# 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

Event Official Language: English

## Flat and spherical surface approximations

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

Dr. Martin Skrodzki (Visiting Researcher, iTHEMS)

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

## 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

## 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)

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

## 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

## 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

## 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

## 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

## 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

## Universal Error Bound for Constrained Quantum Dynamics

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

Dr. Ryusuke Hamazaki (Senior Research Scientist, iTHEMS)

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

## 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

## 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

## 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

## From Eigenvalues to Resonances

May 1 at 16:00 - 18:10, 2020

Dr. Keita Mikami (Research Scientist, iTHEMS)

Resonance is one of the most studied object in mathematical study of Schrödinger operators. One possible reason is that resonance is appeared in many other fields like arithmetic, physics, and topogra...more

Venue: via zoom

Event Official Language: English

## Index of the Wilson-Dirac operator revisited: a discrete version of Dirac operator on a finite lattice

February 25 at 16:00 - 18:10, 2020

Dr. Mikio Furuta (Professor, The University of Tokyo)

Venue: Seminar Room #160

Event Official Language: English

## Solved and open problems regarding the neighborhood grid data structure

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

Dr. Martin Skrodzki (Visiting Researcher, iTHEMS)

February 7 at 16:00-17:00 17:10-18:10, 2020

Venue: Seminar Room #160

Event Official Language: English

## Semiclassical methods in mathematical quantum mechanics

January 23 at 16:00 - 18:10, 2020

Dr. Shu Nakamura (Professor, Gakushuin University)

Plan of the seminar: we separate each talk into two. In the first 60 minutes the speaker gives an introductory talk for non-mathematicians. After a short break, the second 60 minutes is spent for a b...more

Venue: #435-437, Main Research Building

Event Official Language: English

## Multiple Zeta Values: Interrelation of Series and Integrals

December 17 at 16:00 - 18:10, 2019

Prof. Syuji Yamamoto (Associate Professor, Keio University)

Plan of the seminar: we separate each talk into two. In the first 60 minutes the speaker gives an introductory talk for non-mathematicians. After a short break, the second 60 minutes is spent for a b...more

Venue: Seminar Room #160

Event Official Language: English

## Noncommutative crepant resolutions and some higher dimensional flops

December 4 at 16:00 - 18:10, 2019

Dr. Wahei Hara (JSPS Research Fellow, School of Science and Engineering, Waseda University)

Plan of the seminar: we separate each talk into two. In the first 60 minutes the speaker gives an introductory talk for non-mathematicians. After a short break, the second 60 minutes is spent for a b...more

Venue: Seminar Room #160

Event Official Language: English

## Some topics in projective geometry of algebraic varieties

November 8 at 16:00 - 18:10, 2019

Dr. Atsushi Ito (Assistant Professor, Nagoya University)

Venue: Seminar Room #160

Event Official Language: English