ニュース

47件のニュース / 2026年

2026-04-21
受賞情報

Keiya Hirashima received FY2025 RIKEN Research and Technology Incentive Award (RIKEN OHBU Award 理研桜舞賞)

Keiya Hirashima (Special Postdoctoral Researcher, iTHEMS) has been awarded the FY2025 RIKEN Research and Technology Incentive Award (RIKEN OHBU Award). The RIKEN OHBU Award is presented to early-career researchers and staff members at RIKEN who have demonstrated outstanding achievements in research and development, research support, or contributions to the promotion and dissemination of research outcomes, through active research activities. Hirashima was recognized for his work entitled “Establishment of galaxy simulations resolving individual stars through the integration of AI surrogate models and large-scale parallel computing.” This work integrates advanced AI surrogate modeling with large-scale parallel computation to enable high-resolution galaxy simulations that resolve individual stars, contributing to a deeper understanding of galaxy formation and evolution. Congratulations, Keiya!
2026-04-21
受賞情報

Masazumi Honda received FY2025 RIKEN Excellent Achievement Award (RIKEN BAIHO Award 理研梅峰賞)

Masazumi Honda (Senior Research Scientist, iTHEMS) has been awarded the FY2025 RIKEN Excellent Achievement Award (RIKEN BAIHO Award). The RIKEN BAIHO Award is presented by the President of RIKEN to individuals who have achieved original and outstanding research and development results that are expected to receive high recognition in academic communities, or who have made distinguished contributions to research support both within and outside the institute. Honda was recognized for his work entitled “Development of non-perturbative methods in quantum field theory and quantum gravity.” This work develops novel theoretical approaches to analyze strongly coupled phenomena in quantum field theory and quantum gravity, and is expected to contribute to the advancement of fundamental physics through a deeper understanding of non-perturbative dynamics. Congratulations, Masazumi!
2026-04-21
受賞情報

シュパイデル玲雄理研ECLユニットリーダーが「SMBE Early-Career Excellence Award」を受賞

iTHEMS 数理基礎部門数理遺伝学理研ECL研究ユニットのシュパイデル玲雄理研ECLユニットリーダーは、2026年3月12日、「2026 SMBE Early-Career Excellence Award」を受賞しました。本賞は、分子生物学・進化学分野の国際学会SMBEが、革新的な研究を通じて分野の発展に貢献し、教育やアウトリーチなどの活動において学会の理念を体現している研究者に授与するものです。シュパイデルユニットリーダーは、数理的手法を用いた遺伝情報解析の研究を進め、分子進化や集団遺伝学の分野に新たな知見をもたらしてきました。今回の受賞は、こうした研究の成果と分野への貢献が評価されたものです。
2026-04-16
今週の論文
Week 3, April 2026

Title: Generalised (bi-)Hamiltonian structures of hydrodynamic type and (bi-)flat F-manifolds Author: Paolo Lorenzoni, Zhe Wang arXiv: http://arxiv.org/abs/2604.12819v1 Title: Interaction-powered Type Ibn Supernovae as a Transient PeVatron Candidate: The Case of SN 2023uqf Author: Ryo Sawada, Yusuke Inoue, Yosuke Ashida arXiv: http://arxiv.org/abs/2604.12496v1 Title: Exact SL(2,Z)-Structure of Lattice Maxwell Theory with $θ$-term in Modified Villain Formulation Author: Shoto Aoki, Yoshio Kikukawa, Toshinari Takemoto arXiv: http://arxiv.org/abs/2604.08736v1
2026-04-09
受賞情報

澤田涼基礎特別研究員が宇核連若手奨励賞を受賞

理化学研究所数理創造研究センター（iTHEMS）基礎特別研究員の澤田涼氏が、第2回宇宙核物理連絡協議会（宇核連）若手奨励賞の受賞者に2026年3月31日付で選ばれました。今回の受賞対象となった研究は、過去の超新星に起因する宇宙線環境が地球型惑星の形成に与える影響に関するものです [1]。
2026-04-09
受賞情報

土肥明基礎科学特別研究員が宇核連若手奨励賞を受賞

理化学研究所開拓研究所基礎科学特別研究員の土肥明氏（iTHEMS 兼務）が、第2回宇宙核物理連絡協議会（宇核連）若手奨励賞の受賞者に2026年3月31日付で選ばれました。今回の受賞対象となった論文は、クロックバースターの理論研究に関するものです[1]。また、本研究成果は、2023年11月11日に理化学研究所開拓研究所玉川高エネルギー宇宙物理研究室が主導して打ち上げた、世界初の超小型汎用X線衛星 NinjaSat による最初の科学成果でもあります。これについての詳細は、関連リンクより理化学研究所開拓研究所のプレスリリースをご覧ください。
2026-04-09
今週の論文
Week 2, April 2026

Title: Twisted doughnuts: Thick disk torus around equatorial asymmetric black hole Author: Che-Yu Chen, Eva Hackmann, Audrey Trova arXiv: http://arxiv.org/abs/2604.05604v1 Title: Gauss law codes and vacuum codes from lattice gauge theories Author: Javier P. Lacambra, Aidan Chatwin-Davies, Masazumi Honda, Philipp A. Hoehn arXiv: http://arxiv.org/abs/2604.06087v1 Title: Reconstruction of fast-rotating neutron star observables with the neural network Author: Wen Liu, Lingxiao Wang, Zhenyu Zhu arXiv: http://arxiv.org/abs/2604.05428v1 Title: Electroweak Doublet Dark Matter for a Galactic Halo Gamma-Ray Excess Author: Yasunori Nomura, Tomonori Totani arXiv: http://arxiv.org/abs/2604.05016v1 Title: Cosmological collider signals of modular spontaneous CP breaking Author: Shuntaro Aoki, Alessandro Strumia arXiv: http://arxiv.org/abs/2604.05548v1 Title: Mechanochemical instabilities drive digit morphogenesis in organoids Author: Rio Tsutsumi, Antoine Diez, Steffen Plunder, Ryuichi Kimura, Shinya Oki, Kaori Takizawa, Rei Nakano, Haruhiko Akiyama, Ritsuko Takada, Shinji Takada, Marco Musy, James Sharpe, Mototsugu Eiraku doi: https://doi.org/10.1101/2025.08.31.673315 Title: Multi-field oscillons/I-balls in the Friedberg-Lee-Sirlin model Author: Kai Murai, Tatsuya Ogawa, Fuminobu Takahashi arXiv: http://arxiv.org/abs/2604.04494v1 Title: Exponentially Long Evaporation of Noncommutative Black Hole Author: Pei-Ming Ho, Wei-Hsiang Shao, Takuya Yoda arXiv: http://arxiv.org/abs/2604.04774v1 Title: Type-IV 't Hooft Anomalies on the Lattice: Emergent Higher-Categorical Symmetries and Applications to LSM Systems Author: Tsubasa Oishi, Hiromi Ebisu arXiv: http://arxiv.org/abs/2604.02856v1 Title: Continuous-time evolution via probabilistic angle interpolation and its applications Author: Tomoya Hayata, Yuta Kikuchi arXiv: http://arxiv.org/abs/2604.02854v1 Title: Phase transitions in parametrized quantum circuits Author: Xiaoyang Wang, Han Xu, Lukas Broers, Tomonori Shirakawa, Seiji Yunoki arXiv: http://arxiv.org/abs/2603.27532v1 Title: Angular momentum transport in the convection zone of a 3D MHD simulation of a rapidly rotating core-collapse progenitor Author: Ryota Shimada, Lucy O. McNeill, Vishnu Varma, Keiichi Maeda, Takaaki Yokoyama, Bernhard Müller arXiv: http://arxiv.org/abs/2603.26550v1 Title: Cosmology from asymptotically safe Proca theories Author: Carlos Pastor-Marcos, Lavinia Heisenberg, Álvaro Pastor-Gutiérrez, Jan M. Pawlowski, Manuel Reichert arXiv: http://arxiv.org/abs/2604.01090v1 Title: Lindbladian Simulation with Commutator Bounds Author: Xinzhao Wang, Shuo Zhou, Xiaoyang Wang, Yi-Cong Zheng, Shengyu Zhang, Tongyang Li arXiv: http://arxiv.org/abs/2603.28602v1 Title: Disentangling the interactive effects of anthropogenic disturbances on biodiversity Author: Isaac Planas-Sitjà, Ryosuke Iritani, Adam L. Cronin arXiv: http://arxiv.org/abs/2603.29116v1 Title: Gravitational waves from gaps of neutron stars Author: Akira Dohi, Asuka Ito, Shota Kisaka arXiv: http://arxiv.org/abs/2603.29514v1 Title: Universal Non-Gaussian Signatures from Transient Instabilities Author: Shuntaro Aoki, Diederik Roest, Denis Werth arXiv: http://arxiv.org/abs/2604.01035v1 Title: Evaluating Phylogenetic Comparative Methods under Reticulate Evolutionary Scenarios Author: Lydia Morley, Emma Lehmberg, Sungsik Kong arXiv: http://arxiv.org/abs/2603.25986v1 Title: Segmentation of monotone data by Kobayashi-Warren-Carter type total variation energies Author: Yoshikazu Giga, Ayato Kubo, Hirotoshi Kuroda, Koya Sakakibara arXiv: http://arxiv.org/abs/2603.28078v2 Title: Zeta Zeros in a Narrow Vertical Box Author: Daniel A. Goldston, Ade Irma Suriajaya arXiv: http://arxiv.org/abs/2603.28104v1 Title: Finite-nuclear-size effect for hydrogenlike ions under high external pressure Author: Dengshan Liu, Huihui Xie, Pengxiang Du, Tianshuai Shang, Jian Li, Jiguang Li, Tomoya Naito arXiv: http://arxiv.org/abs/2603.22901v1
2026-04-06
今週の注目人物

Self-introduction: Yuta Hamada

I am interested in particle physics such as string theory and early universe cosmology. Recently, I am working on identifying consistent gravitational effective field theories that can be ultraviolet completed. Additionally, I am interested in applying AI and quantum computing to string theory and quantum field theory.
2026-04-02
ホットトピック

KEK-iTHEMS Workshop “Concepts of Quantum and Spacetime” on March 9, 2026

We held the workshop “Concepts of Quantum and Spacetime” (at KEK in Japan from 9 to 12 March 2026), a joint workshop organized by KEK Theory Center and RIKEN iTHEMS. The two fundamental questions, “What is quantum?” and “What is spacetime?”, are deeply intertwined. The workshop discussed the question “How can quantum theory and spacetime be understood in a consistent manner?” from a fundamental and broad perspective and shared various ideas with open minds, to find directions guiding quantum theory over the next 100 years. The topics were diverse: foundations of quantum theory, quantum gravity, emergence of spacetime, formulation of semi-classical gravity, experimental aspects of fundamental properties in nature, and foundations of quantum many-body systems and thermodynamics. Around 90 researchers from various countries, generations, and fields came together. (Around 40% of these were from overseas.) The 14 keynote speakers—many of whom are rarely seen in Japan—shared their visions on quantum theory and spacetime. (The talk slides are available in the website.) The 13 selected short talks and the 22 poster presentations were of a high standard, leading to lively discussions; we also held a poster award competition. Interestingly, the disagreements and confusion arising from differences in their expertise and viewpoints actually gave rise to new discussions and ideas. This was likely due to the open atmosphere of sincere engagement that emerged because the thema was not confined to specific methods or theoretical frameworks. Furthermore, small yet significant touches—such as providing boxed lunches to keep the lively atmosphere of the lecture hall going during the lunch break, and setting up whiteboards in open spaces to encourage discussion—proved effective. These efforts fostered constant, natural interaction and lively discussion throughout the venue. Participants did not merely listen; they truly shaped the workshop. (Visit the website to see photos during the event.) Many participants commented that it was an interesting and wonderful workshop. We also received feedback such as, “I gained ideas for future research,” and “This provided valuable insights for organizing future workshops.” These are the result of the deep curiosity shared by all participants regarding fundamental questions, “What is quantum?” and “What is spacetime?” It is precisely such curiosity that will naturally give rise to new ideas and collaborative research and connect the world. I hope that workshops embodying a similar spirit will be held around the world on a variety of themes in the future. Reported by Yuki Yokokura, chair of organizing committee.
2026-04-02
今週の論文
Week 1, April 2026

Title: Nonlocal operators on the lattice for the Higgs-confinement phase transition Author: Yusuke Shimada, Arata Yamamoto Journal Reference: J.Subatomic Part.Cosmol. 5, 100267 (2026) doi: https://doi.org/10.1016/j.jspc.2025.100267 Title: The 'Forgotten' Neutrons: Implications for the Propagation of High-Energy Cosmic Rays in Magnetized Astrophysical and Cosmological Structures Author: Ellis R. Owen, Kinwah Wu, Yoshiyuki Inoue, Tatsuki Fujiwara, Qin Han, Hayden P. H. Ng arXiv: http://arxiv.org/abs/2603.25060v1 Title: Josephson effects in an interaction-asymmetric junction across the BCS-BEC crossover Author: Tingyu Zhang, Hiroyuki Tajima arXiv: http://arxiv.org/abs/2603.25577v1
2026-04-02
今週の注目人物

Self-introduction: Muzi Hong

I am doing research in cosmology, especially in early universe physics. Recently, I have been working on topics such as inflation, cosmological perturbations, baryogenesis, and dark energy. Cosmology is an interdisciplinary field, and I look forward to discussing various topics in physics with researchers from other fields.
2026-04-02
プレスリリース

量子コンピュータで磁化の規則的振動を観測－133量子ビットの2次元系で実証した量子有用性－

白川知功上級研究員を含む研究グループは、IBMの超伝導量子コンピュータを用いて、133量子ビットの2次元格子上で離散時間結晶および離散時間準結晶が最大100時間ステップ（時間ステップは駆動1周期を１ステップと数えた回数）にわたって安定して実現することを明らかにしました。本研究成果は、古典計算が困難な2次元非平衡量子多体系のデジタル量子シミュレーションに向けた実機検証に貢献すると期待されます。詳細は関連リンクをご覧下さい。
2026-04-01
受賞情報

Yuta Sekino received FY2025 RIKEN Research and Technology Incentive Award (RIKEN OHBU Award 理研桜舞賞)

Yuta Sekino (Postdoctoral Researcher, iTHEMS) has been awarded the FY2025 RIKEN Research and Technology Incentive Award (RIKEN OHBU Award). The RIKEN Ohbu Award is presented to early-career researchers and staff members at RIKEN who have demonstrated outstanding achievements in research and development, research support, or contributions to the promotion and dissemination of research outcomes, through active research activities. Sekino was recognized for his proposal entitled “Quantum simulation of spin transport using ultracold atomic gases.” This work presents a novel theoretical framework for simulating and understanding spin transport phenomena in quantum many-body systems using ultracold atom platforms, and is expected to contribute to the advancement of quantum simulation and quantum condensed matter physics. Congratulations, Yuta!
2026-03-31
ホットトピック

Farewell message from Takashi Satomi

Our colleague, Takashi Satomi, will be joining Tokyo Denki University as a Lecturer starting April 2026. We will all miss him and wish him the best of luck in this new endeavor. Here is a message from Takashi: I would like to share that I will be leaving my position as an SPDR at iTHEMS. Although my term was originally planned to continue, I have decided to end it early as I will start a new position as a lecturer at Tokyo Denki University from April. I have been a member of iTHEMS as an SPDR from April 2024 to March 2026. During this time, I greatly enjoyed the open and interdisciplinary environment. Discussions with researchers from different fields gave me many new ideas and perspectives, and these experiences have been very valuable for my research. I would like to express my sincere thanks to all the members at iTHEMS for their support and kindness. From April, I will continue to be affiliated with iTHEMS as a visiting researcher. I hope to continue discussions and collaborations in the future. Thank you very much for everything.
2026-03-31
ホットトピック

Farewell message from Ryosuke Iritani

Our colleague, Ryosuke Iritani, will be joining the Graduate School of Science, The University of Tokyo, as a Project Associate Professor starting April 1, 2026. We will all miss him and wish him the best of luck in this new endeavor. Here is a message from Ryosuke: I have spent a rewarding seven years at iTHEMS. My research interests and vision have broadened significantly thanks to the research environment here. Since joining iTHEMS in 2019, I have become increasingly interested in learning and applying mathematics to biological questions. Whenever I encounter new mathematical techniques, I naturally consider how they might be applied to biological systems and how they can bridge our fields. Through this process, I have come to appreciate the truly interdisciplinary nature of science. This shift in my mindset was made possible by the opportunity to interact with such a diverse group of researchers. My goal over the next decade is to conduct biological research that also inspires other communities, such as mathematics and physics. I look forward to seeing where this path leads. The year 2020 was an unprecedented time, not only for iTHEMS but for society as a whole. During that period, we frequently discussed how to maintain an open and productive community, considering various ways to foster engagement within iTHEMS. As we move past the pandemic, I realize that navigating those challenges was an invaluable experience. It served as an important reminder that our research is fundamentally driven by human connection, passion, and well-being, and that we are individuals first and foremost. Finally, I would like to thank all the colleagues, technical staff, assistants, promotion office staff, and directors with whom I have been fortunate to work, discuss, chat, and dine. While I cannot list everyone by name here, I am deeply grateful for every interaction that enriched my time at iTHEMS. Special thanks to Adachi-san and Hamazaki-san for our continued collaboration; to Biology Seminar, Math Seminar, and Information Theory WG members for sharing their time and ideas through our daily interactions; to Catherine, Hatsuda-san, and Iso-san for their encouragement and for fostering such a great environment; and finally, to Wada-san for the continuous support in almost all aspects of my time at iTHEMS.
2026-03-31
ホットトピック

Farewell message from Ryo Namba

Our colleague, Ryo Namba, will be joining the Department of Physics, Faculty of Science, Shizuoka University, as a Lecturer starting April 1, 2026. We will all miss him and wish him the best of luck in this new endeavor. Here is a message from Ryo: It has been an incredibly stimulating and encouraging five years since I joined iTHEMS in 2021. When I first arrived, restrictions due to COVID-19 limited how often we could come to the office, and I did not have many opportunities to meet other iTHEMS members in person. However, through online meetings and seminars, I sensed a strong and growing enthusiasm for intellectual exchange within the community. Once these constraints were relaxed, people naturally began to gather, and I had many valuable opportunities to interact with colleagues across a wide range of disciplines, including particle and nuclear physics, biology, and mathematics. It was during this time that I was able to expand my research directions significantly. I had the opportunity to participate in study camps with mathematicians and to organize a couple of intensive lecture series spanning physics and mathematics. These experiences have played a central role in shaping my current research focus. iTHEMS offers a truly unique research environment -- not only in its interdisciplinary nature, but also in its openness to member-driven initiatives such as workshops, seminars, and other academic activities. I am deeply grateful for my time at iTHEMS, and I look forward to building on these experiences in my research and educational aspects at Shizuoka University. I sincerely wish for the continued flourishing and development of iTHEMS, and for its current and future members to enjoy their own vibrant and productive time there.
2026-03-31
ホットトピック
Farewell message from Sotaro Sugishita

Our colleague, Sotaro Sugishita, will be joining Hokkaido University as an Associate Professor starting April 1st, 2026. We will all miss him and wish him the best of luck in this new endeavor. Here is a message from Sotaro: I joined iTHEMS in April 2025 as a research scientist in a cross-appointment position with Kyoto University. Although my time at iTHEMS has been short, I am very grateful for the opportunity to have been part of this unique and inspiring group. Due to my busy work and life in Kyoto, it is a little unfortunate that I did not have many opportunities to visit the Wako campus in person. Nevertheless, every time I visited, I was reminded of what a remarkable place iTHEMS is. There are so many outstanding researchers at iTHEMS, and each visit provided me with new stimulation. The open and interdisciplinary atmosphere of iTHEMS is truly special, and I feel fortunate to have had the experience. I would also like to express my sincere appreciation to the assistants at iTHEMS. Their support was always thoughtful and incredibly supportive, and it helped me greatly throughout. I am deeply grateful not only for the academic environment, but also for the professional and welcoming support system that makes iTHEMS such a pleasant place. I would like to thank everyone at iTHEMS. From April 2026, I will join Hokkaido University as an associate professor. I will also be affiliated with iTHEMS as a visiting researcher. I sincerely look forward to staying in touch and to future interactions and collaborations.
2026-03-31
ホットトピック

Farewell message from Yuta Sekino

Our colleague, Yuta Sekino, will be joining the Institute for Advanced Research at Nagoya University as a YLC Assistant Professor starting April 1st, 2026. We will all miss him and wish him the best of luck in this new endeavor. Here is a message from Yuta: I have been at RIKEN for seven years. Starting this April, I will join the Institute for Advanced Research at Nagoya University as a YLC Assistant Professor. I first joined the Quantum Hadron Physics Laboratory (Hatsuda Lab.) at the Nishina Center in April 2019 as a JSPS fellow, and from that time I also began attending iTHEMS activities. In October 2021, I moved to the Astrophysical Big Bang Laboratory (Nagataki Lab.) at RIKEN Cluster for Pioneering Research and started a concurrent position in iTHEMS. In July 2024, I officially became a member of iTHEMS as a postdoctoral researcher associated with RIKEN Quantum, and a concurrent member in Hamzaki Hakubi Research Team. During my seven years at RIKEN, I have greatly enjoyed the research environment embracing the iTHEMS spirit of "under one roof." Since I was an undergraduate student, I have been interested in interdisciplinary studies because my main research field, cold atoms, is strongly influenced by other subfields of physics, such as solid-state, nuclear, and particle physics. Therefore, I have greatly enjoyed interactions with researchers not only in physics, but also in mathematics, biology, and data science. I have also appreciated the availability of quantum computing resources. Although I am moving to Nagoya University, I will remain affiliated as a visiting scientist. I would like to continue participating in iTHEMS activities, and I look forward to further interactions with everyone. Finally, I would like to express my sincere appreciation to all the researchers and assistants of iTHEMS for their kind support throughout my time at RIKEN.
2026-03-31
ホットトピック

Farewell message from Shigenori Otsuka

Our colleague, Shigenori Otsuka, will be joining the Center for Environmental Remote Sensing, Chiba University, as an Associate Professor starting March 2026. We will all miss him and wish him the best of luck in this new endeavor. Here is a message from Shigenori: I came to RIKEN in January 2013 as a postdoctoral researcher at R-CCS, and I joined iTHEMS as a concurrent member in April 2018. Since then, I have learned a lot from various iTHEMS activities, such as the iTHEMS colloquium series, the lecture series at Nara Women's University, coffee meetings, and collaborations between iTHEMS and Kyoto University. Although my research field, meteorology, has not been a major topic within iTHEMS, I found that we shared many common interests, including fluid dynamics, chaos, data assimilation, and machine learning. After my 13-year career at RIKEN, I moved to Chiba University in March 2026 as an associate professor at the Center for Environmental Remote Sensing. In May 2026, I will return to iTHEMS as a visiting scientist in the Prediction Science Research Team, so please keep in touch. Thank you very much!
2026-03-26
今週の論文
Week 5, March 2026

Title: Solving Functional Renormalization Group Equations with Neural Networks Author: Yang-yang Tan, Wei-jie Fu, Lianyi He, Lingxiao Wang arXiv: http://arxiv.org/abs/2603.21151v1 Title: A robust method for classification of chimera states Author: S. Nirmala Jenifer, Riccardo Muolo, Paulsamy Muruganandam, Timoteo Carletti arXiv: http://arxiv.org/abs/2603.22026v1 Title: An introduction to monitored quantum systems and quantum trajectories: spectrum, typicality, and phases Author: Ryusuke Hamazaki, Ken Mochizuki, Hisanori Oshima, Yohei Fuji Journal Reference: Progress of Theoretical and Experimental Physics, ptag055 (2026) doi: https://doi.org/10.1093/ptep/ptag055 arXiv: http://arxiv.org/abs/2512.19922v2 Title: Confinement without symmetry breaking in chiral gauge theories Author: Haolin Li, Álvaro Pastor-Gutiérrez, Shahram Vatani arXiv: http://arxiv.org/abs/2603.19355v1
2026-03-24
ホットトピック

Farewell message from Kan Kitamura

Our colleague, Kan Kitamura, will be joining the Department of Mathematics, College of Science, Rikkyo University as an Assistant Professor, starting April 1, 2026. We will all miss him and wish him the best of luck in this new endeavor. Here is a message from Kan Kitamura: I joined iTHEMS as a special postdoctoral researcher (SPDR) in April, 2024. It has been a great pleasure to spend these two years in such a wonderful research environment. This department is built on a unique concept where researchers from diverse fields of theoretical science work together under one roof. Being able to casually interact with colleagues from different areas has continually stimulated my intellectual curiosity and provided me with a lot of inspiration. In 2025, iTHEMS transitioned into a center, and I feel fortunate to have been there at that time. The evolving environment kept my research experience fresh and exciting. I feel that my research has progressed well during my time here, and I have no doubt that the creative atmosphere of iTHEMS played a significant role in this. I would like to express my deep gratitude to my colleagues for the discussions, both formal and informal, and to the staff for their support. Although I will be leaving my current position, I will remain affiliated as a visiting scientist, and I hope to continue interacting with all of you. I wish iTHEMS every success and continued growth.
2026-03-19
今週の論文
Week 4, March 2026

Title: Toward bootstrapping tensor-network contractions Author: Seishiro Ono, Yanbai Zhang, Hoi Chun Po arXiv: http://arxiv.org/abs/2603.17856v1 Title: Crowdsourcing Gravitational Waves from Superradiant Axions Author: Sebastian A. R. Ellis, Orion Ning, Nicholas L. Rodd, Jan Schütte-Engel arXiv: http://arxiv.org/abs/2603.15734v1 Title: TracktorLive: an integrated real-time object tracking and response system Author: Pranav Minasandra, Vivek Hari Sridhar, Dominique G Roche, Isaac Planas-Sitjà Journal Reference: bioRxiv 2026.03.12.711471 doi: https://doi.org/10.64898/2026.03.12.711471 Title: Learning Quantum Operator Dynamics from Short-Time Data Author: Jinyang Li, Satoshi Iso, Shunji Matsuura, Lingxiao Wang, Xiaoyang Wang arXiv: http://arxiv.org/abs/2603.14699v1 Title: A low mass and radius neutron star candidate in XTE J1810-189? Author: Shoutao Ban, Helei Liu, Zhaosheng Li, Yupeng Chen, Guoliang Lü, Akira Dohi, Tomoshi Takeda, Hongbin Fan, Chunhua Zhu, Renxin Xu arXiv: http://arxiv.org/abs/2603.12962v1 Title: $\bar{D}$-meson Nucleon Scattering from Lattice QCD at the Physical Point Author: Wren Yamada, Yan Lyu, Kotaro Murakami, Takumi Doi arXiv: http://arxiv.org/abs/2603.12251v1
2026-03-17
受賞情報

小谷元子チームディレクターが日本学士院賞を受賞

理化学研究所数理創造研究センター（iTHEMS）数理展開部門数学応用研究チームの小谷元子チームディレクター（兼務）が、日本学士院賞の受賞者に選ばれました。今回の受賞は、砂田利一氏（明治大学名誉教授、東北大学名誉教授）との共同研究「対称性を持った無限グラフの離散幾何解析」を対象とするものとして、2026年3月12日付で日本学士院より公表されました。授賞理由では、結晶格子の「標準的実現」という概念の導入、それに基づく結晶格子上のランダムウォークの研究、とりわけ中心極限定理や大偏差原理の確立、さらにK4クリスタルの再発見や物質科学への応用の推進などが高く評価されています。これらの成果は、離散幾何解析および離散代数幾何学の発展に、理論・応用の両面から重要な貢献をもたらしました。本受賞の対象となった研究は、小谷チームディレクターが東北大学および東北大学材料科学高等研究所（WPI-AIMR）を拠点として進められた研究成果に基づくものです。iTHEMSは東北大学材料科学高等研究所（AIMR）とともに、2018年に連携拠点「SUURI-COOL (Sendai) AIMR-iTHEMS数理連携研究室」を設置しています。同研究室はAIMR本館3階に置かれ、数理科学の観点から物質・生命・宇宙の解明や社会における基本的な問題の解決を図ることを目的としています。小谷チームディレクターのこのたびのご受賞を、iTHEMS一同、心よりお祝い申し上げます。
2026-03-12
今週の論文
Week 3, March 2026

Title: Effective theory of surface oscillations in self-bound superfluid droplets Author: Jun Mitsuhashi, Keisuke Fujii, Masaru Hongo arXiv: http://arxiv.org/abs/2603.10304v1 Title: Phase diagram of 4D SU(3) Yang-Mills theory at $θ=π$ via imaginary theta simulations Author: Akira Matsumoto, Mitsuaki Hirasawa, Jun Nishimura, Atis Yosprakob arXiv: http://arxiv.org/abs/2603.09604v1 Title: Rovibrational energy levels of H$_2$O by quantum computing Author: Erik Lötstedt, Tamás Szidarovszky arXiv: http://arxiv.org/abs/2603.05795v1 Title: Schwinger effect in QCD and nuclear physics Author: Hidetoshi Taya arXiv: http://arxiv.org/abs/2603.07847v1 Title: Bergman space, Conformally flat 2-disk operads and affine Heisenberg vertex algebra Author: Yuto Moriwaki arXiv: http://arxiv.org/abs/2603.06491v1 Title: Mean-Field Convective Phase Separation under Thermal Gradients Author: Meander Van den Brande, François Huveneers, Kyosuke Adachi arXiv: http://arxiv.org/abs/2603.06214v1 Title: When minor issues matter: symmetries, pluralism, and polarization in similarity-based opinion dynamics Author: Brian Mintz, Daniel Simonson, Dominik Wodarz, Feng Fu, Natalia L. Komarova arXiv: http://arxiv.org/abs/2603.04939v1
2026-03-11
セミナーレポート

RIKEN–Berkeley Workshop on Quantum Gravity 2025 on October 23-24, 2025

The RIKEN–Berkeley Workshop on Quantum Gravity 2025 was held on October 23–24, 2025, at the RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS), RIKEN Wako Campus, Japan. The workshop marked the first meeting of a new collaboration between the Leinweber Institute for Theoretical Physics (LITP) at the University of California, Berkeley and iTHEMS. A total of 38 participants attended the workshop. The workshop brought together researchers working on quantum gravity and related areas to discuss recent developments and future directions in the field. The scientific program featured talks on a range of topics, including quantum aspects of spacetime, black hole physics, holography, and their connections to quantum information and condensed matter physics. The meeting provided an opportunity for researchers from Berkeley, RIKEN, and other institutions to exchange ideas and explore potential collaborations. Discussions during the workshop highlighted current progress in the field and encouraged interactions among participants from different research backgrounds. The workshop served as the first step in strengthening collaboration between LITP and iTHEMS, with the aim of promoting continued exchanges and future joint research activities between the two institutions. The workshop was organized by Gabriele Di Ubaldo (LITP Berkeley and RIKEN iTHEMS), Tetsuo Hatsuda (RIKEN iTHEMS), Masazumi Honda (RIKEN iTHEMS), Satoshi Iso (RIKEN iTHEMS), Masamichi Miyaji (RIKEN iTHEMS), Shigehiro Nagataki (RIKEN iTHEMS) and Yasunori Nomura (LITP Berkeley and RIKEN iTHEMS). Reported by Masamichi Miyaji
2026-03-11
ホットトピック

XIIIth International Symposium on Nuclear Symmetry Energy (NuSym25) on September 8-13, 2025

The XIIIth International Symposium on Nuclear Symmetry Energy (NuSym25) was held from September 8 to 13, 2025, at the Integrated Innovation Building, RIKEN Kobe Campus. The symposium brought together approximately 78 researchers working on nuclear physics, astrophysics, and related fields to discuss recent developments in the study of the nuclear equation of state (EoS) and nuclear symmetry energy. The nuclear symmetry energy plays an important role in understanding properties of neutron-rich nuclear matter, which is relevant for nuclear structure, heavy-ion collisions, and astrophysical phenomena such as neutron stars and their mergers. The symposium aimed to connect experimental, observational, and theoretical efforts across these areas. The scientific program included invited and contributed talks covering a broad range of topics, including nuclear structure and reactions, heavy-ion collision experiments and transport model simulations, microscopic calculations of dense neutron-rich matter, and astrophysical observations of compact stars. Recent progress in multi-messenger observations of neutron stars and their implications for the nuclear equation of state were also discussed. The symposium provided an opportunity for researchers from different communities to exchange ideas and strengthen collaborations in addressing common challenges related to the nuclear equation of state. Following the main scientific sessions, a meeting of the Transport Model Evaluation Project (TMEP) was held to discuss benchmarking and uncertainty quantification in transport model simulations for heavy-ion collisions. Reported by Shuntaro Aoki
2026-03-09
ホットトピック

理化学研究所-奈良女子大学理学部合同ダイバーシティ推進ワークショップ2026が開催されました

奈良女子大学の数学、物理学、化学、生物科学、環境科学など異なるコースの学生たち（学部1回生/2回生/3回生、大学院博士前期課程1回生の合計21名）が3月2日と3月3日の2日間に理研を訪問し、多階層精神疾患研究チーム(CBS)、RIBF施設、光量子制御研究チーム(RQC)を見学、iTHEMSでは大矢めぐみ (iTHEMS医科学データ駆動数理チーム特別研究員)とレオ・シュパイデル（iTHEMS ECLユニットリーダー）の講演を聞きました。それぞれの研究室で、実験機器の近くで最先端の研究の一端に触れるとともに、夕方からの理研研究者との交流会では、iTHEMS研究員に質問したり、研究者の日常生活やキャリアについて知り、学生たちにとって充実した交流と有意義な意見交換の場となりました。このダイバーシティ推進活動は、奈良女子大学理学部と理研iTHEMSが共同で推進する事業として、奈良女子大学での連続講義とセットで行われているものです。
2026-03-05
今週の論文
Week 2, March 2026

Title: Quantum anomaly for benchmarking quantum computing Author: Tomoya Hayata, Arata Yamamoto arXiv: http://arxiv.org/abs/2603.03697v1
2026-03-04
ホットトピック

五神理事長が理研バークレーセンターを訪問

2026年2月26日、理化学研究所理事長の五神真氏が理研バークレーセンターを訪問されました（写真左）。当日は、理研バークレーセンターの設立趣旨および活動コンセプトの紹介、オフィスの視察に続き、UC Berkeley (UCB)およびLawrence Berkeley National Laboratory (LBNL) で研究を行っている理研バークレーフェローとの懇談が行われました（写真右）。フェローからは、それぞれの研究内容に加え、バークレーにおける研究・生活環境についての紹介があり、充実した研究活動の様子や今後のさらなる発展に向けた展望が共有されました。また、センター訪問の前後には、五神理事長と Steve Kahn 氏（UCB数学・物理学部長）、野村泰紀氏(UCB, Leinweber Institute for Theoretical Physics 所長)、村山斉氏(UCB, 物理学部教授)らとの意見交換が行われ、UCBの量子計算機施設の視察も行われました。本訪問を契機として、理研とバークレーの研究者間の連携・交流が一層深化することが期待されます。理研バークレーセンターは、今後も両機関をつなぐ研究交流の拠点として活動を推進してまいります。写真左：理研バークレーセンター看板前にて。左から、磯センター長、五神理事長、Wick Haxton氏、長瀧理研バークレーセンター長、初田領域総括。写真右：理研バークレーフェローとの懇談の様子。左から、Gabriele Di Ubaldo氏、Jan Shuette-Engel氏、金久保優花氏、初田領域総括、磯センター長。
2026-02-26
今週の論文
Week 5, February 2026

Title: Out-of-time-ordered correlators for turbulent fields: a quantum-classical correspondence Author: Motoki Nakata arXiv: http://arxiv.org/abs/2602.21710v1 Title: Evidence of Nuclear Urca Process in the Ocean of Neutron-Star Superburst MAXI J1752$-$457 Author: Hao Huang, Akira Dohi, Amira Aoyama, Tomoshi Takeda, Nobuya Nishimura arXiv: http://arxiv.org/abs/2602.19018v1 Title: A $y$-ification of Khovanov homology Author: Taketo Sano arXiv: http://arxiv.org/abs/2602.17435v1 Title: Prefactorization algebras for the conformal Laplacian: Central charge and Hilbert Fock space Author: Yuto Moriwaki arXiv: http://arxiv.org/abs/2602.17549v1 Title: Variation in soldier investment is linked to the evolution of termite soldier defense strategies Author: Akiya Satoh, Isaac Planas-Sitjà, Adam L. Cronin, Nobuaki Mizumoto Journal Reference: Evol Ecol 40, 21 (2026) doi: https://doi.org/10.1007/s10682-026-10386-3
2026-02-19
今週の論文
Week 4, February 2026

Title: On the efficiency of pairwise Hamiltonian control to desynchronize the higher-order Kuramoto model Author: Martin Moriamé, Riccardo Muolo, Timoteo Carletti, Maxime Lucas arXiv: http://arxiv.org/abs/2602.15279v1 Title: Quarkyonic matter and hadron-quark crossover from an ultracold atom perspective Author: Hiroyuki Tajima, Kei Iida, Toru Kojo, Haozhao Liang arXiv: http://arxiv.org/abs/2602.14113v1 Title: Estimation of neutron star mass and radius of FRB 20240114A by identification of crustal oscillations Author: Hajime Sotani, Zorawar Wadiasingh, Cecilia Chirenti arXiv: http://arxiv.org/abs/2602.14353v1 Title: Physical Predictions in Closed Quantum Gravity Author: Yasunori Nomura, Tomonori Ugajin arXiv: http://arxiv.org/abs/2602.13387v1 Title: Symmetry Spans and Enforced Gaplessness Author: Takamasa Ando, Kantaro Ohmori arXiv: http://arxiv.org/abs/2602.11696v1 Title: Payoff equivalence and complete strategy spaces of direct reciprocity Author: Philip LaPorte, Christian Hilbe, Nikoleta E. Glynatsi, and Martin A. Nowak Journal Reference: PNAS doi: https://doi.org/10.1073/pnas.2518486123
2026-02-12
今週の論文
Week 3, February 2026

Title: Lifts of cycles in tropical hypersurfaces and the Gamma conjecture Author: Yuto Yamamoto arXiv: http://arxiv.org/abs/2602.08666v1 Title: Comprehensive Table of Calculated Huff Factors Author: Yuichi Uesaka, Tomoya Naito, Shuichiro Ebata, Megumi Niikura arXiv: http://arxiv.org/abs/2602.07501v1 Title: Conformally flat factorization homology in Ind-Hilbert spaces and Conformal field theory Author: Yuto Moriwaki arXiv: http://arxiv.org/abs/2602.08729v1 Title: Optimal interaction functions realizing higher-order Kuramoto dynamics with arbitrary limit-cycle oscillators Author: Norihisa Namura, Riccardo Muolo, Hiroya Nakao Journal Reference: Chaos 36, 023120 (2026) doi: https://doi.org/10.1063/5.0307452 Title: Forecasting Supermassive Black Hole Binary Gravitational Wave Probes: Prospects for Future Pulsar Timing Array and Space-Borne Detectors Author: Katsunori Kusakabe, Yoshiyuki Inoue, Daisuke Toyouchi, Keitaro Takahashi arXiv: http://arxiv.org/abs/2602.06789v1 Title: Quantum statistical functions Author: Haruki Emori arXiv: http://arxiv.org/abs/2602.05821v1
2026-02-05
受賞情報

廣島渚客員研究員が第7回（2026年）米沢富美子記念賞を受賞

廣島渚客員研究員（横浜国立大学准教授）が、第7回（2026年）米沢富美子記念賞を受賞しました。米沢富美子記念賞は、日本物理学会の女性会員を対象に、物理学分野において優れた研究活動を行っている若手・中堅研究者を顕彰・奨励することを目的として設立された賞です。原則として最終学位取得後15年以内の研究者を対象とし、毎年若干名（概ね5名程度）が選出されます。廣島客員研究員は、宇宙の観測や理論モデルをもとに暗黒物質の性質に迫る理論研究に取り組んでおり、宇宙物理学的手法を用いた暗黒物質研究に関する一連の業績が高く評価され、今回の受賞に至りました。
2026-02-05
今週の論文
Week 2, February 2026

Title: Courant-Hilbert deformations of Yang-Baxter sigma models Author: Osamu Fukushima, Takaki Matsumoto, Kentaroh Yoshida arXiv: http://arxiv.org/abs/2602.04662v1 Title: Hurwitz-Radon numbers and proper actions of semisimple Lie groups Author: Kazuki Kannaka, Koichi Tojo arXiv: http://arxiv.org/abs/2602.04544v1 Title: von Neumann entropy of phase space structures in gyrokinetic plasma turbulence Author: Go Yatomi, Motoki Nakata arXiv: http://arxiv.org/abs/2602.00600v1 Title: When higher-order interactions enhance synchronization: the case of the Kuramoto model on random hypergraphs Author: Riccardo Muolo, Hiroya Nakao, Marco Coraggio arXiv: http://arxiv.org/abs/2508.10992v2 Title: Resource-Theoretic Quantifiers of Weak and Strong Symmetry Breaking: Strong Entanglement Asymmetry and Beyond Author: Yuya Kusuki, Sridip Pal, Hiroyasu Tajima arXiv: http://arxiv.org/abs/2601.20924v1 Title: Non-invertible translation from Lieb-Schultz-Mattis anomaly Author: Tsubasa Oishi, Takuma Saito, Hiromi Ebisu arXiv: http://arxiv.org/abs/2601.21625v1 Title: Probing the Diversity of Type Ia Supernova Remnants in 3-D Hydrodynamic Simulations with X-ray Spectral Synthesis Author: Yusei Fujimaru, Shiu-Hang Lee, Gilles Ferrand, Daniel Patnaude, Shigehiro Nagataki, Rüdiger Pakmor, Samar Safi-Harb, Friedrich K. Röpke, Anne Decourchelle, Ivo R. Seitenzahl arXiv: http://arxiv.org/abs/2601.20446v1
2026-02-03
ホットトピック

企画展「ミッション∞インフィニティ」で「Black Hole Recorder」を展示

株式会社ADKマーケティング・ソリューションズは、東京都現代美術館で開催中の企画展「ミッション∞インフィニティ｜宇宙＋量子＋芸術」（2026年1月31日〜5月6日）にて、 iTHEMSと制作した体験型サイエンスアート作品「Black Hole Recorder（ブラックホール・レコーダー）」を出展中です。この作品は、量子ブラックホール理論に着想を得た未来の情報ストレージのプロトタイプ模型。膨大なデータを蓄えるブラックホールをモチーフに、人間の声や音を記録し、遠い未来や宇宙へ届けるというコンセプトで展示されています。企画展では、宇宙や量子とアートを融合した作品を通じて、「見えない世界」や未来の可能性を体感できます。詳細は関連リンクをご覧下さい。
2026-01-29
今週の論文
Week 5, January 2026

Title: Direct numerical simulation of the 't Hooft partition function and (de)confining phases Author: Okuto Morikawa, Hiroshi Suzuki arXiv: http://arxiv.org/abs/2601.20159v1 Title: Generalizable Equivariant Diffusion Models for Non-Abelian Lattice Gauge Theory Author: Gert Aarts, Diaa E. Habibi, Andreas Ipp, David I. Müller, Thomas R. Ranner, Lingxiao Wang, Wei Wang, Qianteng Zhu arXiv: http://arxiv.org/abs/2601.19552v1 Title: Well-posedness of the Langmuir film problem Author: Yoichiro Mori, Shinya Okabe, Koya Sakakibara arXiv: http://arxiv.org/abs/2601.16482v1 Title: Exploring Noisy Quantum Thermodynamical Processes via the Depolarizing-Channel Approximation Author: Jian Li, Xiaoyang Wang, Marcus Huber, Nicolai Friis, Pharnam Bakhshinezhad arXiv: http://arxiv.org/abs/2601.16317v1
2026-01-29
受賞情報

エリック・ローツステット上級研究員が Physical Review Journals 優秀査読者（2026 Outstanding Referee）に選出

エリック・ローツステット上級研究員が、米国物理学会（American Physical Society: APS）が発行する学術誌 Physical Reviewにおける2026 Outstanding Refereeに選出されました。 Outstanding Referee プログラムは、Physical Review 誌の査読活動において特に顕著な貢献を行った研究者を表彰する制度で、2008年に創設されました。査読を通じて論文の質向上や可読性の改善に寄与し、学術誌の高い基準を支える重要な役割を担った研究者に授与されます。年間約10万人にのぼるアクティブな査読者の中から、報告書の質、件数、迅速性などを基準に、ごく限られた研究者が選出されます。ローツステット上級研究員は、計算物理学、計算化学、強光子場科学、量子コンピューティングなど複数の研究分野で活躍しており、これまでの査読活動における高い専門性と国際的な学術コミュニティへの貢献が評価され、今回の受賞に至りました。
2026-01-22
今週の論文
Week 4, January 2026

Title: Relic of quadrupole deformation produced in a hot neutron star era Author: Yasufumi Kojima, Akira Dohi, Shota Kisaka, Kotaro Fujisawa arXiv: http://arxiv.org/abs/2601.13550v1 Title: Onset of thermalization of q-deformed SU(2) Yang-Mills theory on a trapped-ion quantum computer Author: Tomoya Hayata, Yoshimasa Hidaka, Yuta Kikuchi arXiv: http://arxiv.org/abs/2601.13530v1 Title: Economic complexity and regional development in India: Insights from a state-industry bipartite network Author: Joel M Thomas, Abhijit Chakraborty arXiv: http://arxiv.org/abs/2601.12356v1 Title: Time delay embeddings to characterize the timbre of musical instruments using Topological Data Analysis: a study on synthetic and real data Author: Gakusei Sato, Hiroya Nakao, Riccardo Muolo Journal Reference: Eur. Phys. J. Spec. Top. (2026) doi: https://doi.org/10.1140/epjs/s11734-026-02132-1 Title: Shadow signatures and energy accumulation in Lorentzian-Euclidean black holes Author: Emmanuele Battista, Salvatore Capozziello, Che-Yu Chen arXiv: http://arxiv.org/abs/2601.10806v1 Title: Insights from the “Women in Evolutionary Biology Workshop” on gender equality in science Author: Stella Kyomen, Maria Alejandra Ramirez, Nikoleta E Glynatsi, Gisela T Rodríguez-Sánchez, Amanda de Azevedo-Lopes Journal Reference: Evolution doi: https://doi.org/10.1093/evolut/qpaf255
2026-01-15
ホットトピック

iTHEMS Colloquium by Hiroki R. Ueda on October 10, 2025

On October 10, 2025, Dr. Hiroki Ueda, Professor at the University of Tokyo’s Graduate School of Medicine and former Team Leader at RIKEN Center for Biosystems Dynamics Research (BDR), delivered a splendid iTHEMS Colloquium talk on the Wako campus. His lecture, titled “Why Do We Sleep? The Role of Calcium and Phosphorylation in Sleep,” attracted a wide audience—not only researchers from iTHEMS but also colleagues from other RIKEN centers, including the Pioneering Research Institute (PRI) and the Center for Brain Science (CBS), as well as administrative staff. The talk was highly engaging and accessible to specialists and non-specialists alike. Dr. Ueda began with an overview of the long history of sleep research and the major unsolved questions that continue to inspire the field. He then presented his group’s recent discoveries on the role of calcium in sleep regulation. He also introduced a new theoretical framework—the WISE (Wake Inhibition Sleep Enhancement) mechanism—together with its mathematical modeling. Because sleep is closely connected to our daily lives, the audience had many questions from diverse perspectives, and Dr. Ueda kindly addressed each of them in detail. During and after the colloquium, including at the dinner that followed, we had stimulating discussions with him about his group’s model and potential new directions for sleep research and related areas of life science. We are deeply grateful to Dr. Ueda for his inspiring lecture and for sharing his broad expertise with our community. (Photos: courtesy of Assistant Chikako Ota, RIKEN iTHEMS.) Reported by Gen Kurosawa
2026-01-15
プレスリリース

「バタフライ効果」を制御する新原理

理化学研究所（理研）計算科学研究センターデータ同化研究チームの三好建正チームプリンシパル（数理創造研究センター予測科学研究チームチームディレクター）は、「バタフライ効果」で知られる決定論的カオスの予測可能性の限界を逆手に取り、効率的にカオスを制御する新たな数理的枠組みを構築しました。気象予測の根幹を成すデータ同化（観測を用いてモデルを自然の振る舞いに同期させるプロセス）とカオスの制御が数学的に双子の関係にあることを示す「双対性原理」を提唱しました。カオス自体を抑えるのではなく、カオス特有の高い感度を利用して、わずかな「介入」で扱いやすい「目標軌道」に自然の振る舞いを同期させます。これにより、予測限界を超えてカオスを制御する道筋を理論的に示しました。本研究成果は、例えば、モデルで描いた「台風が被害をもたらさないシナリオ（目標軌道）」に現実の自然現象を同期させるためにわずかな変化（介入）を加えるといった、将来の極端気象を回避するための防災・減災研究に向けた理論的な道筋を示すとともに、生態系や経済学など、カオス的な振る舞いを示すさまざまな分野での応用が期待されます。詳細は関連リンクをご覧下さい。
2026-01-15
プレスリリース

3,000億粒子の天の川銀河シミュレーションをAI×富岳で実現

平島敬也基礎科学特別研究員を含む国際共同研究グループは、人工知能（AI）とスーパーコンピュータ「富岳」のシステム全体（約15万ノード）を利用し、星や星間ガスなどを表す3,000億個の粒子を用いて星一つ一つまでを分解した世界最高解像度となる天の川銀河のシミュレーションを実現しました。本研究成果により、天の川銀河の渦状腕構造（渦巻銀河が持つ、円盤上で中心から外側に向かって渦を巻いて伸びる腕状の構造）や、銀河内の元素の循環、太陽系や生命の材料の起源解明に貢献することが期待されます。詳細は関連リンクをご覧下さい。
2026-01-15
今週の論文
Week 3, January 2026

Title: Equivalence of Doubly Periodic Tangles Author: Ioannis Diamantis, Sofia Lambropoulou, Sonia Mahmoudi arXiv: http://arxiv.org/abs/2310.00822v2 Title: Relaxation Process During Complex Time Evolution In Two-Dimensional Integrable and Chaotic CFTs Author: Chen Bai, Weibo Mao, Masahiro Nozaki, Mao Tian Tan, Xueda Wen arXiv: http://arxiv.org/abs/2601.09290v1 Title: Dissipative ground-state preparation of a quantum spin chain on a trapped-ion quantum computer Author: Kazuhiro Seki, Yuta Kikuchi, Tomoya Hayata, Seiji Yunoki arXiv: http://arxiv.org/abs/2601.08137v1 Title: Coherence of Supermassive Black Hole Binary Demographics with the nHz Stochastic Gravitational Wave Background Author: Katsunori Kusakabe, Yoshiyuki Inoue, Daisuke Toyouchi arXiv: http://arxiv.org/abs/2510.10548v2 Title: Extending the Handover-Iterative VQE to Challenging Strongly Correlated Systems: $N_2$ and Fe-S Cluster Author: Pilsun Yoo, Kyungmin Kim, Eyuel E. Elala, Shane McFarthing, Aidan Pellow, Johanna I. Fuks, Doo Hyung Kang, Pratanphorn Nakliang, Jaewan Kim, Himadri Pathak, Tomonori Shirakawa, Seiji Yunoki, June-Koo Kevin Rhee arXiv: http://arxiv.org/abs/2601.06935v1 Title: Dynamics of Interfaces in the Two-Dimensional Wave-Pinning Model Author: Shunsuke Kobayashi, Koya Sakakibara, Taikei Uechi arXiv: http://arxiv.org/abs/2601.04746v1
2026-01-08
ホットトピック

RIKEN–IBS Joint Workshop on Mathematical Approaches to Nature Held in Daejeon, Korea, December 9–12, 2025

In December 9–12, 2025, a collaborative workshop jointly organized by the Institute of Basic Science (IBS, Korea) and RIKEN was held in Daejeon, Korea. The workshop aimed to explore the unifying mathematical principles that underlie diverse natural phenomena—from the fundamental interactions that shape the universe to the complex behaviors observed in living systems. From RIKEN, iTHEMS researchers including Derek Inman, Ryo Namba, Alvaro Pastor Gutierrez, Shuntaro Aoki, Sungsik Kong, Amaury Micheli, Puttarak Jai-akson, Ryoko Oishi-Tomiyasu, Che-Yu Chen, and Christy Kelly delivered talks. All the presentations were impressive and thoughtfully prepared so that researchers from different fields could follow and appreciate the content. Indeed, there were many stimulating cross-disciplinary questions, and we enjoyed lively discussions over lunches and dinners, accompanied by excellent (and wonderfully spicy) food. Although the workshop was originally designed to foster collaboration between RIKEN and IBS, connections were already present—for example, through Shuntaro Aoki, a physicist at iTHEMS formerly at IBS, and Shingo Gibo, a mathematical biologist at IBS formerly at iTHEMS. This workshop further strengthened these ties and created new ones. The planning and local organization of the workshop were led by the center of Masahide Yamaguchi (IBS), Yusuke Yamada (IBS), and by Yuto Yamamoto and Ryo Namba at RIKEN iTHEMS, with strong support from IBS and the International Collaboration Section of the Global Strategy Division at RIKEN. We are deeply grateful for their dedicated efforts. I hope that the successful interactions fostered through this workshop will continue to develop even further. (Photos: courtesy of Director Satoshi Iso, RIKEN iTHEMS.) Reported by Gen Kurosawa
2026-01-08
今週の論文
Week 2, January 2026

Title: Phases of the $q$-deformed $\mathrm{SU}(N)$ Yang-Mills theory at large $N$ Author: Tomoya Hayata, Yoshimasa Hidaka, Hiromasa Watanabe arXiv: http://arxiv.org/abs/2601.03843v1 Title: Revisiting Spherically Symmetric Spacetime I: Geometro-Hydrodynamics Author: Puttarak Jai-akson, Yuki Yokokura arXiv: http://arxiv.org/abs/2601.03077v1 Title: Exceptional Lines and Excitation of (Nearly) Double-Pole Quasinormal Modes: A Semi-Analytic Study in the Nariai Black Hole Author: Nao Nakamoto, Naritaka Oshita arXiv: http://arxiv.org/abs/2601.00704v1 Title: Gauge Symmetry in Quantum Simulation Author: Masanori Hanada, Shunji Matsuura, Andreas Schafer, Jinzhao Sun arXiv: http://arxiv.org/abs/2512.22932v1
2026-01-08
セミナーレポート

GW-EOS WG Seminar by Pierbiagio Pieri on November 6, 2025

In this seminar, pairing phenomena in three kinds of quantum many-body systems were discussed. First, the speaker reviewed his work on the Bose-Fermi mixture, mainly focusing on the quasiparticles called Fermi-polarons. Second, inhomogeneous pairing fluctuations in a spin-polarized Fermi-Fermi mixture are reviewed. Finally, dissipations called mutual friction arising from interplay between Andreev bound states in the vortex core and delocalized thermal excitations were discussed for strongly interacting Fermi superfluids. Reported by Yuta Sekino
2026-01-06
受賞情報

楠亀裕哉客員研究員が第22回（令和7年度）日本学術振興会賞を受賞

数理創造研究センター数理基礎部門の楠亀裕哉客員研究員（九州大学高等研究院准教授）が、2025年12月16日に第22回（令和7年度）日本学術振興会賞を受賞しました。日本学術振興会賞は、創造性に富み優れた研究能力を有する若手研究者を早い段階で顕彰し、その研究意欲と研究の発展を支援することを目的として設けられた賞です。楠亀客員研究員は、量子重力・量子多体系の境界領域における新手法の開発と応用に関する研究において顕著な成果を挙げてきました。本受賞は、これらの研究成果とその学術的貢献が高く評価されたものです。授賞式は、2026年2月3日に日本学士院講堂で開催される予定です。
2026-01-01
今週の論文
Week 1, January 2026

Title: Geometric phase of exceptional point as quantum resonance in complex scaling method Author: Okuto Morikawa, Shoya Ogawa, Soma Onoda arXiv: http://arxiv.org/abs/2512.24528v1 Title: Tensor Computing Interface: An Application-Oriented, Lightweight Interface for Portable High-Performance Tensor Network Applications Author: Rong-Yang Sun, Tomonori Shirakawa, Hidehiko Kohshiro, D. N. Sheng, Seiji Yunoki arXiv: http://arxiv.org/abs/2512.23917v1 Title: Description of Baryon Mass Spectrum by Open Strings and Diquarks Author: Yuki Fujimoto arXiv: http://arxiv.org/abs/2512.24882v1 Title: Measuring out-of-time-order correlators on a quantum computer based on an irreversibility-susceptibility method Author: Haruki Emori, Hiroyasu Tajima arXiv: http://arxiv.org/abs/2512.22643v1 Title: Error and Disturbance as Irreversibility with Applications: Unified Definition, Wigner--Araki--Yanase Theorem and Out-of-Time-Order Correlator Author: Haruki Emori, Hiroyasu Tajima arXiv: http://arxiv.org/abs/2309.14172v3

47件のニュース / 2026年