Interdisciplinary Theoretical and Mathematical Sciences Program (iTHEMS) is an international research program at RIKEN. It facilitates close collaborations among researchers from different disciplines in theoretical, mathematical and computational sciences. The ultimate goal of iTHEMS is to unravel the mystery of the Universe, matter, and life, as well as to solve key problems in modern society through interdisciplinary approaches.

## Upcoming Events

Today

### Directional dark matter search and the technologies

December 3 at 10:00 - 11:00, 2020

Dr. Tatsuhiro Naka (Lecturer, Department of Physics, Toho University / Specially Appointed Assistant Professor, Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI), Nagoya University)

*Detailed information about the seminar refer to the email.

Venue: via Zoom

Event Official Language: English

Today

### KPZ equation, attractive bosons, and the Efimov effect

December 3 at 13:00 - 14:30, 2020

Dr. Yusuke Nishida (Associate Professor, Department of Physics, Tokyo Institute of Technology)

The Kardar-Parisi-Zhang (KPZ) equation for surface growth has been a paradigmatic model in nonequilibrium statistical physics. In particular, it in dimensions higher than two undergoes a roughening tr...more

Venue: via Zoom

Event Official Language: English

Tomorrow

### Toward the Practical Use of Quantum Computers

December 4 at 10:30 - 12:00, 2020

Dr. Shunji Matsuura (Visiting Scientist (Industry), iTHEMS)

量子コンピュータは古典コンピュータとは異なる原理に基づいて動いており、自然科学を含む様々な分野において大きな変化をもたらすと考えられている。特にこの数年の進展は著しく、量子計算の古典計算に対する優位性が実験的に初めて示されるなど、期待されているマイルストーンが着実に達成されていっている。一方で量子コンピュータの発展において常に障害となっているのがノイズである。量子状態はノイズの影響を受けやすく、現...more

Venue: via Zoom

Event Official Language: Japanese

### Presented by iTHEMS & academist - Do you really know what the black hole is?

December 6 at 14:00 - 16:00, 2020

Dr. Shigehiro Nagataki
(Deputy Program Director, iTHEMS)

Dr. Yoshiyuki Inoue
(Senior Visiting Scientist, iTHEMS)

Dr. Yuki Yokokura
(Senior Research Scientist, iTHEMS)

–From the latest theories and observations to the explanation of the Nobel Prize in Physics! An introduction to black holes from active physicists– The 2020 Nobel Prize in Physics was awarded to Si...more

Venue: via Online

Event Official Language: Japanese

### 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

### Geometry (形); Inconspicuous regulator that determines the fate of cells

December 14 at 10:00 - 11:30, 2020

Prof. Sungrim Seirin-Lee (Professor, Hiroshima University)

December 14 at 10:00-11:30, 2020 (JST) December 13 at 20:00-21:30, 2020 (EST) In the history of mathematical study in pattern formation, the effect of domain has been considered as an important fa...more

Venue: via Zoom

Event Official Language: English

### Classical liquids and functional renormalization group

December 17 at 13:00 - 14:30, 2020

Dr. Takeru Yokota (Postdoctoral Researcher, Institute for Solid State Physics, The University of Tokyo)

Development of methods for classical statistical mechanics is desired for accurate predictions of the structures and thermodynamic properties of liquids. A powerful framework to describe classical liq...more

Venue: via Zoom

Event Official Language: English

## Opportunities

### Seeking a Postdoctoral Researcher (W20086) *theoretical physics

Deadline: Open until filled

iTHEMS is seeking a postdoctoral researcher in theoretical physics including condensed matter physics, particle physics and nuclear physics. In particular, the successful applicant is expected to help develop an adiabatic quantum computer (AQC) simulator using time-dependent density matrix renormalization group (DMRG). This project is part of a greater effort in the Berkeley area towards exploring the efficacy of adiabatic quantum computing supported jointly by RIKEN, UC Berkeley, Lawrence Berkeley Lab, and the U.S. Department of Energy. In addition to developing the AQC simulator, the candidate will have the opportunity to pursue top-level research in collaboration with an interdisciplinary group of researchers across fields such as mathematics, physics, chemistry, life sciences, engineering computational sciences, information sciences, and social sciences at iTHEMS, and physics, mathematics and computational sciences at Berkeley.

### Seeking a Research Scientist or Senior Research Scientist (W20095) *extreme universe

Deadline: Open until filled

iTHEMS is seeking theorist(s) working on extreme universe including high-energy astrophysics, supernovae, neutron stars, black holes, and early universe. Successful applicant(s) are expected not only to pursue top-level researches in astrophysics but also to lead interdisciplinary collaborations among different fields such as mathematics, physics, chemistry, life sciences, engineering, computational sciences, information sciences, and social sciences, under the concept of iTHEMS. Also, successful applicant(s) are expected to participate in the international collaboration on astrophysics between iTHEMS and the NSF Physics Frontier Center in UC Berkeley established on Sept. 2020.

### Seeking a Postdoctoral Researcher (W20122) *ecology and evolutionary biology

Deadline: Open until filled

iTHEMS is seeking postdoctoral researcher(s) in the field of ecology and evolutionary biology (including population genetics, epidemiology, quantitative biology, and bioinformatics). Successful applicant(s) are expected to not only pursue high quality research in their own field but also promote interdisciplinary collaborations among different fields such as mathematics, physics, chemistry, life sciences, engineering, computational sciences, information sciences, and social sciences, under the concept of iTHEMS. This time, we encourage early-career applicants who have a high research potential in pursuing collaboration with Dr. Ryosuke Iritani (ecology and evolution) as well as various iTHEMS-researchers across disciplines. Though your research backgrounds in population-/community-dynamics, stochastic analysis, evolutionary game theory, and stochastic simulations are highly beneficial, we value your research proposal (concreteness, logicality, and realizability of your future plans) more than your past achievements.

### Seeking a Postdoctoral Researcher (W20157) *physics of dynamical systems

Deadline: Open until filled

iTHEMS is seeking a postdoctoral researcher to work closely with Catherine Beauchemin in the field of physics of dynamical systems; primarily applied to virophysics. Work will primarily consist in constructing mathematical and computer models describing the dynamics of a viral infection within a host (in vivo) or a cell culture (in vitro). The models are validated against or applied to experimental infection data (e.g., daily virus concentration levels collected over the course of the infection) using Bayesian parameter estimation via a Markov chain Monte Carlo method. The projects are not experimental in nature: the data used in our research is gathered elsewhere by our collaborators or is taken from the literature. Ideal candidates will hold a PhD in Physics (computational, quantum, particle, astro, theoretical) or Applied Mathematics, and have excellent written English skills. No experience with anything to do with biology or virology is required or expected. Fellows should possess programming skills in python (preferably) or C/C++, Octave/Matlab, should already be familiar with or willing to learn the typesetting language LaTeX, be comfortable with a Linux operating system, and have experience in implementing and solving ordinary and partial differential equation systems or cellular automata/agent-based systems.

### Seeking a Postdoctoral Researcher (W20090) *mathematical sciences

Deadline: December 14, 2020

iTHEMS is seeking postdoctoral researcher(s) in the field of mathematical sciences (including pure mathematics and applied mathematics). Successful applicant(s) are expected not only to pursue top-level researches in their own field but also to promote interdisciplinary collaborations among different fields such as mathematics, physics, chemistry, life sciences, engineering, computational sciences, information sciences, and social sciences, under the concept of iTHEMS. This time, we encourage junior applicants who have high research potential in the field of mathematical sciences, who can actively communicate with researchers in iTHEMS. iTHEMS has a senior research scientist, Dr. Hiroyasu Miyazaki (arithmetic/algebraic geometry), and researchers from various field of mathematical sciences, including analysis, partial differential equations, topology, gauge theory, mathematical physics, etc.

## Latest News

2020-11-30

### Biology Seminar by Dr. Hidenori Tanaka on November 20, 2020

In iTHEMS Biology Seminar on November 20th, Dr. Hidenori Tanaka (Physics & Informatics Laboratories, NTT Research) gave us an exciting talk about physics principles in neural networks. He first review...more

2020-11-26

### Week 4 of November

Title: Motives with modulus, III: The categories of motives Author: Bruno Kahn, Hiroyasu Miyazaki, Shuji Saito, Takao Yamazaki arXiv: http://arxiv.org/abs/2011.11859v1 Title: Scale setting the M{...more

2020-11-26

### Dr. Yuki Yazaki received "2020 The Encouragement Award for Young Protistologists"

It is our great pleasure to inform you that our iTHEMS colleague, Yuki Yazaki received "2020 The Encouragement Award for Young Protistologists" (日本原生生物学会奨励賞) from "Japan Society of Protistology (日本原生生...more