iTHEMS Math Seminar

Seminar

iTHEMS Math Seminar

An introduction to modular functions, conformal field theories, and moonshine phenomena

July 2 at 16:00 - 18:10, 2021

Mr. Mizuki Oikawa (Junior Research Associate, iTHEMS)

Moonshine phenomena are certain mysterious connections between modular functions and finite groups. The first example is the celebrated monstrous moonshine, which connects the J-invariant and the Mons...more

Venue: via Zoom

Event Official Language: English

Seminar

iTHEMS Math Seminar

Stable eigenvalues of compact anti-de Sitter 3-manifolds

June 18 at 16:00 - 18:10, 2021

Dr. Kazuki Kannaka (Special Postdoctoral Researcher, iTHEMS)

Geometric objects that have been investigated in detail so far, such as closed Riemann surfaces, are sometimes locally homogeneous. Loosely speaking, their infinitesimal behavior is the same at each p...more

Venue: via Zoom

Event Official Language: English

Seminar

iTHEMS Math Seminar

Loewner's theorem for maps on operator domains / The structure of maps on the space of all quantum pure states that preserve a fixed quantum angle

May 24 at 16:00 - 18:10, 2021

Dr. Michiya Mori (Special Postdoctoral Researcher, iTHEMS)

This talk is divided into two independent topics. In the first part of my talk we consider the order structure of hermitian matrices. Given two matrix domains (open connected sets of n-by-n hermitia...more

Venue: via Zoom

Event Official Language: English

Seminar

iTHEMS Math Seminar

Geometry of canonical metrics on Kähler manifolds

May 14 at 16:00 - 18:10, 2021

Dr. Eiji Inoue (Special Postdoctoral Researcher, iTHEMS)

The aim of this talk is to report recent trends in Kähler geometry. Kähler geometry consists of two aspects: the one is algebraic geometry and the other is metric geometry.The first one hour is an int...more

Venue: via Zoom

Event Official Language: English

Seminar

iTHEMS Math Seminar

Alternative tsunami observing and forecasting systems

April 22 at 16:00 - 18:10, 2021

Dr. Iyan Mulia (Research Scientist, Prediction Science Laboratory, RIKEN CPR)

Dedicated tsunami observing systems are mostly expensive and are often not sustainable. Therefore, alternative approaches should be implemented to overcome the issues. We introduced innovative ways to...more

Venue: via Zoom

Event Official Language: English

Seminar

iTHEMS Math Seminar

Long-time behavior of moving solids in a fluid and the kinetic theory of gases

April 7 at 16:00 - 18:10, 2021

Dr. Kai Koike (JSPS Fellow, Graduate School of Engineering, Kyoto University)

Understanding dynamics of solids in a fluid is a fundamental problem in fluid dynamics. Due to the growing interest in engineering in out-of-equilibrium situations, moving boundary problems for kineti...more

Venue: via Zoom

Event Official Language: English

Seminar

iTHEMS Math Seminar

The Green-Tao theorem for number fields

March 22 at 16:00 - 18:10, 2021

Dr. Wataru Kai (Assistant professor, Mathematical Institute, Tohoku University)

5, 11, 17, 23, 29 are prime numbers which form an arithmetic progression of length 5. A famous theorem of Ben Green and Terence Tao in 2008 says there are arbitrarily long arithmetic progressions of p...more

Venue: via Zoom

Event Official Language: English

Seminar

iTHEMS Math Seminar

Scattering theory for half-line Schrödinger operators: analytic and topological results

December 7 at 16:00 - 18:10, 2020

Dr. Hideki Inoue (Nagoya University)

Levinson’s theorem is a surprising result in quantum scattering theory, which relates the number of bound states and the scattering part of the underlying quantum system. For the last about ten years,...more

Venue: via Zoom

Event Official Language: English

Seminar

iTHEMS Math Seminar

Flat and spherical surface approximations

November 30 at 16:00 - 17:30, 2020

Dr. Martin Skrodzki (Visiting Researcher, iTHEMS / Fellow, German Academic Scholarship Foundation)

State-of-the-art acquisition devices produce surface representations of increasingly high resolution. While these detailed representations are important for production, they are problematic e.g. when ...more

Venue: via Zoom

Event Official Language: English

Seminar

iTHEMS Math Seminar

Representations of fundamental groups and 3-manifold topology

November 16 at 16:00 - 18:10, 2020

Dr. Takahiro Kitayama (Associate Professor, Graduate School of Mathematical Sciences, The university of Tokyo)

In 3-dimensional topology the great progress during the last two decades revealed that various properties of 3-manifolds are well understood from their fundamental groups. I will give an introduction ...more

Venue: via Zoom

Event Official Language: English

Seminar

iTHEMS Math Seminar

Efficient probabilistic assessment of building performance: sequential Monte Carlo and decomposition methods

November 13 at 16:00 - 18:10, 2020

Dr. Tianfeng Hou (Postdoctoral Researcher, iTHEMS / Postdoctoral Researcher, Prediction Science Laboratory, RIKEN Cluster for Pioneering Research / Postdoctoral Researcher, Data Assimilation Research Team, RIKEN Center for Computational Science)

The use of numerical simulations for complex systems is common. However, significant uncertainties may exist for many of the involved variables, and in order to ensure the reliability of our simulatio...more

Venue: via Zoom

Event Official Language: English

Seminar

iTHEMS Math Seminar

Mathematical aspects of quasi-Monte Carlo integration

November 5 at 16:00 - 18:10, 2020

Dr. Kosuke Suzuki (Assistant Professor, Graduate School of Advanced Science and Engineering, Hiroshima University)

In this talk, I will introduce mathematical aspects of quasi-Monte Carlo (QMC) integration. We aim to approximate the integral of a function on the d-dimensional hypercube [0,1]^d. A useful approach i...more

Venue: via Zoom

Event Official Language: English

Seminar

iTHEMS Math Seminar

Math Seminars by Dr. Genki Ouchi and Dr. Kenta Sato

September 24 at 16:00 - 18:10, 2020

Dr. Genki Ouchi (Special Postdoctoral Researcher, iTHEMS)
Dr. Kenta Sato (Special Postdoctoral Researcher, iTHEMS)

[Talk 1] (16:00 - 17:00) Dr. Genki Ouchi Automorphism groups of cubic fourfolds and K3 categories In this talk, I would like to talk about symmetries of algebraic varieties, especially cubic fou...more

Venue: via Zoom

Event Official Language: English

Seminar

iTHEMS Math Seminar

Maximal Regularity and Partial Differential Equations.

September 8 at 16:00 - 18:10, 2020

The theory of maximal regularity is a powerful tool to get solutions having the best regularity to linear partial differential equations (PDEs) of parabolic type. The theory is also applicable to show...more

Venue: via Zoom

Event Official Language: English

Seminar

iTHEMS Math Seminar

Stability of ferromagnetism in many-electron systems

July 31 at 16:00 - 18:10, 2020

Prof. Tadahiro Miyao (Associate Professor, Department of Mathematics, Faculty of Science, Hokkaido University)

First part Title: Stability of ferromagnetism in many-electron systems Abstract: I construct a model-independent framework describing stabilities of ferromagnetism in strongly correlated electron...more

Venue: via Zoom

Event Official Language: English

Seminar

iTHEMS Math Seminar

Topological data analysis from a practical and mathematical perspective

July 15 at 16:00 - 18:10, 2020

Dr. Yuichi Ike (Researcher, Artificial Intelligence, FUJITSU LABORATORIES LTD.)

1. Topological data analysis and its applications In this talk, I will explain some methods in topological data analysis (TDA) and their applications. First I recall persistent homology, which is a ...more

Venue: via Zoom

Event Official Language: English

Seminar

iTHEMS Math Seminar

Universal Error Bound for Constrained Quantum Dynamics

June 24 at 16:00 - 18:10, 2020

Dr. Ryusuke Hamazaki (Senior Research Scientist, iTHEMS / RIKEN Hakubi Team Leader, Nonequilibrium Quantum Statistical Mechanics RIKEN Hakubi Research Team, RIKEN Cluster for Pioneering Research)

In quantum mechanics, the existence of large energy gaps allows us to trace out the degrees of freedom of irrelevant energy scale. Consequently, we can treat a system within a constrained subspace obt...more

Venue: via Zoom

Event Official Language: English

Seminar

iTHEMS Math Seminar

Information geometry of operator scaling

June 17 at 16:00 - 18:10, 2020

Dr. Tasuku Soma (Research Associate, Graduate School of Information Science and Technology, The University of Tokyo)

Matrix scaling is a classical problem with a wide range of applications. It is known that the Sinkhorn algorithm for matrix scaling is interpreted as alternating e-projections from the viewpoint of cl...more

Venue: via Zoom

Event Official Language: English

Seminar

iTHEMS Math Seminar

Knotted 2-spheres in the 4-space and Yang-Mills gauge theory

May 27 at 16:00 - 18:10, 2020

Dr. Masaki Taniguchi (Special Postdoctoral Researcher, iTHEMS)

The classification problem of knots is one of the central topics in a study of topology. In the first part, we review classical knot theory and theory of 2-dimensional knots in the 4-dimensional space...more

Venue: via Zoom

Event Official Language: English

Seminar

iTHEMS Math Seminar

How many electrons can atoms bind?

May 13 at 16:00 - 18:10, 2020

Dr. Yukimi Goto (Special Postdoctoral Researcher, iTHEMS)

In this talk, I will introduce the mathematical studies on the ionization problem. Some experimental & numerical evidences say that any doubly charged atomic ion X^{2-} is not stable. This 'fact' is c...more

Venue: via Zoom

Event Official Language: English