Workshop

Recent Developments and Challenges in Topological Phases

June 3 (Mon) - 14 (Fri), 2024

Thanks to intensive research efforts, topology has been established as a fundamental concept in physics. For closed quantum systems, the classification of gapped topological phases has matured. Moreover, the importance of topology is not limited to isolated quantum systems. Recently, the topology of non-Hermitian Hamiltonians, which effectively describe systems with dissipation, has attracted much attention worldwide. This fascination is exemplified by topological phases and topological phenomena unique to non-Hermitian systems. Against this background, the primary purpose of this workshop is to bring together researchers working on topological phases and to discuss (i) open questions in topological phases of closed quantum systems and (ii) the role of topology in open quantum systems and measurements.

Venue: Yukawa Institute for Theoretical Physics, Kyoto University

Event Official Language: English

iTHEMS-YITP Workshop: Bootstrap, Localization and Holography

May 20 (Mon) - 24 (Fri), 2024

Venue: Yukawa Institute for Theoretical Physics, Kyoto University

Event Official Language: English

iTHEMS Cosmology Forum 1 - Cosmic Birefringence and Parity Violation in the Universe

May 14 (Tue) at 9:30 - 18:00, 2024

Toshiya Namikawa (Project Assistant Professor, Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU), The University of Tokyo)
Maresuke Shiraishi (Associate Professor, Suwa University of Science)
Fuminobu Takahashi (Professor, Department of Physics, Graduate School of Science, Tohoku University)

iTHEMS Cosmology Forum Workshop is a series of short workshops, each focused on an emerging topics in cosmology. The targeted audience is cosmologists, high-energy physicists and astronomers interested in learning about the subject, not just those who have already worked on the topic. The goal of the workshop is to provide working knowledge of the topic and leave dedicated time for discussions to encourage mutual interactions among participants. The first workshop is devoted to cosmic birefringence, a newly establishing cosmological probe of the nature of our universe. Cosmic birefringence is the rotation of the linear polarization plane of the cosmic microwave background (CMB) radiation and, thanks to its origin, inherently measures the degree of parity violation in the cosmic history. This one-day workshop gathers both the observational and theoretical aspects of this growing topic. The workshop will be in English. The venue is on RIKEN Wako Campus, and the exact room is yet to be determined, depending on the number of registered participants. The workshops are organised by the iTHEMS Cosmology Forum working group, which is the successor of the Dark Matter Working Group at RIKEN iTHEMS. Important dates: 30th April - Registration deadline 14th May - Workshop Day Invited Speakers: Toshiya Namikawa (Kavli IPMU) Maresuke Shiraishi (Suwa University of Science) Fuminobu Takahashi (Tohoku University) Organisers: Kohei Hayashi, Nagisa Hiroshima, Derek Inman, Amaury Micheli, Ryo Namba

Venue: #435-437, 4F, Main Research Building

Event Official Language: English

Nuclear Fusion and its Interdisciplinary Fields

May 14 (Tue) at 9:00 - 18:15, 2024

We will learn about nuclear fusion and related subjects, such as turbulence in astronomy and astrophysics, from experts and discuss possible interdisciplinary collaborations in the near future. Some researchers will visit RIKEN iTHEMS from the National Institute for Fusion Science (NIFS) and other universities and research institutes for the workshop. We will have the workshop in a hybrid style so that many researchers in Japan can hear the presentations even remotely. This workshop is supported by Moonshot Goal 10 (Program Director Yoshida Zensho (NIFS)). Program Session１ 9:00-9:35 (25+10: 25 mins for Presentation, 10 mins for Q&A)：Shinya Maeyama 9:35-10:10 (25+10): Naoki Sato 10:10-10:45 (25+10): Yohei Kawazura 10:45-11:15 Coffee Break Session２ 11:15-11:50 (25+10): Takanobu Amano 11:50-12:25 (25+10): Yosuke Matsumoto 12:25-13:00 (25+10): Akira Mizuta 13:00-14:00 Lunch Break Session３ 14:00-14:35 (25+10): Chiho Nonaka 14:35-15:10 (25+10): Takeo Hoshi 15:10-15:45 (25+10): Motoki Nakata 15:45-16:15 Coffee Break Session ４ 16:15-16:50 (25+10): Kumiko Hori 16:50-17:25 (25+10): Yutaka Ohira 17:25-18:00 (25+10): Camilia Demidem (TBC) 18:30-20:30: Dinner in the Main Research Building.

Venue: Seminar Room #359 (Main Venue) / via Zoom

Event Official Language: English

Condensed Matter Physics of QCD 2024

March 11 (Mon) - 22 (Fri), 2024

Gordon Baym (Professor Emeritus, University of Illinois, USA)
Muneto Nitta (Professor, Keio University)
Mark Alford (Professor, Washington University in St. Louis, USA)
Sanjay Reddy (Professor, University of Washington, USA)
Dam Thanh Son (Professor, The University of Chicago, USA)
Mikhail Stephanov (Professor, The University of Illinois at Chicago (UIC), USA)
Kenji Fukushima (Professor, Department of Physics, Graduate School of Science, The University of Tokyo)
Naoki Yamamoto (Associate Professor, Keio University)
Koutarou Kyutoku (Associate Professor, Graduate School of Science, Kyoto University)
Yui Hayashi (Postdoctoral researcher, Yukawa Institute for Theoretical Physics, Kyoto University)
Kentaro Nishimura (Postdoctoral researcher, Hiroshima University)
Toru Kojo (Associate professor, Tohoku University)
Masakiyo Kitazawa (Lecturer, Yukawa Institute for Theoretical Physics, Kyoto University)

QCD at finite temperature and density is one of the most challenging problems in modern physics, which plays a crucial role to understand the origin and coevolution of the universe and matter. On the one hand, the relativistic heavy-ion collision experiments in the past decades have opened a new and exciting field to explore physical properties of such a QCD matter at high-tempearture. On the other hand, recent astrophysical observations of compact stars (in particular, events involving neutron stars) is becoming another exciting tool to unveil properties of the dense QCD matter. This molecule-type workshop is aimed at bringing together theorists working on QCD at finite-temperature and density, with a particular focus on dense quark-nuclear matter relevant to neutron star physics. We will mainly cover macroscopic properties of the finite-density QCD matter such as the Lee-Yang edge singularity for a QCD critical point, the renewed Fermi liquid theory for quark-nuclear matter, nuclear superfluidity, color superconductivity, quark-hadron continuity, quantum vortex, and transport phenomena including the weak-intearction processes.

Venue: via Zoom / Yukawa Institute for Theoretical Physics, Kyoto University

Event Official Language: English

RIKEN-Nara Women's University Joint Diversity Promotion Workshop 2024

February 29 (Thu) - March 1 (Fri), 2024

The RIKEN Interdisciplinary Theoretical and Mathematical Sciences Program (iTHEMS) and the Faculty of Science at Nara Women's University are promoting a project to foster female researchers under the auspices of the RIKEN Diversity Promotion Office. As part of the program, 23 undergraduate and graduate students from Nara Women's University will visit several laboratories on the RIKEN Wako campus to ask questions about their research and hold workshops/presentations with iTHEMS researchers. Organizers: RIKEN Interdisciplinary Theoretical and Mathematical Sciences Program Faculty of Science, Nara Women's University Program: Thursday, February 29 13:30-14:00 Opening remarks by Tetsuo Hatsuda (C01, Main Research Bldg. room 246-248) 14:00-15:30 Atomic, Molecular & Optical Physics Laboratory (CPR) (C32, Laser Bldg. 2F) 15:30-17:00 Neural Circuit of Multisensory Integration RIKEN Hakubi Research Team (CBS) (C56, Brain Science Ikenohata Bldg. 3F）　 17:00-18:30 RIKEN Interdisciplinary Theoretical and Mathematical Sciences Program (iTHEMS) (C01, Main Research Bldg. 3F) 18:30-21:00 Presentations by Nara Women's University Students (C01, Main Research Bldg. 3F) Friday, March 1 9:00-10:30 Nishina Center RIBF Facility (RNC) (E01, Nishina RIBF Bldg.) 10:30-12:00 Cellular Informatics Laboratory (CPR) (S01, Biology Science Bldg.3F) 12:00-13:00 Lunch (C61, Welfare and Conference Bldg.) 13:00 Closing

Venue: via Zoom

Second Workshop on Fundamentals in Density Functional Theory (DFT2024)

February 20 (Tue) - 22 (Thu), 2024

The density functional theory (DFT) is one of the powerful methods to solve quantum many-body problems, which, in principle, gives the exact energy and density of the ground state. The accuracy of DFT is, in practice, determined by the accuracy of an energy density functional (EDF) since the exact EDF is still unknown. Currently, DFT has been used in many communities, including nuclear physics, quantum chemistry, and condensed matter physics, while the fundamental study of DFT, such as the first principle derivations of an accurate EDF and methods to calculate many observables from obtained densities and excited states. However, there has been little opportunity to have interdisciplinary communication. On December 2022, we had the first workshop on this series (DFT2022) at Yukawa Institute for Theoretical Physics, Kyoto University, and several interdisiplinary discussions and collaborationd were started. To share such progresses and extend collaborations, we organize the second workshop. In this workshop, the current status and issues of each discipline will be shared towards solving these problems by meeting together among researchers in mathematics, nuclear physics, quantum chemistry, and condensed matter physics. This workshop mainly comprises lectures/seminars on cutting-edge topics and discussion, while a half-day session composed of contributed talks is also planned. This workshop is partially supported by iTHEMS-phys Study Group. This workshop is a part of the RIKEN Symposium Series. The detailed information can be found in the workshop website.

Venue: 8F, Integrated Innovation Building (IIB) (Main Venue) / via Zoom

Event Official Language: English

“Quantum-like Modeling” in Biology, Cognitive & Social Sciences

January 26 (Fri) at 9:30 - 17:00, 2024

Venue: Okochi Hall (Main Venue) / via Zoom

Event Official Language: Japanese

Functional Renormalization Group at Niigata 2024

January 7 (Sun) - 8 (Mon), 2024

Gergely Fejos (Assistant Professor, Institute of Physics, Eötvös Loránd University, Hungary)
Kenji Fukushima (Professor, Department of Physics, Graduate School of Science, The University of Tokyo)
Kouichi Okunishi (Associate Professor, Faculty of Science, Niigata University)
Junichi Haruna (Ph.D. Student, Graduate School of Science, Kyoto University)
Xu-Guang Huang (Professor, Physics Department and Center for Particle Physics and Field Theory, Fudan University, China)
Katsumi Itoh (Professor, Faculty of Education, Niigata University)
Kiyoharu Kawana (Research Fellow, Korea Institute for Advanced Study (KIAS), Republic of Korea)
Shunsuke Yabunaka (Researcher, Japan Atomic Energy Agency (JAEA))
Takeru Yokota (Special Postdoctoral Researcher, RIKEN Interdisciplinary Theoretical and Mathematical Sciences Program (iTHEMS))

One of the most fundamental challenges in theoretical physics is to uncover the physical properties of strongly-interacting quantum many-body systems. This problem is shared in both subatomic physics and condensed matter physics; e.g., to unveil ground state structures and dynamical aspects of quantum systems. However, it has been an unresolved issue to establish non-perturbative theoretical tools, which allows a reliable analytic approach to quantum many-body problems described by field theory. The Functional Renormalization Group (FRG) is proposed as one of the theoretical methods that facilitates the non-perturbative investigation of quantum many-body systems. The FRG has found applications in various fields of physics, ranging from particle and nuclear physics to condensed matter physics, leading to several unique achievements in each fields. The aim of this two-day workshop is to provide an overview of the recent applications and progress of FRG in various fields of physics, discuss future directions, and explore potential new collaborations that bridge different fields of physics.

Venue: Kaishi Professional University Yoneyama Campus (Main Venue) / via Zoom

Event Official Language: English

Joint RIKEN/N3AS Workshop on Multi-Messenger Astrophysics

November 26 (Sun) at 9:00 - 19:00, 2023

RIKEN iTHEMS and NSF Physics Frontier Center N3AS will jointly organize a workshop on "Multi-Messenger Astrophysics" on Sunday, November 26, at the Hilton Waikoloa Village, in conjunction with the JPS/ APS DNP meeting. For the program and registration form, please visit the workshop website at the related links. The workshop is open to all and there is no registration fee. However, we ask those wishing to attend to register, to help us plan. The workshop will conclude with an early evening poster session that will combine science with an opportunity for JPS and APS participants to socialize. Organizers: Tetsuo Hatsuda（RIKEN iTHEMS) Wick Haxton (UC Berkaley, N3AS) Baha Balentekin (UW-Madison, N3AS)

Venue: Hilton Waikoloa Village, Waikoloa, Hawaii

Event Official Language: English

6th QGG Intensive Lectures: Introduction to thermalization in isolated quantum systems

November 20 (Mon) - 21 (Tue), 2023

Ryusuke Hamazaki (RIKEN Hakubi Team Leader, Nonequilibrium Quantum Statistical Mechanics RIKEN Hakubi Research Team, RIKEN Cluster for Pioneering Research (CPR))

This is the sixth event by the Quantum Gravity Gatherings (QGG) Study Group at RIKEN iTHEMS. For this event we have invited Professor Ryusuke Hamazaki from RIKEN, to deliver pedagogical lectures on the thermalization in isolated quantum systems. This topic describes how a non-equilibrium quantum state relaxes to thermal equilibrium through a unitary time evolution. This theme has applications not only in statistical physics but also in many areas of physics. In particular, in the context of quantum gravity, understanding thermalization via a unitary time evolution is anticipated to be a key to resolving the information loss problem of black holes. In addition, the notion of typicality and thermalization is important in the AdS/CFT correspondence to understand black hole physics. We expect this event to provide insights to researchers in related fields. Ryusuke Hamazaki is a leading expert in this subject. It is our enormous pleasure to have the opportunity to learn from him the idea of thermalization and its applications related to realistic systems. This intensive lecture series is designed to be an interactive event. The intensive talk will be given in a face-to-face blackboard style (in English, no online streaming) to encourage informal and lively Q&A discussions. The program will also include short talk sessions, where participants can present a 5-minute talk on a topic of their choice, which could be about their own research, reviews of specific works, or future study interests.

Venue: #435-437, Main Research Building

Event Official Language: English

iTHEMS Graph-theory workshop: from basics to applications

November 13 (Mon) - 14 (Tue), 2023

Momoko Hayamizu (Assistant Professor, Faculty of Science and Engineering, School of Fundamental Science and Engineering, Waseda University / PRESTO Researcher, Japan Science and Technology Agency (JST))
Seiya Negami (Professor Emeritus, Yokohama National University)
Takashi Okada (Program-Specific Associate Professor, Institute for Life And Medical Sciences, Kyoto University)
Tasuku Soma (Associate Professor, Department of Statistical Inference and Mathematics, The Institute of Statistical Mathematics / Associate Professor, Statistical Science Program, The Graduate University for Advanced Studies (SOKENDAI))
Shun'ichi Azuma (Professor, Garduate School of Informatics, Kyoto University)

We will hold a two-day workshop on graph theory, which covers a variety of topics including basic concepts and theorems in graph-theory; graph-embedding; phylogenetic tree construction; chemical reaction networks; and cactus network theory. The details are found in the website linked below.

Venue: #435-437, Main Research Building

Event Official Language: English

International Workshop on Blockchain Technology: Blockchain Kaigi 2023 (BCK23)

October 28 (Sat) - 29 (Sun), 2023

The International workshop Blockchain Kaigi (Kaigi: Meeting, Conference) aims to bring together researchers and practitioners from various communities of science and technology working on areas related to FinTech, crypto-asset, and blockchain. On February 17th – 18th of 2021 the international workshop “Blockchain in Kyoto 2021 (BCK21)” was held at Kyoto University, and the following year on August 4th – 5th the international workshop “BCK22: Blockchain Kaigi 2022” was held at Tohoku University, both gathered many participants from all over the world and ended successfully. As the third step, the international workshop “BCK23: Blockchain Kaigi 2023” will be held on October 28th -29th, 2023 at RIKEN’s Kobe Campus (Kobe City). Topics for this international conference include, but are not limited to the following. Crypto assets, cryptocurrencies Blockchain technology, cryptography/mathematics B2B and B2C solutions Anomaly detection, cyber security Digital Asset Market, Central Bank Digital Currency CBDC smart contract Application to energy and environmental problems Application to financial inclusion, remittance and digital identity Innovation policy Legal and regulatory issues Network Science, Graph Theory, Mathematics of Hypergraphs

Venue: 8F, SUURI-COOL (Kobe)

Event Official Language: English

Introduction to F-Theory

October 18 (Wed) - 20 (Fri), 2023

Shun'ya Mizoguchi (Associate Professor, High Energy Accelerator Research Organization (KEK))

This is the fifth event hosted by the Quantum Gravity Gatherings (QGG) Study Group at RIKEN iTHEMS. For this event, we have invited Professor Shun'ya Mizoguchi from KEK, Tsukuba, to deliver pedagogical lectures on the F-theory and its relation to particle physics. We aim for this event to provide insights to researchers in related fields. Originally, heterotic string theory was a promising candidate for describing our world, as it naturally incorporated Grand Unified Theory (GUT) based on an exceptional gauge group. However, heterotic theory encounters challenges in moduli fixing. On the other hand, type II theory has an advantage in moduli fixing, but realizing GUT proves to be challenging. The F-theory describes the strongly coupled type IIB string theory, fully utilizing string dualities. This theory appears to realize both the moduli fixing and GUT. Consequently, F-theory plays a central role in string phenomenology. Shun'ya is a leading expert in these areas. We are fortunate to have the opportunity to learn numerous insights into string theory as well as particle physics. This intensive lecture series is designed to be an interactive event. To facilitate this, the number of participants will be limited to approximately 30. The intensive talk will be given in a face-to-face blackboard style (in English, no online streaming) to encourage informal and lively Q&A discussions. The program will also include short talk sessions, where participants can present a 5-minute talk on a topic of their choice, including their research, reviews of specific works, or future study interests.

Venue: #435-437, 4F, Main Research Building

Event Official Language: English

The 4th "Medicine and Mathematics" Workshop

September 29 (Fri) - 30 (Sat), 2023

We will have the 4rd workshop on "Medicine and Math" in Sendai (hybrid style) on Sep.29-30, 2023. Please join if you are interested in this interdisciplinary subject. Most of the talks are in Japanese except for session 4. For more information and registration, please visit the related links. For more information and registration, please visit the related links. Co-organized by: Center for Integrative Medicine and Physics, Kyoto University Institute for Advanced Study (KUIAS) Center for Science Adventure and Collaborative Research Advancement (SACRA), Kyoto University Tohoku Forum of Creativity, Tohoku University RIKEN Interdisciplinary Theoretical and Mathematical Sciences Program (iTHEMS)

Venue: TOKYO ELECTRON House of Creativity, Katahira Campus, Tohoku University / via Zoom

The 19th High Performance Computing Physics (HPC-Phys) Workshop

August 31 (Thu) at 13:30 - 17:30, 2023

Computational science is indispensable research method in various fields in physics. On the other hand, there is technical challenge in massive numerical simulations, such as optimization for each computational system and proper choice of computational method, and it is desirable to promote interdisciplinary collaborations between different fields. This series of workshops is organized to enhance such interdisciplinary activities among wide area of computational physics. The 19th workshop will be held with the following program: Program 13:30-13:35 Introduction 13:35-14:25 Tomonori Shirakawa : "Simulation of quantum computation using tensor network method" 14:25-15:15 Misa Ogata : "New computational method using Lagrangian construction for equilibrium shape of 2-dimensional stars" 15:15-15:35 Break 15:35-16:25 Rico Pohle : "Semi-classical Monte Carlo and molecular dynamics simulations of spin coherent states" 16:25-17:15 Ken-Ichi Ishikawa : "Algorithms for Lattice Quantum Chromodynamics" 17:15-17:30 Discussions (17:30- Informal social gathering)

Venue: Welfare and Conference Bldg. 2F Meeting Room, RIKEN Wako Campus

Event Official Language: Japanese

Exploring 2D Quantum Spacetime Based on Causal Dynamical Triangulations

August 21 (Mon) - 23 (Wed), 2023

Yuki Sato (Associate Professor, National Institute of Technology, Tokuyama College)

This is the fourth event by the Quantum Gravity Gatherings (QGG) Study Group at RIKEN iTHEMS. For this event we have invited Prof. Yuki Sato, National Institute of Technology, Tokuyama College, to give pedagogical lectures on the causal dynamical triangulations approach to quantum gravity. We wish this event to provide insights to researchers in related fields. The causal dynamical triangulations formalism appears to be one of the most promising constructive approaches to quantum gravity: possessing deep links with the asymptotic safety programme and Hořava-Lifshitz gravity, causal dynamical triangulations appears to avoid many of the well-known pathologies characteristic of its Euclidean analogue. As an example the emergence of spacetime geometry remains possible in various spacetime dimensions. While many of the results in higher dimensions are understood only at the numerical level, the analytical study of the approach in two spacetime dimensions is relatively well developed; Yuki Sato is a leading expert on these latter developments and we are very lucky he has agreed to present the understanding of 2D causal spacetime coming from this approach in a manner consistent with the Quantum Gravity Gatherings philosophy. This intensive lecture series is intended to be a lively and participatory event, not just a listening experience. For this reason, the number of participants will be limited to about 30 with priority given to graduate students and young post-docs; the intensive talk will be given in a face-to-face blackboard style (in English, no online streaming) to allow for informal and lively Q&A discussions. The program will also include short talk sessions, where interested participants can give a 5 min talk on a topic of their choice (their research, reviews on some works, what they want to study in the future, etc.). Registration is available via the dedicated website.

Venue: #435-437, 4F, Main Research Building

Event Official Language: English

6th Workshop on Virus Dynamics

July 4 (Tue) - 6 (Thu), 2023

Catherine Beauchemin (Deputy Program Director, RIKEN Interdisciplinary Theoretical and Mathematical Sciences Program (iTHEMS))
Shingo Iwami (Professor, Graduate School of Science, Nagoya University)

The Workshop on Virus Dynamics is an international meeting held every 2 years. It brings virologists, immunologists, and microbiologists together with mathematical and computational modellers, bioinformaticians, bioengineers, virophysicists, and systems biologists to discuss current approaches and challenges in modelling and analyzing different aspects of virus and immune system dynamics, and associated vaccines and therapeutics. This 6th version of the workshop builds on the success of previous ones held in Frankfurt (2013), Toronto (2015), Heidelberg (2017), Paris (2019) and virtually (2021). It is supported by the Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS) program at RIKEN, by Nagoya University, and by the Japan Science and Technology Agency. Up-to-date information and registration is available via the website. The workshop is for in-person participation only (no virtual or hybrid option).

Venue: Noyori Conference Hall, Higashiyama Campus, Nagoya University

Event Official Language: English

iTHEMS Science Outreach Workshop 2023

June 16 (Fri) - 18 (Sun), 2023

This year's meeting on "Outreach of RIKEN iTHEMS 2023@Sendai&Zoom" will be held from FRI June 16 to SUN June 18, as a face-to-face meeting at TOKYO ELECTRON House of Creativity of Tohoku Forum for Creativity in cooperation with iTHEMS SUURI-COOL (Sendai) using ZOOM for the necessary part as well.

Venue: TOKYO ELECTRON House of Creativity, Katahira Campus, Tohoku University / via Zoom

Event Official Language: Japanese

Exploring GPT’s Influence on Natural Science and Mathematics

May 17 (Wed) at 10:00 - 15:00, 2023

We are organizing a workshop to explore the application of ChatGPT in natural sciences, with a focus on theoretical physics and mathematics. Advances in GPT-4 and plugin technology are expected to bring about transformative changes in the way research is conducted. We will investigate the potential for another shift in research methodology following the advent of computers. Expert-led lectures on large language models (LLMs/ChatGPT) will also be conducted. We aim to deepen the discussion on the effective utilization of LLMs as tools to support the research of physicists and mathematicians. This workshop will be held in a hybrid format, combining online streaming with in-person presentations, to accommodate a larger number of participants. In addition to the lectures, short talks and discussions will be held entirely offline. The target audience is mainly students and researchers in the natural sciences, but please note that there will be a limit to the number of in-person attendees. The aim of this event is to provide a forum for researchers to engage in earnest discussions. Those who do not align with the objectives of this workshop are kindly asked to refrain from participating. We look forward to this opportunity to consider, together with all of you, new research methods and perspectives in the fields of theoretical physics and mathematics in the natural sciences, utilizing ChatGPT. (The above text was created by modifying the text generated by Chat-GPT and GPT-4.) All talks will be delivered in Japanese.

Venue: #435-437, 4F, Main Research Building (Main Venue) / via Zoom

Event Official Language: Japanese