# Announcement

## Two Senior Visiting Scientists jointed iTHEMS

2019-11-07

It is our great pleasure to announce that two Senior Visiting Scientists have joined iTHEMS from Nov.1, 2019.

Prof. Takashi Sakajo (Kyoto Univ.) whose research fields are applied mathematics and mathematical fluid dynamics.

He is in charge of the SUURI-COOL Kyoto.

Prof. Hidetoshi Nishimori (Tokyo Institute of Technology) whose research fields are statistical mechanics and quantum computation.

He is one of the founding members of the iTHEMS QCoIn working group.

# Hot Topic

## iTHEMS Coffee Meeting continues

2019-11-08

Every Friday, we have iTHEMS coffee meeting from 12:30, where somebody is asked to give a 15 min. lecture on a specific topic for non-experts by using our jumbo blackboard.

On Oct.25, 2019, Ivan Kostov (CEA-Saclay) gave a 15 min. lecture on integrability in quantum field theory by drawing s multi-particle scattering diagram for elementary particles living in 2 space-time dimensions.

On Nov.1, 2019, Pascal Naidon (RIKEN Nishina Center) gave a 15 min. lecture on the quantum physics of Efimov effect by using his handmade Borromean rings (three entangled ribbons which is a classical analogue of the Efimov effect).

# Seminar Report

## Math Seminar talks by Dr. Ken Shiozaki

2019-11-01

The iTHEMS Math seminar was held on 24 Oct., inviting Ken Shiozaki from Kyoto university. The title of the talk was "Atiyah-Hirzebruch spectral sequence in band theory". The main subject of the talk was topological K-theory, a branch of topology in mathematics, from the viewpoint of physics. In the theory of condensed matter physics, it is well-understood that a classification of topological phases is given by topological (twisted equivariant) K-theory. Conversely, some physical intuitions help us understanding (or even calculating) K-theory. In the talk, the speaker illustrated "physical meanings" of basic mathematical notions such as the axioms of cohomology theory, the Mayer-Vietoris exact sequence and the Bott periodicity.

Atiyah-Hirzebruch spectral sequence in the band theory

October 24 at 16:00 - 18:10, 2019

# Upcoming Events

## Workshop

### Collaborative Meeting on Supernova Remnants between Japan and USA

November 7 - 12, 2019

The aim of the workshop is to bring together experts on supernova remnants and related topics for active discussions and to initiate possible collaborations among the participants.

The workshop will be held at RIKEN Wako campus (first week, Nov. 7th and 8th) and Kyoto University (second week, Nov. 11th and 12th).

This workshop is supported by iTHEMS (RIKEN Interdisciplinary Theoretical and Mathematical Sciences Program) and r-EMU (RIKEN Pioneering Project:Evolution of Matter in the Universe).

Venue: Okochi Hall, 1F Laser Science Laboratory, RIKEN / 224-226, Main Research Building / SUURI-COOL (Kyoto), #204-205, 2F Maskawa Building for Education and Research, North Campus, Kyoto University

Event Official Language: English

## Seminar

### Some topics in projective geometry of algebraic varieties

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

Dr. Atsushi Ito (Assistant Professor, Nagoya 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 bit more detailed talk for mathematicians (working in other areas). We welcome you joining both parts of the seminar or only the first/second half.

Venue: Seminar Room #160, 1F Main Research Building, RIKEN

Event Official Language: English

## Lecture

### RIKEN Open Campus in Kobe

November 9 at 10:00 - 16:30, 2019

Dr. Takumi Doi (Senior Research Scientist, iTHEMS / Senior Research Scientist, Quantum Hadron Physics Laboratory, RIKEN Nishina Center for Accelerator-Based Science (RNC))

RIKEN Open Campus in Kobe will be held on Nov.9, 2019.

Dr. Emiko Hiyama (Kyushu Univ.) and Dr. Takumi Doi (Nishina Center / iTHEMS) will give lectures on computational nuclear and particle physics at Kobe IIB building where SUURI-COOL Kobe is located. Please inform the news to anybody who are interested in visiting RIKEN Kobe.

Venue: Integrated Innovation Building (IIB), Kobe Campus, RIKEN

Event Official Language: Japanese

## Seminar

### Variational methods in quantum annealing

November 15 at 13:30 - 15:00, 2019

Dr. Shunji Matsuura (Fundamental Researcher, Quantum Simulation Division, 1QBit, Canada)

Venue: #433, Main Research Building, RIKEN

Event Official Language: English

## Colloquium

### The 10th MACS Colloquium

November 15 at 14:45 - 18:45, 2019

Dr. Nami Sakai (Chief Scientist, Star and Planet Formation Laboratory, RIKEN Cluster for Pioneering Research (CPR))

Prof. Kazuya Watanabe (Professor, Graduate School of Science, Kyoto University)

14:45- Teatime

15:00- Talk by Dr. Nami Sakai

16:15- Talk by Prof. Kazuya Watanabe

17:45- Discussion

The 10th MACS colloquium supported by iTHEMS. It will be broadcasted to Wako, but if you can join the colloquium physically in Kyoto, that would be better. iTHEMS provides good confectionery at Kyoto!

Venue: Lecture room #401, Graduate School of Science Building No 6, Kyoto University

Event Official Language: Japanese

## Seminar

### A multiscale study of turbulent heating in hot accretion flows

November 18 at 14:00 - 15:00, 2019

Dr. Yohei Kawazura (Assistant Professor, Tohoku University)

Venue: #132, 1F, Main Research Building, RIKEN

Event Official Language: English

## Workshop

### RIKEN-Kyushu workshop on particle, nuclear and astrophysics

December 23 - 24, 2019

Organizers

Emiko Hiyama (Kyushu U./RIKEN)

Hiroshi Suzuki (Kyushu U.)

Tetsuo Hatsuda (RIKEN)

Venue: Faculty of Science, Ito Campus, Kyushu University

Event Official Language: Japanese

# Upcoming Visitor

November 13 - 27, 2019 ## Prof. Catherine BeaucheminSenior Visiting Scientist, iTHEMS / Professor, Department of Physics, Ryerson University, Canada Research fields: Virophysics Visiting Place: 231, Main Research Building |

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