torsion coefficients even for small primes. Although it underlies in principle a general theory of p-adic étale motivic cohomology, the talks will probably focus more on arithmetic aspects such as applications in p-adic Hodge theory. Based on various projects joint with Antieau, Bhatt, Clausen, Kelly, Lüders, Mathew, Nikolaus, and Scholze.
[ Reference URL ]
https://www.ms.u-tokyo.ac.jp/~shiho/spparis/index.html

2021/03/11

Information Mathematics Seminar

16:50-18:35   Online
Akiyoshi Sannai (RIKEN)
Deep learning with symmetry (Japanese)
[ Abstract ]
Explanation on deep learning with symmetry
[ Reference URL ]
https://docs.google.com/forms/d/1yIKNrwSLsdYt_rivZI8JxhIu3kWtJua5hG8nV5FYbCk/

Tokyo-Nagoya Algebra Seminar

16:00-17:30   Online
Please see the URL below for details on the online seminar.
Akihito Wachi (Hokkaido University of Education)
相対不変式で生成されるゴレンスタイン環のレフシェッツ性 (Japanese)
[ Reference URL ]
http://www.math.nagoya-u.ac.jp/~aaron.chan/TNAseminar.html

2021/03/10

Number Theory Seminar

17:00-18:00   Online
Katsuyuki Bando (University of Tokyo)
Geometric Satake equivalence in mixed characteristic and Springer correspondence (Japanese)
[ Abstract ]
The geometric Satake correspondence is an equivalence between the category of equivariant perverse sheaves on the affine Grassmannian and the category of representations of the Langlands dual group. It is known that there is a mixed characteristic version of the geometric Satake correspondence. The Springer correspondence is a correspondence between the category of equivariant perverse sheaves on the nilpotent cone and the category of representation of the Weyl group. In this talk, we will explain some relation between these two correspondences, including the mixed characteristic case.

2021/02/24

Tokyo-Nagoya Algebra Seminar

16:00-17:30   Online
Please see the URL below for details on the online seminar.
Shunya Saito (Nagoya University)
周期三角圏上の傾理論 (Japanese)
[ Reference URL ]
http://www.math.nagoya-u.ac.jp/~aaron.chan/TNAseminar.html

2021/02/18

Operator Algebra Seminars

16:45-18:15   Online
Sebastiano Carpi (Univ. Rome, "Tor Vergata")
Conformal nets from positive energy representations of the Zamolodchikov $W_3$ algebra with central charge greater than or equal to two (English)
[ Reference URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm

2021/02/17

Seminar on Probability and Statistics

14:30-15:30   Room #Zoom (Graduate School of Math. Sci. Bldg.)
Register at least 3 days before at the reference URL. The URL for participation sent before the seminar.
Nakahiro Yoshida (University of Tokyo)
Quasi-likelihood analysis for stochastic differential equations: volatility estimation and global jump filters (ENGLISH)
[ Abstract ]
Asia-Pacific Seminar in Probability and Statistics https://sites.google.com/view/apsps/home

The quasi likelihood analysis (QLA) is a framework of statistical inference for stochastic processes, featuring the quasi-likelihood random field and the polynomial type large deviation inequality. The QLA enables us to systematically derive limit theorems and tail probability estimates for the associated QLA estimators (quasi-maximum likelihood estimator and quasi-Bayesian estimator) for various dependent models. The first half of the talk will be devoted to an introduction to the QLA for stochastic differential equations. The second half presents recent developments in a filtering problem to estimate volatility from the data contaminated with jumps. A QLA for volatility for a stochastic differential equation with jumps is constructed, based on a "global jump filter" that uses all the increments of the process to decide whether an increment has jumps.


Key words: stochastic differential equation, high frequency data, Le Cam-Hajek theory, Ibragimov-Has'minskii-Kutoyants program, polynomial type large deviation inequality, quasi-maximum likelihood estimator, quasi-Bayesian estimator, L^p-estimates of the error, non-ergodic statistics, asymptotic (mixed) normality.
[ Reference URL ]
https://docs.google.com/forms/d/e/1FAIpQLSeLrq_Ifc4WvJC6uvwIpMyrAVM9v-0J3FOaZbsplbU9d21ALw/viewform

2021/02/10

Tokyo-Nagoya Algebra Seminar

16:00-17:30   Online
Please see the URL below for details on the online seminar.
Akishi Ikeda (Josai University)
Gentle代数の2重次数付きCalabi-Yau完備化と曲面の幾何学 (Japanese)
[ Reference URL ]
http://www.math.nagoya-u.ac.jp/~aaron.chan/TNAseminar.html

2021/02/04

Information Mathematics Seminar

16:50-18:35   Online
Yuya O. Nakagawa (QunaSys Inc.)
Quantum chemistry calculations and material simulations by quantum computers (Japanese)
[ Abstract ]
Explanation on quantum chemistry calculations and material simulations by quantum computers
[ Reference URL ]
https://docs.google.com/forms/d/1yIKNrwSLsdYt_rivZI8JxhIu3kWtJua5hG8nV5FYbCk/

2021/01/29

thesis presentations

9:15-10:30   Online
NAKATSUKA Shigenori (Graduate School of Mathematical Sciences University of Tokyo)
Feigin-Semikhatov conjecture and its applications
(Feigin-Semikhatov予想とその応用)
[ Reference URL ]
https://forms.gle/bdsntP4pZ4TMaehF9

thesis presentations

11:00-12:15   Online
MORIWAKI Yuto (Graduate School of Mathematical Sciences University of Tokyo)
Two-dimensional conformal field theory, current-current deformation and mass formula
(二次元共形場理論のカレントカレント変形と重み公式)
[ Reference URL ]
https://forms.gle/bdsntP4pZ4TMaehF9

thesis presentations

9:15-10:30   Online
KANNAKA Kazuki (Graduate School of Mathematical Sciences University of Tokyo)
Spectral analysis on complete anti-de Sitter 3-manifolds
(完備な3次元反ド・ジッター多様体上のスペクトル解析)
[ Reference URL ]
https://forms.gle/bdsntP4pZ4TMaehF9

thesis presentations

11:00-12:15   Online
KIMURA Mitsuaki (Graduate School of Mathematical Sciences University of Tokyo)
Bounded cohomology of volume-preserving diffeomorphism groups
(体積保存微分同相群の有界コホモロジー)
[ Reference URL ]
https://forms.gle/bdsntP4pZ4TMaehF9

2021/01/28

Operator Algebra Seminars

16:45-18:15   Online
James Tener (Australian National Univ.)
Finite-index subfactors and rational conformal field theory (English)
[ Reference URL ]
https://www.ms.u-tokyo.ac.jp/~yasuyuki/tokyo-seminar.htm

thesis presentations

9:15-10:30   Online
MORI Michiya (Graduate School of Mathematical Sciences University of Tokyo)
On the geometry of projections of von Neumann algebras
( von Neumann 環の射影束の幾何構造について )
[ Reference URL ]
https://forms.gle/bdsntP4pZ4TMaehF9

thesis presentations

11:00-12:15   Online
KITAOKA Wataru (Graduate School of Mathematical Sciences University of Tokyo)
Ray-Singer torsion and the Laplacians of the Rumin complex on lens spaces
(レンズ空間上のRay-Singer捩率とRumin複体のラプラシアン)
[ Reference URL ]
https://forms.gle/bdsntP4pZ4TMaehF9

thesis presentations

13:00-14:15   Online
SUDA Hayate (Graduate School of Mathematical Sciences University of Tokyo)
SCALING LIMITS OF STOCHASTIC HARMONIC CHAINS WITH LONG-RANGE INTERACTIONS
(長距離相関を持つ確率調和振動子鎖に対するスケール極限)
[ Reference URL ]
https://forms.gle/bdsntP4pZ4TMaehF9

thesis presentations

14:45-16:00   Online
MUKAI Asato (Graduate School of Mathematical Sciences University of Tokyo)
Asymptotic analysis for solutions to semilinear heat equations
(半線形熱方程式の解に対する漸近解析)
[ Reference URL ]
https://forms.gle/bdsntP4pZ4TMaehF9

thesis presentations

11:00-12:15   Online
INATSUGU Haruhiko (Graduate School of Mathematical Sciences University of Tokyo)
Statistical Inference for Stochastic Differential Equations with Jumps:Global Filtering Approach
(ジャンプを含む確率微分方程式に対する統計推測:
大域的フィルターによる方法)
[ Reference URL ]
https://forms.gle/bdsntP4pZ4TMaehF9

thesis presentations

9:15-10:30   Online
SUZUKI Masamitsu (Graduate School of Mathematical Sciences University of Tokyo)
Local in time solvability for reaction-diffusion systems with rapidly growing nonlinear terms
(速く増大する非線形項を持つ連立反応拡散方程式の時間局所可解性)
[ Reference URL ]
https://forms.gle/bdsntP4pZ4TMaehF9

< Previous 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190 Next >