News
63 news in 2025
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2025-05-14
Person of the Week
Self-introduction: Shuntaro Aoki
Hello, My name is Shuntaro Aoki, and I am a researcher at RIKEN iTHEMS. My primary areas of expertise are particle physics and cosmology, with a special focus on the early universe. I obtained my PhD from Waseda University in 2018 and worked as a lecturer at the same institution until March 2021. In April 2021, I joined Chung-Ang University in Korea, where I worked until August 2022. Subsequently, I continued my research at the Institute for Basic Science (Korea) until November 2024, before joining RIKEN iTHEMS in December 2024. My current research focuses on the cosmological collider program, which aims to uncover new physics beyond the Standard Model through the study of non-Gaussianity in primordial perturbations. These perturbations, believed to have been generated in the early universe at extremely high energies, provide valuable insights into heavy particles that are inaccessible in terrestrial experiments. Specifically, I have been working on the theoretical aspects of the cosmological collider, such as deriving analytic expressions for correlation functions and exploring particle physics models that predict large "signals" of interest. This research lies at the intersection of cosmology and particle physics, offering exciting implications for both fields. My long-term goal is to contribute to uncovering high-energy physics through cosmological observations. Ultimately, I aim to deepen our understanding of the universe's fundamental nature and its origins, while fostering new methodologies and collaborative efforts to advance the field. Beyond research, I enjoy football, fishing, and walking—activities that help me maintain a balanced and creative approach to problem-solving.
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2025-05-14
Person of the Week
Self-introduction: Iao-Fai Io
Hello everyone, my name is Iao-Fai Io, you can call me Jacky (my nickname). I am a Ph.D. student at National Taiwan University (NTU) and also an IPA student at RIKEN iTHEMS. Although I study in Taiwan, I am originally from Macau, so I know how to speak cantonese and mandarin My research direction is condensed matter physics, specifically focusing on non-Hermitian systems, particularly one-dimensional lattice models (e.g., the SSH model and its extended versions). Currently, I am studying conformal symmetry in 1+1D non-Hermitian systems, including both lattice models and field theory, to understand the differences between Hermitian and non-Hermitian cases and to explore new physics in non-Hermitian systems. I am also interested in other topics in condensed matter theory, including topological insulators and superconductors.
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2025-05-13
Person of the Week
Self-introduction: Daichi Takeda
My name is Daichi Takeda. I was born in Himeji (Hyōgo Prefecture), and have also lived in Fujisawa (Kanagawa) and Kyoto (Kyoto). I spent nine years at Kyoto University — from my undergraduate studies through my doctoral program — and received a Ph.D. in Science in March 2024. My field is theoretical high energy physics, with a focus on exploring the microscopic theory of gravity. Recently, I have been investigating the properties of black holes and methods for conducting virtual gravity experiments in a laboratory setting, with the help of the holographic principle.
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2025-05-13
Person of the WeekSelf-introduction: Dorothy Ellis
Hello! I'm Dorothy Ellis. I received my PhD in biostatistics from the University of Florida in August 2023 and joined the Laboratory for Integrative Genomics at RIKEN IMS in October 2023 as a postdoctoral researcher. I was concurrently appointed to iTHEMS in May 2025. My primary research interest is in developing machine learning and data analysis methods (especially unsupervised analysis methods) for multi-omics data.
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2025-05-09
Seminar Report
iTHEMS Theoretical Physics Seminar by Nagare Katayama on May 9, 2025
On May 9, Mr. Nagare Katayama gave a seminar hosted by RIKEN iTHEMS. His talk focused on 2d Cardy-Rabinovici model with the modified Villain lattice formulation. One of the most famous scenarios of the quark confinement problem is the dual superconductor picture. In this picture, the quark confinement is induced by monopole condensation. Still, in the theory with a θ term, we expect that monopole and dyon condensation is induced, as suggested by Cardy and Rabinovici through their intuitive arguments. He discussed that the Witten effect of the theory of two-dimensional compact bosons with the θ term is examined using a modified Villain-type lattice theory that can treat the θ term and dion rigorously. In addition, he constructed the 2d Cardy-Rabinovici model and analyzed the phase diagram through the scaling dimension argument and the anomaly matching constraint. Reported by Okuto Morikawa
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2025-05-08
Paper of the WeekWeek 2, May 2025
Title: ASURA-FDPS-ML: Star-by-star Galaxy Simulations Accelerated by Surrogate Modeling for Supernova Feedback Author: Keiya Hirashima, Kana Moriwaki, Michiko S. Fujii, Yutaka Hirai, Takayuki R. Saitoh, Junnichiro Makino, Ulrich P. Steinwandel, Shirley Ho arXiv: http://arxiv.org/abs/2410.23346v2 Title: Pole-Expansion of Two-Hadron Imaginary-Time Correlation Function -a new method of analysis for unstable states in lattice QCD- Author: Wren Yamada, Osamu Morimatsu, Toru Sato, Koichi Yazaki arXiv: http://arxiv.org/abs/2505.02878v1 Title: Smooth concordance of cables of the figure-eight knot Author: Sungkyung Kang, JungHwan Park, Masaki Taniguchi arXiv: http://arxiv.org/abs/2505.03720v1 Title: Unified exact WKB framework for resonance -- Zel'dovich and complex-scaling regularizations Author: Okuto Morikawa, Shoya Ogawa arXiv: http://arxiv.org/abs/2505.02301v1 Title: Symmetry-adapted sample-based quantum diagonalization: Application to lattice model Author: Kosuke Nogaki, Steffen Backes, Tomonori Shirakawa, Seiji Yunoki, Ryotaro Arita arXiv: http://arxiv.org/abs/2505.00914v1 Title: Shear and bulk viscosity for a pure glue theory using an effective matrix model Author: Manas Debnath, Ritesh Ghosh, Najmul Haque, Yoshimasa Hidaka, Robert D. Pisarski arXiv: http://arxiv.org/abs/2504.20138v1
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2025-05-01
Seminar Report
From Quarks to Neutron Stars: Insights from kHz gravitational waves on April 23, 2025
This conference focused on the role of high-frequency gravitational waves in advancing multi-messenger astrophysics. Key topics included binary neutron star mergers, such as GW170817, and future prospects for observing core-collapse supernovae using electromagnetic signals, neutrinos, and gravitational waves. Discussions highlighted the importance of kilohertz-band gravitational waves in probing the dense interiors of neutron stars, where exotic matter may exist. The seminar also introduced new detector concepts like NEMO in Australia and planned KAGRA upgrades aimed at enhancing high-frequency sensitivity. The event featured expert talks and posters, promoting collaboration and new research directions in nuclear and neutron star physics. Reported by Shuntaro Aoki
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2025-05-01
Paper of the WeekWeek 1, May 2025
Title: High energy extragalactic multimessenger backgrounds from starburst and dead galaxies Author: Ellis R. Owen, Yoshiyuki Inoue, Tatsuki Fujiwara, Albert K. H. Kong arXiv: http://arxiv.org/abs/2504.18721v1 Title: Lindblad dynamics in holography Author: Takanori Ishii, Daichi Takeda arXiv: http://arxiv.org/abs/2504.17320v1 Title: Explosive production of Higgs particles and implications for heavy dark matter Author: Seishi Enomoto, Nagisa Hiroshima, Kohta Murase, Masato Yamanaka arXiv: http://arxiv.org/abs/2504.17127v1 Title: FRG analysis for relativistic BEC in arbitrary spatial dimensions Author: Fumio Terazaki, Kazuya Mameda arXiv: http://arxiv.org/abs/2504.17668v1
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2025-04-24
Paper of the WeekWeek 4, April 2025
Title: Cosmic ray neutrons in magnetized astrophysical structures Author: Ellis R. Owen, Yoshiyuki Inoue, Tatsuki Fujiwara, Qin Han, Kinwah Wu arXiv: http://arxiv.org/abs/2504.15802v1 Title: A magnetar powers the luminous supernova 2023pel, associated with a long gamma-ray burst Author: L. M. Roman Aguilar, M. M. Saez, K. Ertini, M. C. Bersten arXiv: http://arxiv.org/abs/2504.11414v1 Title: Performance guarantees of light-cone variational quantum algorithms for the maximum cut problem Author: Xiaoyang Wang, Yuexin Su, Tongyang Li arXiv: http://arxiv.org/abs/2504.12896v1 Title: Computing $n$-time correlation functions without ancilla qubits Author: Xiaoyang Wang, Long Xiong, Xiaoxia Cai, Xiao Yuan arXiv: http://arxiv.org/abs/2504.12975v1
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2025-04-23
Hot Topic
iTHEMS x academist online event was held on April 19, 2025
iTHEMS held an online lecture event for the general public with the help of Academist Inc., on April 19, 2025. This year’s speakers were Yuuka Kanakubo, Kan Kitamura, Leo Speidel, and Yuki Yokokura, who delivered clear and easy-to-understand lectures that even middle school students could comprehend. Each speaker also served as a commentator for other lectures and facilitated Q&A sessions based on audience questions. During the lunch break, as part of the lunch program, Director Iso, a physicist, and Prof. Fumiharu Kato, a mathematician, engaged in a discussion about the future possibilities of mathematics, moderated by Ms. Shinozaki. The event was organized and hosted by Ms. Michibayashi and Mr. Katada from Academist, who helped make the event a success. The event was attended by 414 people, and at one point there were over 250 in the audience.
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2025-04-17
Paper of the WeekWeek 3, April 2025
Title: Cohomology ring of unitary $N=(2,2)$ full vertex algebra and mirror symmetry Author: Yuto Moriwaki arXiv: http://arxiv.org/abs/2504.09919v1
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2025-04-17
Award
Masazumi Honda received "Commendation for Science and Technology: the Young Scientists' Award"
Our colleague Masazumi Honda received "Commendation for Science and Technology: the Young Scientists' Award" in recognition of his outstanding research achievements in the theoretical studies of strong-coupling dynamics in quantum field theories. Congratulations to Masazumi !
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2025-04-14
Research News
RIKEN Research: When it comes to modeling, even unmeasurable data tells us something
Mathematical models for predicting how cancer tumors in mice grow over time can give distorted results if unmeasurable data is ignored, a team that includes two RIKEN researchers has shown1. This finding has important implications when applying mathematical models to medicine. A self-confessed data geek, Catherine Beauchemin of the RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS) specializes in applying the power of math to everything from viruses to supernovae. “I love trying to figure out what data are telling us,” she says. Seeking new insights into cancer mechanisms, Beauchemin’s team used mathematical models to analyze previously published data of tumor-size measurements over time for ten mice. To read more, please visit the related link.
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2025-04-14
Research News
RIKEN Research: Refined test could improve Parkinson’s disease diagnosis
A team that includes a RIKEN researcher has refined a lab test for measuring protein aggregate levels in samples from patients with certain neurodegenerative diseases1. This has the potential to improve diagnosis and drug development for these diseases. Synucleinopathies are neurodegenerative diseases such as Parkinson’s disease and dementia with Lewy bodies. They are associated with the accumulation of aggregates of misfolded alpha-synuclein proteins in the brain and spinal cord. “When a misfolded alpha-synuclein protein in a neuron encounters one of its properly folded counterparts, it causes it to become misfolded,” says Catherine Beauchemin of the RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences. “The two misfolded alpha-synuclein proteins stick together and cause other normal alpha-synuclein to misfold and aggregate.” To read more, please visit the related link.
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2025-04-14
Press ReleaseDemonstration of Quantum Information Delocalization in a Periodically Driven System
A collaborative research team, including Visiting Scientists Yuta Kikuchi and Tomoya Hayata, has demonstrated that a scrambled state—in which quantum information becomes delocalized—can be prepared using a quantum circuit that simulates a periodically driven system. This was achieved with an ion-trap quantum computer. Scrambled states possess characteristics that are expected to be beneficial for quantum information recovery and many-body quantum system computations. This achievement represents an early-stage application of quantum computing in an academic research domain where physical phenomena and quantum information intersect, and is anticipated to contribute to the promotion of quantum computing utilization in Japan. In this study, the research team confirmed that a scrambled state—previously typically discussed using random quantum circuits—can also be prepared using periodically driven quantum circuits. This was validated through a combination of practical implementation on a high-fidelity quantum computer, appropriate error mitigation techniques, and theoretical analysis. For further details, please refer to the press release available via the related link.
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2025-04-14
Research News
RIKEN NEWS: Exploring Critical Magnetic Transport Phenomena with a Quantum Simulator
An interview with Yuta Sekino (Postdoctoral Researcher, iTHEMS) has been featured in Research Highlights, part of the "Close-up RIKEN 2025" series on RIKEN’s research introduction page. It has also been published in SPRING 2025 issue of RIKEN’s public relations magazine, RIKEN NEWS. Postdoctoral Researcher Yuta Sekino is theoretically investigating the behavior of "many-particle systems," which are collections of particles. He devised a new model that captures the flow of magnetism by confining individual atoms in an ultrafine lattice (optical lattice) created with lasers. Through theoretical calculations based on this model, he discovered a mysterious magnetic transport phenomenon. For more details, please see the related link.
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2025-04-10
Paper of the WeekWeek 2, April 2025
Title: Irrationality of the reciprocal sum of doubly exponential sequences Author: Junnosuke Koizumi arXiv: http://arxiv.org/abs/2504.05933v1 Title: Re-evaluation of the deuteron-deuteron thermonuclear reaction rates in metallic deuterium plasma Author: Faisal Etminan arXiv: http://arxiv.org/abs/2504.05003v1 Title: Thermonuclear superburst of MAXI J1752$-$457 observed with NinjaSat and MAXI Author: Amira Aoyama, Teruaki Enoto, Takuya Takahashi, Sota Watanabe, Tomoshi Takeda, Wataru Iwakiri, Kaede Yamasaki, Satoko Iwata, Naoyuki Ota, Arata Jujo, Toru Tamagawa, Tatehiro Mihara, Chin-Ping Hu, Akira Dohi, Nobuya Nishimura, Motoko Serino, Motoki Nakajima, Takao Kitaguchi, Yo Kato, Nobuyuki Kawai arXiv: http://arxiv.org/abs/2504.04352v1 Title: Finite-Temperature Perturbation Theory of Rotating Scalar Fields Author: Ryo Kuboniwa, Kazuya Mameda arXiv: http://arxiv.org/abs/2504.04712v1 Title: A satellite formula for real Seiberg-Witten Floer homotopy types Author: Jin Miyazawa, JungHwan Park, Masaki Taniguchi arXiv: http://arxiv.org/abs/2504.03270v1
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2025-04-09
Hot Topic
Greeting from the Director, Satoshi Iso
This April, iTHEMS entered a new phase with a renewed and expanded structure. While we continue to grow and evolve, the spirit of iTHEMS remains unchanged.
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2025-04-08
Research NewsRIKEN NEWS: Unraveling the Evolutionary Mechanisms of Cooperative Behavior Using Fugaku
An interview article with Yohsuke Murase (Senior Research Scientist) has been featured in Research Highlights, part of the "Close-up RIKEN 2025" series on RIKEN’s research introduction page. It has also been published in SPRING 2025 issue of RIKEN’s public relations magazine, RIKEN NEWS. We humans, often described as social animals, engage in "cooperative behavior"—working together and helping one another. Focusing on the key role played by "reputation," Dr. Yohsuke Murase and an international research team analyzed the dynamics of this information using the supercomputer Fugaku. Their findings revealed the evolutionary path of humanity, shaped by cooperative behavior. For more details, please refer to the related links.
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2025-04-08
Hot Topic
iTHEMS Starter Meeting for FY 2025 on April 4, 2025
On Friday, April 4, 2025, the annual iTHEMS Starter Meeting was held at 12:30 PM in Suzuki Umetaro Hall. Unlike the regular Coffee Meetings that take place every Friday at the same time, the Starter Meeting marks the beginning of the academic year and serves as a special occasion to introduce new members, allow existing members to reintroduce themselves, and share the outlook for the year ahead. This year’s meeting was held on a larger scale than usual to commemorate a major organizational milestone—the transformation of iTHEMS from a program into the newly established RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences. The meeting opened with a commemorative talk by Tetsuo Hatsuda, former Program Director, who reflected on the history of interdisciplinary mathematical science research at RIKEN, beginning with the iTHES program and leading up to the evolution of iTHEMS. He also expressed heartfelt appreciation for the contributions of former Deputy Program Directors Takashi Tsuboi and Takemasa Miyoshi. Following his talk, the new Center Director, Satoshi Iso, provided an overview of the structure and vision for the newly reorganized iTHEMS, including the establishment of new research units and teams designed to further expand and deepen the center’s interdisciplinary mission. Flower bouquets were then presented to Hatsuda-san and Tsuboi-san as a gesture of gratitude, while Miyoshi-san, who was absent, was also acknowledged for his contributions. After a brief intermission, Tsukasa Tada, Deputy Director, introduced the newly adopted iTHEMS Code of Conduct. He emphasized its core principles—mutual respect, scientific integrity, inclusivity, and responsibility—and explained how the Code reflects the ethical foundation that each member is encouraged to uphold and shape as the community evolves. This was followed by a series of one-minute self-introductions by all members, each using a single slide, continuing the tradition of fostering familiarity and collaboration across disciplines. The meeting concluded slightly before 5:00 PM, after which participants returned to the Main Research Building to attend a reception in the open space on the third floor. The reception provided an opportunity for further discussion and networking among iTHEMS members and affiliated researchers, marking a warm and promising start to the new academic year under the expanded vision of the iTHEMS Center.
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2025-04-08
Hot Topic
Takashi Tsuboi Appointed Honorary Research Fellow at RIKEN
The former Deputy Program Director of iTHEMS, Takashi Tsuboi, has been appointed "Honorary Research Fellow" at RIKEN by President Makoto Gonokami, effective April 1, 2025.This honor recognizes Takashi’s many years of distinguished service as Deputy Program Director of iTHEMS (FY2017–FY2024), as well as his outstanding achievements and dedicated contributions. He will continue to support iTHEMS as a Senior Visiting Scientist. Congratulations, Takashi!
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2025-04-07
Award
Yan Lyu received FY2024 RIKEN Excellent Achievement Award (RIKEN BAIHO Award 理研梅峰賞)
Our colleague Yan Lyu received the FY2024 RIKEN Excellent Achievement Award (RIKEN BAIHO Award) on March 28, 2025, in recognition of his outstanding work on “Elucidation of Genuine Tetraquarks Based on Lattice Quantum Chromodynamics.” The photo was taken on April 4, 2025, on the way to Suzuki Umetaro Hall at the Wako campus. Congratulations, Yan!
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2025-04-07
Award
Kyosuke Adachi received FY2024 RIKEN Research and Technology Incentive Award (RIKEN OHBU Award 理研桜舞賞)
Our colleague Kyosuke Adachi received the FY2024 RIKEN Research and Technology Incentive Award (RIKEN OHBU Award) on March 28, 2025, in recognition of his outstanding work on “Unveiling the Rules of Amino Acid Sequences Governing Protein Condensation.” The photo was taken on April 4, 2025, on the way to Suzuki Umetaro Hall at the Wako campus. Congratulations, Kyosuke!
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2025-04-03
Person of the Week
Self-introduction: Erik Loetstedt
I have a PhD in theoretical physics from Heidelberg University and have worked at the Max Planck Institute for Nuclear Physics, Missouri University of Science and Technology and The University of Tokyo before coming to RIKEN. I am interested in time-dependent problems in quantum mechanics, in particular strong field-molecule interaction. I am also interested in the simulation of quantum dynamics of molecules by quantum computers.
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2025-04-03
Paper of the WeekWeek 1, April 2025
Title: Higgs-Modular Inflation Author: Shuntaro Aoki, Hajime Otsuka, Ryota Yanagita arXiv: http://arxiv.org/abs/2504.01622v1 Title: The untangling number of 3-periodic tangles Author: Toky Andriamanalina, Sonia Mahmoudi, Myfanwy E. Evans arXiv: http://arxiv.org/abs/2504.01747v1 Title: Universality of Rényi Entropy in Conformal Field Theory Author: Yuya Kusuki, Hirosi Ooguri, Sridip Pal arXiv: http://arxiv.org/abs/2503.24353v1 Title: Unstable chords and destructive resonant excitation of black hole quasinormal modes Author: Naritaka Oshita, Emanuele Berti, Vitor Cardoso arXiv: http://arxiv.org/abs/2503.21276v1 Title: Non-perturbative formulation of resonances in quantum mechanics based on exact WKB method Author: Okuto Morikawa, Shoya Ogawa arXiv: http://arxiv.org/abs/2503.18741v2 Title: A Promising Method for Strongly Correlated Electrons in Two Dimensions: Gutzwiller-Guided Density Matrix Renormalization Group Author: Hui-Ke Jin, Rong-Yang Sun, Hong-Hao Tu, Yi Zhou arXiv: http://arxiv.org/abs/2503.18374v1 Title: Effective field theory for weakly bound two-neutron halo nuclei: corrections from neutron-neutron effective range Author: Davi B. Costa, Masaru Hongo, Dam Thanh Son arXiv: http://arxiv.org/abs/2503.18519v1 Title: Path to an exact WKB analysis of black hole quasinormal modes Author: Taiga Miyachi, Ryo Namba, Hidetoshi Omiya, Naritaka Oshita arXiv: http://arxiv.org/abs/2503.17245v1 Title: Observation of Two Cascading Screening Processes in an Iron-based Superconductor Author: Ming-Hua Chang, Steffen Backes, Donghui Lu, Nicolas Gauthier, Makoto Hashimoto, Guan-Yu Chen, Hai-Hu Wen, Sung-Kwan Mo, Zhi-Xun Shen, Roser Valenti, Heike Pfau arXiv: http://arxiv.org/abs/2503.06314v1 Title: Monte Carlo study on Heisenberg model with local dipolar interaction Author: Etsuko Itou, Akira Matsumoto, Yu Nakayama, Toshiki Onagi arXiv: http://arxiv.org/abs/2503.15874v2
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2025-04-01
Hot Topic
Farewell message from Daiki Kumakura
Our colleague, Daiki Kumakura, joins R&D Division at Daiichi Sankyo Co. as Translational Scientist after receiving PhD last week from Hokkaido University. We wish him the best of luck in this new endeavor. Here is a message from Daiki: I joined iTHEMS as a Junior Research Associate (JRA) in April 2022, and since then I have been fortunate to experience a wealth of opportunities and engaging discussions that go far beyond what I encountered at university. When I started as a JRA, I set myself the dual goals of advancing both research and education. In research, I pursued mathematical and computational analyses with a focus on microbial themes. In education, I established a Young Researchers in Mathematical Biology group for students and organized a summer school. Additionally, I participated in public outreach by designing a “one poster per family” project, and through appearances on FM radio and our university’s YouTube channel, I helped spread the excitement of mathematical science and the unique identity of iTHEMS to students throughout Japan. I am deeply grateful to the many individuals at iTHEMS whose support made all of these endeavors possible. Thank you from the bottom of my heart. Starting in April 2025, I will be embarking on a new chapter as a Translational Scientist at Daiichi Sankyo Co., Ltd. In this role, I will analyze and interpret clinical trial data across various disease areas, including cancer, with the aim of enabling faster and more appropriate drug prescriptions for patients. I look forward to applying the invaluable experiences I gained at iTHEMS to establish a strong position for mathematical science in industrial applications. My career has flourished thanks to iTHEMS, and I sincerely wish for the continued growth and success of the iTHEMS community. I hope to maintain close ties with all of you in the future. Thank you very much for everything.
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2025-03-28
Book
Exploring Nuclear and Hadron Physics
Author: Tetsuo Hatsuda et al. Language: Japanese Release date: February, 2025
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2025-03-27
Book
The Story of the "Discovery" of Numbers
Author: Hiroyasu Miyazaki Language: Japanese Release date: March 25, 2025
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2025-03-26
Seminar Report
A Century of Quantum Mechanics by Gordon Baym on March 24, 2025
On March 24, Professor Gordon Baym gave a joint seminar hosted by the Department of Physics at the University of Tokyo and RIKEN iTHEMS, held at the Hongo campus of the University of Tokyo. His talk focused on the history of quantum mechanics, tracing its development and highlighting the contributions of key figures such as Max Planck, Albert Einstein, Niels Bohr, and Werner Heisenberg. He also discussed the profound impact of quantum mechanics on modern technology, particularly its role in the invention of the transistor and the cellphone. In addition, Professor Baym offered inspiring insights into the importance of phase information and the concept of the quantized photon. The seminar drew more than 100 attendees, including participants via Zoom, and concluded with a lively and engaging Q&A session. Reported by Tetsuo Hatsuda
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2025-03-24
Hot Topic
Farewell message from Akihisa Yamamoto
Our colleague, Akihosa Yamamoto, will be joining Department of Mechanical Systems Engineering, Faculty of Systems Design at Tokyo Metropolitan University as an Associate Professor starting April 1st, 2025. We will all miss him and wish him the best of luck in this new endeavor. Here is a message from Akihisa: I joined RIKEN iTHEMS as a research scientist in April 2024. Although it has only been a year, I truly enjoyed my time here. I have encountered many exciting and diverse research topics that have significantly expanded my scientific horizons and thoroughly enjoyed attending seminars across various fields. Due to the great diversity and high quality of the presentations, it has not always been easy to grasp the key take-home messages and formulate relevant questions. Nonetheless, I have always enjoyed the opportunity to immerse myself in these stimulating discussions. I am also very grateful for the positive atmosphere of iTHEMS, fostered by talented and considerate colleagues. It has been a great pleasure to be a part of this fantastic institute, and I sincerely thank the Program Director Hatsuda-san and every member of iTHEMS including all the assistants for collectively maintaining such a supportive environment. I will be appointed as an Associate Professor in the Biomechanical Engineering Area in the Department of Mechanical Systems Engineering, Faculty of Systems Design at Tokyo Metropolitan University on April 1st, 2025. I plan to continue my exploration of the mechanistic understanding of homeostasis and the dynamics of living systems. I am sure that the scientific perspective and thought processes I have developed during my time at iTHEMS will remain with me throughout my scientific career. I sincerely wish for the continuous and even greater success of iTHEMS, and I look forward to staying in touch with iTHEMS members.
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2025-03-23
Hot Topic
Farewell message from Rongyang Sun
Our colleague, Rongyang Sun, will be joining Department of Physics and Astronomy, California State University Northridge, as a postdoctoral researcher, starting April 2025. We will all miss him and wish him the best of luck in this new endeavor. Here is a message from Rongyang: I joined iTHEMS in April 2023 as part of RIKEN Quantum, and you may not even meet me on campus as my base is at R-CCS in Kobe. Although my time in iTHEMS has been short, formally only half a year, and I participated in the events remotely most of the time, I learned so much, far more than I expected, from this active research institute, which owns the best diversity and productivity. I would like to thank all the members of iTHEMS, including the directors, researchers, and assistants. Thank you for giving me such a unique experience in my research career! While I am moving to the US, a physically very far away place, I will continue to follow the development of iTHEMS and share in its success. Starting in April 2025, iTHEMS will be upgraded to a research center. I sincerely wish all the members and the institute greater success in this new era!
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2025-03-20
Paper of the WeekWeek 4, March 2025
Title: Pair Correlation Conjecture for the zeros of the Riemann zeta-function I: simple and critical zeros Author: Daniel Alan Goldston, Junghun Lee, Jordan Schettler, Ade Irma Suriajaya arXiv: http://arxiv.org/abs/2503.15449v1 Title: Frustration-free free fermions Author: Seishiro Ono, Rintaro Masaoka, Haruki Watanabe, Hoi Chun Po arXiv: http://arxiv.org/abs/2503.14312v1 Title: Stable homotopy theory of invertible gapped quantum spin systems I: Kitaev's $Ω$-spectrum Author: Yosuke Kubota arXiv: http://arxiv.org/abs/2503.12618v1 Title: Frustration-free free fermions and beyond Author: Rintaro Masaoka, Seishiro Ono, Hoi Chun Po, Haruki Watanabe arXiv: http://arxiv.org/abs/2503.12879v1 Title: Modular-invariant random matrix theory and AdS${}_3$ wormholes Author: Jan Boruch, Gabriele Di Ubaldo, Felix M. Haehl, Eric Perlmutter, Moshe Rozali arXiv: http://arxiv.org/abs/2503.00101v1
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2025-03-18
Hot Topic
Farewell message from Steffen Backes
Our colleague, Steffen Backes, will be joining the RIKEN TRIP Research DX Team as an Expert Technician, starting April 1, 2025. We will all miss him and wish him the best of luck in this new endeavor. Here is a message from Steffen: I joined iTHEMS and RIKEN in August 2023, so only about 1.5 years ago, but this time had a lasting impression on my personal life and scientific career. It is hard to overstate how much I enjoyed being part of iTHEMS, as it has been an incredibly enjoyable and rewarding time. Being able to meet so many knowledgeable and kind people from different fields and parts of the world, and coming up with new and unconventional ideas due to different backgrounds, was truly amazing. I am very grateful for having been accepted to iTHEMS, which I think is a very special and outstanding place due to this diversity and scientific freedom, that is hard to be found elsewhere. In FY2025 (April 1st) I will change to an Expert Technician position in the RIKEN TRIP Research DX Team, Wako Campus, so I will still stay close to iTHEMS! As far as time allows, I will make sure to drop by and say hello :) Thank you everyone for this great time, and let's meet again soon!
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2025-03-13
Paper of the WeekWeek 3, March 2025
Title: Gyromagnetic Angular Momentum Interconversion in Neutron Stars Author: Hiroshi Funaki, Yuta Sekino, Hiroyuki Tajima, Shota Kisaka, Nobutoshi Yasutake, Mamoru Matsuo arXiv: http://arxiv.org/abs/2503.06068v2 Title: Quartet correlations near the surface of $ N = Z $ nuclei Author: Yixin Guo, Tomoya Naito, Hiroyuki Tajima, Haozhao Liang arXiv: http://arxiv.org/abs/2503.07051v1 Title: Landscape computations for the edge of chaos in nonlinear dynamical systems Author: Motoki Nakata, Masaaki Imaizumi arXiv: http://arxiv.org/abs/2503.06393v1 Title: A diagrammatic approach to the Rasmussen invariant via tangles and cobordisms Author: Taketo Sano arXiv: http://arxiv.org/abs/2503.05414v1 Title: Mirror-skin thickness: A possible observable sensitive to the charge symmetry breaking energy density functional Author: Tomoya Naito, Yuto Hijikata, Juzo Zenihiro, Gianluca Colò, Hiroyuki Sagawa arXiv: http://arxiv.org/abs/2503.05147v1
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2025-03-12
Hot Topic
Farewell message from Jizhou Li
Our colleague, Jizhou Li, will be joining Professor Akira Shudo's group in the Department of Physics at Tokyo Metropolitan University as a postdoctoral researcher, starting April 1, 2025. We will all miss him and wish him the best of luck in this new endeavor. Here is a message from Jizhou: As I move on to my next position at Tokyo Metropolitan University, I just wanted to say a big thank you to all of you. I’ve really enjoyed the discussions, collaborations, and all the insightful talks at iTHEMS. The biology seminars and coffee meetings, in particular, have been a fantastic learning experience for me. Luckily, since I live just 1 km from RIKEN, I’m not going too far! I still plan to drop by for the biology seminar every Thursday, so I’m looking forward to more chats and discussions with you all. Thanks again, and see you around!
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2025-03-12
Award
iTHEMS received the "RIKEN Diversity Innitiative Award 2024"
On March 7, 2025, iTHEMS was honored with the "RIKEN Diversity Promotion Award 2024." This marks the second consecutive recognition, following our receipt of the same award in 2023. The award acknowledges our collaborative efforts with Nara Women's University, including lectures and a visiting program since 2020, as a forward-thinking initiative to promote the active participation of women in science. A heartfelt thank you to everyone who contributed to making this initiative a success!
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2025-03-10
Award
Tomoya Naito received the “PCM2025 Jury Prize”
Our colleague Tomoya Naito (Special Postdoctoral Researcher, iTHEMS) has received the “PCM2025 Jury Prize’” of the "Single-particle and collective motions from nuclear many-body correlation (PCM2025)” symposium. The outstanding presentation poster is entitled “Isospin symmetry breaking energy density functional based on quantum chromodynamics”. Congratulations, Tomoya!
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2025-03-06
Research News
Review on Physics-Driven Learning for Inverse Problems Published in Nature Reviews Physics
Nature Reviews Physics recently published a review paper on ”Physics-driven learning for inverse problems in quantum chromodynamics”, from DEEP-IN working group led by Lingxiao Wang (Research Scientist, iTHEMS), including Tetsuo Hatsuda (Program Director, iTHEMS). The authors explore how combining deep learning techniques with physics-driven designs significantly improves the extraction of accurate physical properties from complex QCD phenomena. Highlighting applications such as lattice QCD calculations and studies of hadron interactions, neutron stars, and heavy-ion collisions, the review emphasizes the benefits of embedding physical priors into machine learning models and suggests broader potentials to general physics problems.
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2025-03-06
Paper of the WeekWeek 2, March 2025
Title: Collective Neutrino Oscillations in Three Flavors on Qubit and Qutrit Processors Author: Luca Spagnoli, Noah Goss, Alessandro Roggero, Ermal Rrapaj, Michael J. Cervia, Amol V. Patwardhan, Ravi K. Naik, A. Baha Balantekin, Ed Younis, David I. Santiago, Irfan Siddiqi, Sheakha Aldaihan arXiv: http://arxiv.org/abs/2503.00607v1
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2025-03-06
Hot Topic
RIKEN-Nara Women's University Joint Diversity Promotion Workshop 2025 on March 3, 2025
On March 3 and 4, a total of 19 students from various courses at Nara Women's University—including mathematics, physics, chemistry, biological sciences, and environmental sciences (comprising first-year, second-year, and third-year undergraduate students, as well as first-year master's students)—visited RIKEN. During their visit, they toured several research facilities, including the RIBF Facility at the RIKEN Nishina Center (RNC), the RIKEN Interdisciplinary Theoretical and Mathematical Sciences Program (iTHEMS), the Laboratory for Sensorimotor Integration at the RIKEN Center for Brain Science (CBS), the Photonics Control Technology Team at the RIKEN Center for Advanced Photonics (RAP), and the Molecular Bioregulation Research Team at the RIKEN Center for Sustainable Resource Science (CSRS). At each laboratory, the students had the opportunity to engage with cutting-edge research up close, observe experimental equipment, and ask researchers about their work. In the evening, they participated in a networking session with RIKEN researchers, where they explored research topics in depth through iTHEMS members' poster presentations. This interactive session also provided insights into the daily lives and career paths of researchers, offering students valuable inspiration from the research environment. This diversity promotion initiative is a collaborative project between the Faculty of Science at Nara Women's University and the RIKEN Interdisciplinary Theoretical and Mathematical Sciences Program (iTHEMS), conducted under the auspices of the RIKEN Diversity Promotion Office. It is organized alongside a series of lectures at Nara Women's University and is planned to continue in the coming years.
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2025-02-27
Paper of the WeekWeek 5, February 2025
Title: Detection of molecular clouds in the PeVatron candidate source LHAASO J0341$+$5258 by the Nobeyama 45-m radio telescope Author: Naomi Tsuji, Shunya Takekawa, Kaya Mori, Alison Mitchell, Shuo Zhang, Priyadarshini Bangale, Stephen DiKerby, Tülün Ergin, Jooyun Woo, Samar Safi-Harb, Shinta Kausya arXiv: http://arxiv.org/abs/2502.15432v1
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2025-02-25
Hot Topic
Farewell message from Jeffrey Fawcett
Our colleague, Jeffrey Fawcett will move on to a new career as a Chief Scientist at Regional Fish Institute, Ltd. as of March 1st, 2025. We all will miss him and wish him the best of luck in his latest endeavor. Here is a message from Jeffrey Fawcett: I will be moving to Kyoto to work at a company called Regional Fish from March. I will also most likely have a joint position at Kyoto University at a lab funded by the company. The company was started a few years ago mostly be people from Kyoto University, Graduate School of Agriculture, where I did my study, and specializes in breeding and developing fish and aquatic species using genome editing and various other techniques. My task will mainly be to perform genomic data analysis for the company, although I will also have some freedom to pursue my own research. I am looking forward to the new challenge to utilize my expertise and work for a company whose I mission I can identify with. I have been in iTHEMS for exactly 7 years, which say how much I enjoyed and appreciated the setup of iTHEMS. I remember some people telling me its their first time meeting a biologist, whereas I never imagined I would ever have the opportunity to enjoy talks on pure mathematics and theoretical physics. I would like to thank all the people involved in iTHEMS and hopefully I will be able to visit iTHEMS from time to time and keep up the connection.
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2025-02-25
Seminar Report
Visit by ASCENT-6E high school students on January 13, 2025
On Monday, January 13th, 2025, we were glad to receive the visit of 15 high school students (13 female and 2 male) enrolled in the STELLA Program ASCENT-6E of Chiba University. The students, accompanied by the Program Director Prof. Jun Nomura, Prof. Atsushi Tsuji, and Program Coordinators Prof. Qian Wang and Prof. Hina Morishige, were welcome to a one-day workshop organized by iTHEMS members. The workshop consisted of a series of presentations in which iTHEMS members talked about some of the fundamental, yet unresolved, questions about our universe. We covered topics ranging from mathematics, biology, physics, and philosophy of science. The objective was to promote the curiosity of students towards science, using iTHEMS as an example of how scientists from different disciplines may interact and do research together under the same roof. We also took the chance to advertise the different RIKEN programs for young researchers and encouraged the students to follow their dreams of becoming professional scientists. During lunchtime and the interactive sessions, we also enjoyed nice opportunities to converse directly with the students, listen to their particular interests, and answer their questions. This visit by the STELLA program ASCENT-6E students was an invaluable opportunity for us at iTHEMS to understand the current situation of young students, their motivations, and their innovative ideas. For the sake of promoting love for science, inclusivity in academia, and a closer interaction with society, we hope that we can create more bridges between the iTHEMS members and the young students in the future. We are glad that the workshop was a success. Please see the webpage of STELLA Program ASCENT-6E to read some of the comments that students made regarding their visit to iTHEMS. Reported by José Said Gutiérrez-Ortega
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2025-02-25
Seminar Report
Theories of Astrophysical Big Bangs 2025 on February 17, 2025
The international workshop “Theories of Astrophysical Big Bangs 2025” was held at RIKEN from February 17 to 19. During the workshop, Daniel Kasen (UC Berkeley), who is currently on sabbatical at RIKEN, delivered a special lecture on supernovae and kilonovae. In addition, 25 invited talks were presented, allowing participants to share the latest advancements in the field of Astrophysical Big Bangs. The workshop also featured 33 poster presentations, showcasing the diverse range of research in the field and fostering extensive discussions among participants. A total of 83 participants from six countries, including Japan, registered for the workshop. This event was supported by the JST ASPIRE project for top scientists: “RIKEN-Berkeley Mathematical Quantum Science Initiative”, which particularly contributed to strengthening research collaboration between RIKEN and UC Berkeley. The workshop is expected to serve as a catalyst for future joint research endeavors. Reported by Shigehiro Nagataki
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2025-02-20
Paper of the WeekWeek 4, February 2025
Title: Systematic study of the composition of Type I X-ray burst ashes: Neutron star structure v.s. Reaction rate uncertainties Author: Guoqing Zhen, Helei Liu, Akira Dohi, Guoliang Lü, Nobuya Nishimura, Chunhua Zhu, Renxin Xu arXiv: http://arxiv.org/abs/2502.10992v1 Title: Chiral symmetry restoration in QC_2D from effective model using the functional renormalization group Author: G. Fejos, D. Suenaga arXiv: http://arxiv.org/abs/2502.10134v1 Title: Birational Transformations and 2d (0,2) Quiver Gauge Theories beyond Toric Fano 3-folds Author: Dongwook Ghim, Minsung Kho, Rak-Kyeong Seong arXiv: http://arxiv.org/abs/2502.08741v1 Title: Numerical evidence for a CP broken deconfined phase at $θ=π$ in 4D SU(2) Yang-Mills theory through simulations at imaginary $θ$ Author: Mitsuaki Hirasawa, Masazumi Honda, Akira Matsumoto, Jun Nishimura, Atis Yosprakob arXiv: http://arxiv.org/abs/2502.09115v2
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2025-02-20
Seminar Report
Pebbles in Planet Formation on February 10-13, 2025
From February 10 to 13, the workshop "Pebbles in Planet Formation" featured a diverse range of topics, including dust theory, solar system small body exploration, dust experiments, simulations of planetesimal formation via instabilities, and observations of protoplanetary disks. The program included six keynote talks, 40 contributed talks, and 18 poster presentations. Ample time was allocated for coffee breaks and discussion sessions, fostering in-depth conversations on various topics. In particular, the workshop reaffirmed the importance of collaboration between experimental groups in Germany and experimental and theoretical groups in Japan. As a result, we have established a foundation for ongoing communication and future cooperation. Reported by Misako Tatsuuma
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2025-02-13
Paper of the WeekWeek 3, February 2025
Title: Physics-Conditioned Diffusion Models for Lattice Gauge Theory Author: Qianteng Zhu, Gert Aarts, Wei Wang, Kai Zhou, Lingxiao Wang arXiv: http://arxiv.org/abs/2502.05504v1
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2025-02-10
Hot TopicFarewell message from Nozomi Kakinuma
Our administrative staff member, Nozomi Kakinuma, will be leaving RIKEN on February 14 to return to academic research. We will greatly miss her and wish her all the best in her future endeavors. Here is a message from Nozomi: Since April last year, I have been part of iTHEMS as a staff member in the iTHEMS Promotion Office. However, I have recently decided to pursue a career in research. Through coffee meetings, where researchers passionately discussed their work and explained it in an accessible way, I came to deeply appreciate both the excitement and significance of fundamental research. Inspired by these experiences, I am now committed to dedicating myself to research. I am truly grateful for all the support and guidance I have received. Thank you very much.
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2025-02-10
Press Release
Who Is at Higher Risk of Progression from Acute Liver Injury to Acute Liver Failure?
A collaborative research group, including Professor Shingo Iwami (Visiting Scientist, iTHEMS / Professor, Graduate School of Science, Nagoya University), has applied artificial intelligence (AI) technology to clinical research. Through joint research, they discovered that patients with acute liver injury can be classified into three groups based on their treatment response. Furthermore, they successfully developed the world's first AI model capable of predicting which group a patient belongs to using clinical data such as initial blood test results. For more details, please visit Kyushu University’s website via the related links.
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2025-02-06
Paper of the WeekWeek 2, February 2025
Title: Investigating the Bouncing Barrier with Collision Simulations of Compressed Dust Aggregates Author: Haruto Oshiro, Misako Tatsuuma, Satoshi Okuzumi, Hidekazu Tanaka arXiv: http://arxiv.org/abs/2502.03107v1 Title: Renormalization-group approach to the Kohn-Luttinger superconductivity: Amplification of the pairing gap from $\ell^4$ to $\ell$ Author: Yuki Fujimoto arXiv: http://arxiv.org/abs/2502.01169v1 Title: $NJ/ψ$ and $Nη_c$ interactions from lattice QCD Author: Yan Lyu, Takumi Doi, Tetsuo Hatsuda, Takuya Sugiura arXiv: http://arxiv.org/abs/2502.00054v1 Title: Identification of finite circular metric spaces by magnitude and Riesz energy Author: Hiroki Kodama, Jun O'Hara arXiv: http://arxiv.org/abs/2408.06091v3 Title: Computing theta-dependent mass spectrum of the 2-flavor Schwinger model in the Hamiltonian formalism Author: Akira Matsumoto, Etsuko Itou, Yuya Tanizaki arXiv: http://arxiv.org/abs/2501.18960v2 Title: Novel Lattice Formulation of 2D Chiral Gauge Theory via Bosonization Author: Okuto Morikawa, Soma Onoda, Hiroshi Suzuki arXiv: http://arxiv.org/abs/2501.18949v1 Title: Biological invasion by the cycad-specific scale pest Aulacaspis yasumatsui (Diaspididae) into Cycas revoluta (Cycadaceae) populations on Amami-Oshima and Okinawa-jima, Japan Author: Benjamin E. Deloso, José Said Gutiérrez-Ortega, Jui-Tse Chang, Yasuko Ito-Inaba, Anders J. Lindström, L. Irene Terry, John Donaldson, William Tang, Ronald D. Cave, Jorge Antonio Gómez-Díaz, Vanessa M. Handley, M. Patrick Griffith, Thomas E. Marler Journal Reference: Plant Species Biology doi: https://doi.org/10.1111/1442-1984.12505 Title: Spacetime profile of electromagnetic fields in intermediate-energy heavy-ion collisions Author: Hidetoshi Taya arXiv: http://arxiv.org/abs/2501.18171v1
63 news in 2025