iTHEMS Weekly News Letter

Seminar Report

Biology Seminar by Dr. Hye Jin Park on September 16, 2020

2020-09-18

On 16th September, Hye Jin Park (Asia Pacific Center for Theoretical Physics; APCTP) gave us a talk about her work on eco-evolutionary dynamics. She specifically looked at what if there are novel mutations that generate a nonexistent phenotype (temporal emergence of different phenotypes) and how it affects the evolution of cyclic dominance. She took advantage of introducing novel phenotypes to construct phylogenetic-alike trees, which contain some information for which types are similar or dissimilar. She found that similar types are unlikely to exhibit cyclic dominance. We discussed how we can apply the theory to real systems and what factors are important. Thank you so much, Hye Jin for the fantastic talk!
-Ryosuke Iritani

Upcoming Events

External Event

Perspective of nuclear physics in the 21 century

September 27 at 13:30 - 17:00, 2020

Dr. Tetsuo Hatsuda (Program Director, iTHEMS)
Prof. Hiroyoshi Sakurai (Director, RIKEN Nishina Center for Accelerator-Based Science (RNC))
Prof. Naohito Saito (Director, J-PARC Center)
Prof. Takaaki Kajita (Director, The Institute for Cosmic Ray Research (ICRR), The University of Tokyo)

世界最先端の日本の原子核物理研究を行う4施設の牽引者がそれぞれリレー方式で講義を行います。21世紀の原子核物理学の潮流といえる、重力波や中性子星連星合体など宇宙の謎に迫る高密度世界の解明に関する研究内容から、先端加速器やスーパーコンピューターを用いた最先端の研究スタイルまで、日本が誇る原子核物理学の今と今後の展望をお話します。

Venue: via YouTube Live

Event Official Language: Japanese

External Event

Dr. Don Warren thumbnail

Fast Radio Bursts: a cosmic mystery

September 28 at 10:30 - 11:00, 2020

Dr. Don Warren (Research Scientist, iTHEMS)

On Monday morning, iTHEMS researcher Don Warren will give a public talk on fast radio bursts. He will describe this cosmic mystery, and reveal how impatient Australians play an important role in the story. This talk is part of the global Stream You series, hosted by National Geographic and Nerd Nite. Don’s talk begins at 10:30am, but there will be three talks before his starting at 9:00am. To watch Don’s talk, or any of the others, visit facebook.com/nerdnite on Monday and look for the YouTube link.

Venue: via Online

Event Official Language: English

Workshop

The Second Tohoku University - RIKEN Joint Workshop:

Co-hosted by iTHEMS

The Second Tohoku University - RIKEN Joint Workshop: "Math Meets Quantum Materials"

September 29 - 30, 2020

Prof. Hidetoshi Nishimori (Senior Visiting Scientist, iTHEMS / Specially Appointed Professor, Tokyo Institute of Technology)
Dr. Tomoki Ozawa (Visiting Scientist, iTHEMS / Associate Professor, Advanced Institute for Materials Research (AIMR), Tohoku University)
Dr. Ching-Kai Chiu (Senior Research Scientist, iTHEMS)
Dr. Ryusuke Hamazaki (Senior Research Scientist, iTHEMS / RIKEN Hakubi Team Leader, Nonequilibrium Quantum Statistical Mechanics RIKEN Hakubi Research Team, RIKEN Cluster for Pioneering Research)
Dr. Kyosuke Adachi (Special Postdoctoral Researcher, iTHEMS / Special Postdoctoral Researcher, Nonequilibrium Physics of Living Matter RIKEN Hakubi Research Team, RIKEN Center for Biosystems Dynamics Research)
Prof. Christopher Bourne (Visiting Scientist, iTHEMS / Assistant Professor, Advanced Institute for Materials Research (AIMR), Tohoku University)

The second Tohoku University - RIKEN joint workshop, entitled "Math Meets Quantum Materials," takes place from September 29 - 30.

Tohoku University and RIKEN have been holding a series of joint workshops based on the agreement on collaboration and cooperation signed in 2019.

The second workshop focuses on collaboration in the fields of mathematical sciences and quantum materials; two fields that have significantly merged in recent years.

Like topological materials, which are discovered using the mathematical concept of topology, materials science is currently evolving from the conventional way of finding materials. Instead of developing materials with good properties through numerous experiments, materials science is increasingly finding materials using mathematical predictions.

This workshop will discuss these latests developments and related topics.
Although some lectures will take place in Japanese, the majority of talks will be in English.
The deadline for registration is Monday, September 28.

For more information, please click on the relevant link.

Venue: via Online

Event Official Language: English

Lecture

Public Lecture : Math meets Quantum Materials thumbnail

Co-hosted by iTHEMS

Public Lecture : Math meets Quantum Materials

September 29 at 19:00 - 20:30, 2020

Prof. Hidetoshi Nishimori (Senior Visiting Scientist, iTHEMS / Specially Appointed Professor, Tokyo Institute of Technology)
Dr. Tomoki Ozawa (Visiting Scientist, iTHEMS / Associate Professor, Advanced Institute for Materials Research (AIMR), Tohoku University)

Public Lecture "Math meets Quantum Materials" for high school students and above will be held. The lecture will introduce the latest topics in mathematics and physics, such as topology and quantum computers, in an easy-to-understand manner.

Venue: via Online

Event Official Language: Japanese

Seminar

DMWG Seminar

The Uchuu Simulations: Data Release 1 and Dark Matter Halo Concentrations

October 1 at 14:00 - 15:00, 2020

Dr. Tomoaki Ishiyama (Associate Professor, Institute of Management and Information Technologies)

We introduce the Uchuu suite of large high-resolution cosmological N-body simulations. The largest simulation, named Uchuu, consists of 2.1 trillion dark matter particles in a box of 2.0 Gpc/h. The highest resolution simulation, called Shin-Uchuu, consists of 262 billion particles in a box of 140 Mpc/h. Combining these simulations we can follow the evolution of dark matter haloes (and subhaloes) spanning from dwarf galaxies to massive galaxy cluster hosts. We present basic statistics, dark matter power spectra and halo (subhalo) mass function, to demonstrate the huge dynamic range and superb statistics of the Uchuu simulations. From the analysis of the evolution of the power spectra we conclude that our simulations are accurate enough from the Baryon Acoustic Oscillations up to very small scales. We also provide parameters of a mass-concentration model, which describes the evolution of halo concentrations, that reproduces our simulation data within 5% error for haloes with masses spanning nearly eight orders of magnitude at redshift 0<z<14. We make publicly available various N -body products, as part of Uchuu Data Release 1, on the Skies & Universes site. We also plan to release gravitational lensing maps, mock galaxy, X-ray cluster and active galactic nuclei catalogues in the near future.

Venue: via Zoom

Event Official Language: English

Seminar

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Math-Phys Joint Seminar

TQFT, integrable lattice model, and quiver gauge theories

October 2 at 16:00 - 18:00, 2020

Dr. Toshihiro Ota (Student Trainee, iTHEMS / Graduate School of Science, Osaka University School of Science)

- 1st part (math): In physics literature, “lattice models” appear quite often as mathematical models of physical systems, e.g. Ising model, vertex models, lattice gauge theory. The aim of the 1st part is to introduce ‘what is (T)QFT,’ ‘what is lattice model,’ and ‘what does integrability mean’ in the language of mathematics. In turn, they will play a crucial role in the 2nd part of my talk. I also hope that this will lead to a good exchange among us, especially between physicists and mathematicians.

- 2nd part (physics): In the 2nd part, I would like to explain where an integrable lattice model may come from, especially for people in the physics background. I will show a certain class of integrable lattice models is realized by Wilson-’t Hooft lines in 4d quiver gauge theories. I will also explain a bit how these gauge theories are constructed from brane configurations in string theory. String dualities allow us to relate the original 4d setups to 4d partially topological Chern-Simons theory, which is a partial TQFT and generates integrable lattice models.

Venue: via Zoom

Event Official Language: English

Lecture

Forefront of Modern Science: Frontiers in Mathematics, Astronomy, Physics, Biology and Computation thumbnail

Forefront of Modern Science: Frontiers in Mathematics, Astronomy, Physics, Biology and Computation

October 2 at 16:20 - 17:50, 2020

Dr. Tetsuo Hatsuda (Program Director, iTHEMS)
Dr. Yuka Kotorii (Visiting Scientist, iTHEMS / Associate Professor, Mathematics Program, Graduate School of Advanced Science and Engineering, Hiroshima University / Visiting Scientist, Mathematical Analysis Team, RIKEN Center for Advanced Intelligence Project (AIP))
Dr. Shigehiro Nagataki (Deputy Program Director, iTHEMS / Chief Scientist, RIKEN Astrophysical Big Bang Laboratory)
Dr. Makiko Nio (Senior Researcher, RIKEN Nishina Center for Accelerator-Based Science (RNC))
Dr. Ryosuke Iritani (Research Scientist, iTHEMS)
Dr. Ai Niitsu (Postdoctoral Researcher, Theoretical Molecular Science Laboratory, RIKEN)
Dr. Shigenori Otsuka (Research Scientist, iTHEMS / Research Scientist, Data Assimilation Research Team, RIKEN Center for Computational Science)
Dr. Emi Yukawa (Assistant Professor, Department of Physics, Faculty of Science Division I, Tokyo University of Science)

Venue: Changed to Zoom

Event Official Language: Japanese

External Event

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Tetsuo Hatsuda x Koji Hashimoto x Aiko Teranishi "Science for the Future"-"The Usefulness of Useless Knowledge" (University of Tokyo Press) Commemorative Publication

October 10 at 15:00 - 17:00, 2020

Dr. Tetsuo Hatsuda (Program Director, iTHEMS)
Prof. Koji Hashimoto (Professor, Department of physics, Osaka University)
Ms. Aiko Teranishi (President and CEO, indigo.inc)

Dr. Tetsuo Hatsuda, iTHEMS Program Director, published "The Usefulness of Useless Knowledge" in this July by the University of Tokyo Press. This book is a collection of essays by Abraham Flexner, the first director of the Institute for Advanced Study in Princeton, USA, and Robbert Dijkgraaf, the current director.

To celebrate the publication of this book, a talk event will be held at Bookstore B&B.

Venue: via Zoom

Event Official Language: Japanese

External Event

The Mathematical Society of Japan: Cross-discipline and cross-industry research exchange meeting 2020

October 31 at 10:00 - 17:00, 2020

「数学・数理科学専攻若手研究者のための異分野・異業種研究交流会(研究交流会)」は、 数学・数理科学専攻の博士課程学生をはじめとする若手研究者と産業界を含む異分野の方々 との「双方向の交流の場」として2014年から開催しております。若手研究者の皆様に、諸科学や産業への応用展開のような数学の思わぬ力を発見してもらう ことや、産業界を含む様々な分野で活躍できる場の存在を認識してもらうことが主たる目的 です。高等学校、大学を含む教育・研究機関の教職員や企業関係者の皆様にも、産業界における数学 ・数理科学やその知識を有する人材のニーズを把握してもらうことも目的の一つです。

Venue: via Online

Event Official Language: Japanese

Paper of the Week

Week 4 of September

2020-09-24

Title: Polynomial growth of out-of-time-order correlator in arbitrary realistic long-range interacting systems
Author: Tomotaka Kuwahara, Keiji Saito
arXiv: http://arxiv.org/abs/2009.10124v1

Title: Rainbow Nambu-Goldstone modes under a nonequilibrium steady flow
Author: Yuki Minami, Hiroyoshi Nakano, Yoshimasa Hidaka
arXiv: http://arxiv.org/abs/2009.10357v1

Title: Path integral of neutrino oscillations
Author: Kazuo Fujikawa
arXiv: http://arxiv.org/abs/2009.08082v1

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