News
107 news in 2026
-
2026-09-25
Hot Topic
AI for Science Summer School 2026 Held on August 25–27, 2026
The AI for Science Summer School was held on August 25–27, 2026, at RIKEN Wako Campus, with online participation via Zoom. Jointly organized by the AI as Science Team and the DEEP-IN Working Group, the three-day school brought together more than 40 participants for lectures and hands-on coding sessions exploring how artificial intelligence can support scientific research. The program focused on three practical questions concerning where AI can help address scientific problems, how to choose appropriate methods, and how to apply them effectively. Masato Taki (Rikkyo University/RIKEN) introduced machine learning fundamentals, and Lingxiao Wang (RIKEN/The University of Tokyo) discussed generative modeling. Vinicius Massami Mikuni (Nagoya University) presented foundation models and parameter inference. Naoya Takeishi (The University of Tokyo) covered simulation-based inference. Akinori Tanaka (RIKEN) and Conglong Li (Google DeepMind) explored large language models and their applications to scientific discovery. Hands-on tutorials complemented the lectures. Tutors included Yang-yang Tan (The University of Tokyo), Jinyang Li (KEK/RIKEN), Victor Kawasaki-Borruat (EPFL), and Jingzong Zhang (Fudan University). The sessions covered supervised and unsupervised learning, generative models, data generation, and AI-assisted research workflows. These tutorials connected the lecture material with practical implementation. By combining conceptual introductions with practical exercises, the school offered participants an opportunity to explore how AI methods could be incorporated into their own research. Its emphasis on scientific questions connected the different topics, from interpreting data and generating samples to assisting the research process itself. We thank all lecturers, tutors, participants, and iTHEMS staff for their contributions and support. Reported by Lingxiao Wang
-
2026-09-24
Hot Topic
A simulation of the Milky Way galaxy, utilizing exascale supercomputers and AI, advances to Finals for 2026 ACM Gordon Bell Prize
A research group including Dr. Keiya Hirashima of the RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS) has been selected as a finalist for the 2026 ACM Gordon Bell Prize for large-scale Milky Way galaxy simulations using exascale supercomputers and AI. Further details will be available soon.
-
2026-09-24
Seminar Report
iTHEMS Theoretical Physics Seminar by Masashi Kawahira on September 24, 2026
In this seminar, we discussed whether analogues of 7-branes in type IIB superstring theory can exist in type 0B string theory, a non-supersymmetric counterpart of type IIB theory. Based on the recently proposed self-duality group of type 0B string theory by Baykara, Dudas, and Vafa, the possible existence and properties of such objects were investigated. The talk also stimulated discussion on duality and the interpretation of branes in non-supersymmetric string theory. Reported by Okuto Morikawa
-
2026-09-24
Paper of the WeekWeek 4, September 2026
Title: PR-Smoother: Simulator-Preserving Non-Gaussian Smoothing for Data Assimilation Author: Yuta Tarumi arXiv: http://arxiv.org/abs/2609.26890v1 Title: Geometries of Quantum Field Theories Author: Masahito Yamazaki arXiv: http://arxiv.org/abs/2609.28210v1 Title: Quasinormal-mode redshifts of black holes in galactic halos with radial pressures Author: Che-Yu Chen, Hassan Hassanabadi, Soroush Zare arXiv: http://arxiv.org/abs/2609.27379v1 Title: Ejecta clumps revealed by study of reverse-shocked ejecta through MUSE integral field spectroscopy of SNR 0509-67.5 Author: Priyam Das, Ivo Seitenzahl, J. Martin Laming, Gilles Ferrand, Simon J. Murphy, Ashley Ruiter Journal Reference: PASA, 2026;43:e105 doi: https://doi.org/10.1017/pasa.2026.10255 arXiv: http://arxiv.org/abs/2608.17465v1 Title: Bulk OPE Coefficients of the $E$-Series Virasoro Minimal Models Author: Amaury Lhoste, Jiaxin Qiao, Masahito Yamazaki arXiv: http://arxiv.org/abs/2609.25215v1 Title: Evidence for a Continuous Hadron--Quark Transition in Cold Dense Matter Author: Yong-Jia Huang, Bikai Gao arXiv: http://arxiv.org/abs/2609.22450v1 Title: QCD thermodynamics through the crossover as a gas of confining strings with repulsive interactions Author: Yuki Fujimoto, Volodymyr Vovchenko arXiv: http://arxiv.org/abs/2609.23292v1 Title: Statistical Mechanics of Quarkyonic Matter Author: Marcus Bluhm, Yuki Fujimoto, Marlene Nahrgang arXiv: http://arxiv.org/abs/2604.00247v1 Title: Physical and emergent nonpairwise interactions in oscillator networks: from higher-order phase reduction to coupling design Author: Riccardo Muolo, Hiroya Nakao, Christian Bick arXiv: http://arxiv.org/abs/2609.20632v1
-
2026-09-17
Paper of the WeekWeek 3, September 2026
Title: Deep learning emergent spacetime from fermionic spectral functions in holography Author: Koji Hashimoto, Hyun-Sik Jeong, Keun-Young Kim, Daichi Takeda, Kwan Yun arXiv: http://arxiv.org/abs/2609.18566v1 Title: Quasinormal modes of Kerr-Newman-de Sitter black holes from Heun connection formulae Author: Hideo Furugori, Naotaka Kubo, Hayato Motohashi, Daisuke Yoshida arXiv: http://arxiv.org/abs/2609.17471v1 Title: When the gravity path integral describes a statistical average Author: Gabriele Di Ubaldo, Luca V. Iliesiu, Henry W. Lin, Cynthia Yan arXiv: http://arxiv.org/abs/2609.16113v1 Title: The Role of Completeness in Probing Symmetry Breaking Author: Yuya Kusuki, Hiroyasu Tajima, Shion Yamashika arXiv: http://arxiv.org/abs/2609.16153v1 Title: Designs without disorder: unitary $k$-designs from a single-site bulk defect Author: Samudra Sur, Pratik Nandy arXiv: http://arxiv.org/abs/2609.16140v1 Title: Classifiable C*-algebras have quantum symmetries Author: Kan Kitamura arXiv: http://arxiv.org/abs/2609.16999v1 Title: Effective Dynamics of Inflationary End-of-the-World Branes in AdS$_3$ Author: Kosei Fujiki, Michitaka Kohara, Jason Kristiano, Yu-ki Suzuki, Tadashi Takayanagi arXiv: http://arxiv.org/abs/2609.11643v1 Title: Stokes Phenomena between AdS/CFT and dS/CFT Author: Masazumi Honda, Kotaro Shinmyo arXiv: http://arxiv.org/abs/2609.10677v1 Title: Joint Mitigation of Algorithmic and Physical Errors in Noisy Hamiltonian Simulation Author: Shuo Zhou, Xinzhao Wang, Ruiqi Zhang, Xiaoyang Wang, Yi-Cong Zheng, Tongang Li, Shengyu Zhang arXiv: http://arxiv.org/abs/2609.11508v1 Title: Theoretical Aspects of Direct Waves in Kerr Black Holes: Pole-Splitting Method for Ringdown Analysis Author: Nao Nakamoto, Naritaka Oshita, Hiroki Takeda arXiv: http://arxiv.org/abs/2609.11908v2 Title: Phases in a class of associative memories via hidden neurons Author: Toshihiro Ota, Masato Taki arXiv: http://arxiv.org/abs/2609.10976v1
-
2026-09-15
Hot Topic
Farewell message from Yuto Yamamoto
Our colleague, Yuto Yamamoto, will be joining the Department of Mathematics, School of Science, Institute of Science Tokyo as an Assistant Professor starting in October 2026. We will all miss him and wish him the best of luck in his new endeavor. Here is a message from Yuto: I am very grateful for the opportunity to have been a member of iTHEMS. During my time here, I enjoyed the stimulating research environment and many opportunities to interact with researchers from different fields. I would like to thank all the members and administrative staff of iTHEMS for their support and for making my time here productive and enjoyable. I have learned a lot from seminars, discussions, and informal conversations with colleagues. Although I am leaving iTHEMS, I hope to stay in touch and to have opportunities to meet and collaborate again in the future. I wish iTHEMS and all its members continued success. Thank you very much for everything.
-
2026-09-15
Hot Topic
Farewell message from Kai Murai
Our colleague, Kai Murai, will be joining Tohoku University as an Assistant Professor starting in October 2026. We will all miss him and wish him the best of luck in his new endeavor. Here is a message from Kai: At the end of September, I will leave iTHEMS and move to Tohoku University as an assistant professor. I joined iTHEMS as an SPDR this April. Although my time here was short, it was a very stimulating experience. I especially appreciated the environment where researchers from various fields worked in the same place. It was interesting to be surrounded by research on topics quite different from my own, and I also enjoyed the opportunities to talk with researchers from other fields. I am very grateful to the iTHEMS members who talked with me, as well as to the assistants for all their support. I will come back to iTHEMS for workshops and other occasions, and I look forward to seeing many of you again.
-
2026-09-15
Hot Topic
JST-ASPIRE Symposium Held in Palo Alto
On July 24, 2026, the JST-ASPIRE Symposium, “Strengthening Japan–U.S. Research Collaboration through International Talent Circulation,” was held at the Japan Innovation Campus in Palo Alto, California. Organized by the Japan Science and Technology Agency (JST), the symposium brought together representatives of the Japanese government, principal investigators of ASPIRE projects, early-career researchers conducting research in the United States, and U.S.-based researchers. The program focused on research activities supported by ASPIRE, the experiences of early-career researchers working abroad, and future opportunities for Japan–U.S. research collaboration. A panel discussion also addressed how international researcher mobility can contribute to strengthening research capabilities and building sustainable international networks. Four young researchers participating in the RIKEN–Berkeley Mathematical Quantum Science Initiative—Yuuka Kanakubo, Gabriele Di Ubaldo, Haruki Emori, and Shoto Aoki—gave a joint presentation. They introduced their respective research activities and shared experiences gained through conducting research in the United States, as well as their perspectives on future research and career development. Their diverse research areas, ranging from high-energy and nuclear physics to quantum gravity, quantum information, and lattice gauge theory, reflect the broad scope of the RIKEN–Berkeley collaboration. The symposium provided an opportunity to introduce the activities of the RIKEN–Berkeley Mathematical Quantum Science Initiative within the broader ASPIRE program and to consider the importance of sustained researcher exchange between Japan and the United States. Reported by Shuntaro Aoki
-
2026-09-10
Paper of the WeekWeek 2, September 2026
Title: Magnitude and motivic zeta functions of matroids Author: Junnosuke Koizumi arXiv: http://arxiv.org/abs/2609.07977v1 Title: Asymptotics of Ground States for Helium-Like and Bosonic Atoms in a Two-Cluster Region Author: Yukimi Goto arXiv: http://arxiv.org/abs/2609.08257v1 Title: Quantum-Geometric Meissner Effect in Magnetized Color Superconductors Author: Kazuya Mameda, Noriyuki Sogabe arXiv: http://arxiv.org/abs/2609.07835v1 Title: Theoretical Review on Bulk Properties and Light/Strange Hadron Production in Heavy-Ion Collisions Author: Yuuka Kanakubo arXiv: http://arxiv.org/abs/2609.05815v1 Title: Global Fixed Point Potentials in the Abelian Higgs Model with $N$ flavors Author: Gergely Fejős, Shunsuke Yabunaka arXiv: http://arxiv.org/abs/2609.04938v1 Title: Excitation factors and exceptional points of Kerr-de Sitter quasinormal modes Author: Dario Rossi, Naritaka Oshita, Leonardo Gualtieri, Emanuele Berti arXiv: http://arxiv.org/abs/2609.03009v1 Title: Discretization-Aware Fine-Tuning for Quantum Machine Learning with Chemical Foundation Models Author: Shunji Matsuura, Sonika Johri arXiv: http://arxiv.org/abs/2609.03220v1 Title: Center-twisted Gribov spectra and the finite-volume Gaussian response in the refined Gribov--Zwanziger framework Author: Okuto Morikawa arXiv: http://arxiv.org/abs/2609.03525v1
-
2026-09-08
Hot Topic
Masason Foundation Summer Program Visit to the RIKEN–Berkeley Center on August 11, 2026
Participants in the Masason Foundation’s summer program visited the RIKEN–Berkeley Center at the University of California, Berkeley, on August 11, 2026. The summer program provides young participants with opportunities to broaden their perspectives through visits to universities, research institutions, and other organizations, and through direct interactions with researchers and professionals. The visit began with a tour of the UC Berkeley Physics Department, including an introduction to its history and research environment. This was followed by short presentations by researchers, including Shoto Aoki, Yuka Kanakubo, Gabriele Di Ubaldo, and Akira Dohi, who introduced their research activities to the participants. In the latter part of the program, the participants visited several experimental laboratories at UC Berkeley. Through the presentations, discussions, and laboratory visits, they had an opportunity to learn about a broad range of research activities and to experience firsthand the environment in which cutting-edge research is carried out. The visit provided a valuable opportunity for the young participants to interact directly with researchers at RIKEN and UC Berkeley and to gain a broader perspective on scientific research and possible future career paths. Reported by Shuntaro Aoki
-
2026-09-03
Paper of the WeekWeek 1, September 2026
Title: Dark Matter as the Z_2 Partner of the Standard Model Higgs Boson Author: Yasunori Nomura arXiv: http://arxiv.org/abs/2609.02505v1 Title: Symmetry-Reduced Variational Quantum Simulation of the $U(5)\rightarrow SU(3)$ Quantum Phase Transition in the Interacting Boson Model Author: Faisal Etminan arXiv: http://arxiv.org/abs/2609.00349v1 Title: Detecting Multiple Phase Transitions in Lattice Systems with Intrinsic Dimensions Author: Jie Mei, Tetsuo Hatsuda, Mei Huang, Lingxiao Wang arXiv: http://arxiv.org/abs/2608.29090v1 Title: Two Languages for the Same Resonance: From Nuclear Decay to Black-Hole Ringdown Author: Okuto Morikawa arXiv: http://arxiv.org/abs/2608.29806v1 Title: Quantum Federated Learning Based on Bures--Uhlmann Geometry for Heterogeneous Noisy Clients Author: Haruki Emori, Masaki Uchihara, Yuuki Tokunaga arXiv: http://arxiv.org/abs/2608.28379v1 Title: Local inequalities for $cD$ and $cE$ singularities Author: Chi-Kang Chang, Jheng-Jie Chen, Takuzo Okada arXiv: http://arxiv.org/abs/2608.28372v1 Title: Apéry-type approximations and irrationality measures for certain $q$-series Author: Junnosuke Koizumi, Anju Yokoi arXiv: http://arxiv.org/abs/2608.26918v1 Title: Efficient Quantum Simulations of Yang-Mills theory with Maximal-tree Gauge Author: Tianyin Li, Ying-Ying Li, Xiaoyang Wang, Hongxi Xing arXiv: http://arxiv.org/abs/2608.27267v1 Title: Krylov Break Times from an Inhomogeneous Lieb--Robinson Light Cone Author: Shunji Matsuura, Yoji Kawamura, Joseph Salfi, Satoshi Iso arXiv: http://arxiv.org/abs/2608.27399v1 Title: Low-Frequency Gravitational Bremsstrahlung and Memory in a Medium Author: Diego Blas, Silvia Gasparotto, Hitoshi Murayama, Jan Schütte-Engel, Jann Zosso arXiv: http://arxiv.org/abs/2608.24994v1
-
2026-09-01
Hot Topic
From Vietnam to Korea: A Summer of Quantum Computing
Duc-Truyen Le, a graduate student at Saitama University, is currently affiliated with iTHEMS as an International Program Associate (IPA). This summer, he participated in a series of quantum computing activities in Vietnam and Korea. In Vietnam, his team received an Honorable Mention at an international quantum computing hackathon involving participants from across Southeast Asia. We asked Duc-Truyen to share his experience with the iTHEMS community: From July 9 to 31, I stayed in Vietnam, mainly to prepare for and participate in a major quantum computing event that brought together scientists, industry leaders, policymakers, and government representatives. The event aimed to strengthen collaboration and promote investment in quantum technologies across both the public and private sectors. The program consisted of a series of activities held over more than a week, including workshops, discussions, networking events, and competitions. One of the highlights was the International Hackathon on Quantum Computing for Social Good (QC4SG Vietnam 2026 / 2nd SEA Quantathon), which brought together participants from across Southeast Asia. The competition was highly selective, with more than 500 initial applications. Selected teams went through a training phase before the finalists were invited to Vietnam to present their projects. For more information about the competition, please see the related link below. Among more than 20 finalist teams, comprising around 100 participants, our team, QuanWatt, was honored to receive an Honorable Mention. It was a rewarding experience and a valuable opportunity to exchange ideas with participants from different backgrounds. Our project explored how quantum computing could contribute to the analysis of modern power systems, which are becoming increasingly complex with the growing integration of renewable energy sources and smart-grid technologies. Although considerable work remains before such approaches can be applied in practice, it was encouraging to see increasing interest from both academia and industry in practical applications of quantum computing. Following the program in Vietnam, I traveled to Korea, where I attended a course at the Institute for Basic Science (IBS) from August 1 to 8 on “Quantum Computing for Quantum Field Theory.” This provided another valuable opportunity to learn about the rapidly developing connections between quantum computing and fundamental physics. Overall, these experiences in Vietnam and Korea were both memorable and intellectually stimulating. I am very grateful for the opportunity to participate and for the continued support I have received from iTHEMS.
-
2026-08-31
Hot Topic
The 3rd NCTS-iTHEMS Joint Workshop on Theoretical, Mathematical, and Computational Sciences on August 18, 2026
The 3rd NCTS-iTHEMS Joint Workshop on Theoretical, Mathematical, and Computational Sciences was held from August 18 to 21, 2026, at the NCTS Physics Lecture Hall in the Cosmology Hall of National Taiwan University (NTU), Taipei. This was the third workshop in the series jointly organized by Taiwan's National Center for Theoretical Sciences (NCTS) and RIKEN iTHEMS, following the first workshop hosted by NCTS in 2024 and the second hosted by RIKEN in 2025. This year's workshop carried special significance as the first major joint activity after the signing ceremony held at NTU on April 23, 2026, where iTHEMS and NCTS launched the joint research initiative "Mathematical Frontiers for Matter, Life, and the Universe." The initiative, signed by iTHEMS Director Satoshi Iso and NCTS Directors Pei-Ming Ho and Ming-Lun Hsieh, aims to foster outstanding early-career researchers and to promote researcher exchanges, international symposia, and collaborative research between the two institutions. Reflecting this spirit, the scope of the workshop expanded beyond previous editions to encompass theoretical physics, mathematics, and computational sciences. The four-day program featured 28 talks and 10 posters. Three plenary lectures were delivered by Tzu-Chieh Wei (Stony Brook University) on the stability of quantum many-body phases against time-dependent perturbations, Etera Livine (ENS Lyon) on spinfoam approaches to quantum gravity, and Tan Bui-Thanh (UT Austin) on model-constrained scientific machine learning for digital twins. Thirteen invited speakers from RIKEN iTHEMS and twelve from Taiwanese universities and Academia Sinica presented research spanning high-energy physics, gravity, condensed matter physics, quantum information and computing, geometry and topology, applied mathematics, machine learning, and scientific AI. In the poster session, ten presenters, mostly students and early-career researchers, introduced their work in three-minute flash talks followed by lively discussions over coffee. The directors of both institutions delivered the opening and closing remarks, and the iTHEMS and NCTS organizers held internal discussions on future joint activities during the workshop. The interdisciplinary atmosphere led to many cross-field conversations during the coffee breaks, the poster session, and the banquet, and several new contacts between researchers of the two institutions were established. We thank the NCTS staff for their excellent local organization and all speakers and participants for making the workshop a success. We look forward to continuing the series and to deepening the collaboration between NCTS and iTHEMS under the new initiative. Reported by Ching-Kai Chiu
-
2026-08-27
Paper of the WeekWeek 5, August 2026
Title: Non-perturbative news from the conformal window Author: Álvaro Pastor-Gutiérrez arXiv: http://arxiv.org/abs/2608.23674v1 Title: Borell--Brascamp--Lieb inequality with finitely many output functions Author: Takashi Satomi arXiv: http://arxiv.org/abs/2608.23963v1 Title: Sexual conflict and sexual pleiotropy Author: Thomas J. Hitchcock, Andy Gardner, Tracey Chapman, Jennifer C. Perry Journal Reference: Proc. R. Soc. B (2026) 293 (2077): 20253103 . doi: https://doi.org/10.1098/rspb.2025.3103 Title: Hilbert space relation from dS to AdS through Reflection Positivity Author: Yu-ki Suzuki arXiv: http://arxiv.org/abs/2608.19948v1
-
2026-08-25
Press Release
New Mechanism for Sustaining Reputation-Based Cooperation Revealed
An international research team including iTHEMS Team Director Yohsuke Murase has theoretically uncovered a new mechanism that enables the evolution of reputation-based cooperation. In human societies, “indirect reciprocity,” in which people decide whether to cooperate with others based on their reputations, is considered an important mechanism for sustaining cooperation. However, previous studies have shown that maintaining cooperation becomes difficult when individuals hold different assessments of the same person. In this study, the researchers introduced a mechanism called “dual reputation updating,” in which reputations are updated based not only on whether a person cooperates with others, but also on whether that person receives cooperation from others. Through mathematical analysis and computer simulations, they demonstrated that this simple extension reduces disagreements in reputation and substantially enhances the maintenance of cooperation. These findings are expected to deepen our understanding of how cooperation emerges and is sustained through reputation, while also providing new insights into collective behaviors in real-world societies, including conformity, cooperation, and exclusion. The findings are scheduled to be published in the Proceedings of the National Academy of Sciences (PNAS) on August 28, 2026.
-
2026-08-25
Award
Keiya Hirashima receives the High-Resolution Award at the 13th IRMAIL Science Grant
Keiya Hirashima (Special Postdoctoral Researcher, iTHEMS) received the High-Resolution Award at the FY2026 13th IRMAIL Science Grant organized by Strategic, Inc. His selected research project is titled “High-resolution simulation of the Milky Way galaxy using AI surrogate models.” The project aims to combine AI with high-performance GPUs to simulate the Milky Way at a resolution capable of representing individual stars. Congratulations, Keiya!
-
2026-08-20
Paper of the WeekWeek 4, August 2026
Title: A Rotor-Dressed Semiton State in a Monopole--Fermion Model Author: Yuta Hamada arXiv: http://arxiv.org/abs/2608.18345v1 Title: Anomaly-Induced Phenomena with Massive Fermions: Higher-Landau-Level Dominance from Spatially Modulated Electric Fields Author: Koichi Hattori, Kazuya Mameda, Takeru Uchiyama, Di-Lun Yang arXiv: http://arxiv.org/abs/2608.17611v1 Title: Matrix product operator representations for the local conserved quantities of the spin-$1/2$ XYZ chain Author: Kohei Fukai, Kyoichi Yamada arXiv: http://arxiv.org/abs/2601.09245v2 Title: Riesz--Laurent representation of black-hole scattering and sourced response at exceptional points Author: Okuto Morikawa, Shoya Ogawa, Takuya Hirose arXiv: http://arxiv.org/abs/2608.14752v1 Title: Deformation of scalar generalized bi-Hamiltonian structure Author: Zhe Wang arXiv: http://arxiv.org/abs/2608.15538v1 Title: Axion Isocurvature Perturbations Survive the Scaling Evolution of Axion Domain Walls Author: Naoya Kitajima, Junseok Lee, Kai Murai, Fuminobu Takahashi, Wen Yin arXiv: http://arxiv.org/abs/2608.13650v1 Title: Parent–offspring conflict over sex determination in non-Mendelian systems Author: Thomas J. Hitchcock, Robert B. Baird Journal Reference: Evolution, qpag098 (2026) doi: https://doi.org/10.1093/evolut/qpag098 Title: Non-perturbative quark production and transport in the evolving glasma: the WAGASHI event generator Author: Nicholas J. Benoit, Chiho Nonaka, Hidetoshi Taya arXiv: http://arxiv.org/abs/2608.13393v1
-
2026-08-20
Person of the Week
Self-introduction: Abdul Raafik Arattu Thodika
Hi, I work on molecular simulations of protein systems. I completed my Ph.D. at the University of Texas at Arlington in 2026. My research uses multiscale quantum mechanical/molecular mechanical (QM/MM) simulations to understand the thermodynamics and kinetics of chemical reactions in enzymes. A major part of my work involves integrating machine learning with these simulations to make them faster and more accurate.
-
2026-08-17
Hot Topic
Farewell message from Sungsik Kong
Our colleague, Sungsik Kong, will be joining Sejong University in South Korea as a tenure-track Assistant Professor in September 2026. We will all miss him and wish him every success in this exciting new chapter. Here is a message from Sungsik: I joined iTHEMS in August 2025, and over the past year I have had the privilege of working in an exceptional research environment. Starting in September 2026, I will be joining Sejong University in South Korea as a tenure-track Assistant Professor. While I am excited about this move, I am also sad to be leaving my position as a Research Scientist at iTHEMS. My time at RIKEN has been both challenging and incredibly rewarding. I am deeply grateful to RIKEN and iTHEMS for giving me the opportunity to pursue the scientific questions I am passionate about. I will miss iTHEMS' collaborative atmosphere. I have had the chance to learn from researchers across many different fields, many that I would never have had the opportunity to explore otherwise. Those seminars, colloquiums, and conversations have broadened my perspective, sparked new ideas, and made my time here truly valuable and memorable. If you ever visit Seoul, please don't hesitate to get in touch. Thank you all so much. It has been a real pleasure.
-
2026-08-13
Paper of the WeekWeek 3, August 2026
Title: Sectoral inter-dependencies drive the loss of structural balance in signed financial networks Author: Kartik Dahake, Abhijit Chakraborty arXiv: http://arxiv.org/abs/2608.12023v1 Title: Imprints of core/cusp dark matter distributions on black hole signatures in galaxies Author: Hassan Hassanabadi, Che-Yu Chen, Soroush Zare, Volker Perlick arXiv: http://arxiv.org/abs/2608.11430v1 Title: Black hole spectroscopy: from theory to experiment Author: Emanuele Berti, Vitor Cardoso, Gregorio Carullo, Jahed Abedi, Niayesh Afshordi, Simone Albanesi, Vishal Baibhav, Swetha Bhagwat, José Luis Blázquez-Salcedo, Béatrice Bonga, Bruno Bucciotti, Giada Caneva Santoro, Pablo A. Cano, Collin Capano, Mark Ho-Yeuk Cheung, Cecilia Chirenti, Gregory B. Cook, Adrian Ka-Wai Chung, Marina De Amicis, Kyriakos Destounis, Oscar J. C. Dias, Walter Del Pozzo, Francisco Duque, Will M. Farr, Eliot Finch, Nicola Franchini, Kwinten Fransen, Vasco Gennari, Stephen R. Green, Scott A. Hughes, Maximiliano Isi, Xisco Jimenez Forteza, Gaurav Khanna, Fech Scen Khoo, Masashi Kimura, Badri Krishnan, Adrien Kuntz, Macarena Lagos, Rico K. L. Lo, Lionel London, Sizheng Ma, Simon Maenaut, Lorena Magaña Zertuche, Elisa Maggio, Andrea Maselli, Keefe Mitman, Hayato Motohashi, Naritaka Oshita, Costantino Pacilio, Paolo Pani, Rodrigo Panosso Macedo, Chantal Pitte, Lorenzo Pompili, Jaime Redondo-Yuste, Maurício Richartz, Antonio Riotto, Jorge E. Santos, Bangalore Sathyaprakash, Laura Sberna, Hector O. Silva, Leo C. Stein, Alexandre Toubiana, Sebastian H. Völkel, Julian Westerweck, Huan Yang, Sophia Yi, Nicolas Yunes, Hengrui Zhu Journal Reference: Class. Quantum Grav. 43 (2026) 123001 doi: https://doi.org/10.1088/1361-6382/ae59e2 arXiv: http://arxiv.org/abs/2505.23895v3 Title: A MUSE View of the Optical Torus within the Supernova Remnant 1E 0102.2-7219 Author: Janette Suherli, Samar Safi-Harb, Ivo R. Seitenzahl, Frédéric P. A. Vogt, Parviz Ghavamian, Ralph Sutherland, Chuan-Jui Li, Ashley J. Ruiter, Gilles Ferrand doi: https://doi.org/10.3847/1538-4357/ae7d1e arXiv: http://arxiv.org/abs/2606.17563v1 Title: Revisiting the Supernova Engines in the 3C 397 and W49B Supernova Remnants Author: Cole Treyturik, Chelsea Braun, Samar Safi-Harb, Christopher L. Fryer, Gilles Ferrand arXiv: http://arxiv.org/abs/2512.01176v1 Title: A Systematic Study of Type Ia Supernova Remnants: Using Nucleosynthesis to Probe their Supernova Progenitors Author: Cole Treyturik, Samar Safi-Harb, Gilles Ferrand arXiv: http://arxiv.org/abs/2608.07778v1 Title: Magnetic Catalysis and Fermion Mass Generation in de Sitter Spacetime Author: Kohei Fujikura, Toshifumi Noumi, Shintetsu Yamazaki arXiv: http://arxiv.org/abs/2608.07270v1 Title: Involutive Khovanov homology and equivariant knots II Author: Taketo Sano arXiv: http://arxiv.org/abs/2608.07114v1
-
2026-08-07
Featured Paper of the Week
Using chaos and symmetry to bootstrap quantum gravitational wormholes
An international research collaboration between Gabriele Di Ubaldo (RIKEN-Berkeley Center at UC Berkeley and RIKEN iTHEMS), Jan Boruch (University of California, Berkeley, US), Felix M. Haehl (University of Southampton, UK), Eric Perlmutter (Université Paris-Saclay and Institut des Hautes Études Scientifiques, France), and Moshe Rozali (University of British Columbia, Canada) published the new study in Physical Review Letters. Random matrix theory provides a universal description of chaos in quantum systems, capturing statistical patterns among energy levels without requiring knowledge of microscopic details. The new challenge addressed is its extension to 2D Conformal Field Theories and their holographically dual 3D quantum gravity via the AdS₃/CFT₂ correspondence. In the AdS₃/CFT₂ correspondence, quantum gravity in a three-dimensional negatively curved spacetime is encoded in a two-dimensional conformal field theory on its boundary. The key difference is modular invariance, a symmetry stating that a theory on a 2D torus is invariant under modular transformations, which imposes stringent constraints and a rigid mathematical structure, seemingly incompatible with quantum chaos and random matrix theory. Building on the 2023 work of Di Ubaldo and Perlmutter, “AdS₃/RMT₂ duality”, the researchers developed a general, nonperturbative framework called RMT₂ that uplifts the correlations of any random matrix model into fully modular-invariant quantities. The team then used RMT₂ to predict quantum amplitudes for 3D wormholes with multiple torus-shaped boundaries. A wormhole is a tunnel-like geometric connection between otherwise separate regions or boundaries of spacetime. While it is not a shortcut for interstellar travel as in sci-fi movies, it encodes deeply quantum information about gravity and black holes. For the three-boundary wormhole, the team also performed a gravity calculation that agrees with the RMT₂ prediction. By turning the earlier AdS₃/RMT₂ proposal into a general framework, the study advances a research direction that Gabriele helped pioneer and provides a new tool for probing black-hole microstates and, in the near future, solving AdS₃ quantum gravity. For further details, please see the article in Physical Review Letters.
-
2026-08-07
Award
Riccardo Muolo Awarded Third Place at Falling Walls Lab Tokyo 2026
Riccardo Muolo awarded 3rd Place at Falling Walls Lab Tokyo, Japan Riccardo Muolo (Special Postdoctoral Researcher, Division of Fundamental Mathematical Science, iTHEMS) took part in the Falling Walls Lab Tokyo, Japan, held on 28 July 2026 at Shibuya Sakura Stage, and was awarded 3rd Place by the jury. The Falling Walls Lab is an international pitch and science-communication competition hosted by the Falling Walls Foundation, a Berlin-based non-profit founded in 2009 on the twentieth anniversary of the fall of the Berlin Wall. The Foundation channels the spirit of that night to ask a recurring question — which are the next walls to fall in science and society — and works to make breakthrough ideas accessible across borders and disciplines. Open to students and early-career professionals of all disciplines and nationalities, the Lab invites participants to pitch their research, business model, or innovative idea in just three minutes, in front of their peers and a jury from academia and business. Academic institutions around the world are invited to host their own Falling Walls Lab and send their winners to the Falling Walls Lab Finale in Berlin, where the Finalists compete for the title of Breakthrough Winner in the Emerging Talents category and the chance to pitch again on the main stage of the Falling Walls Science Summit. This year’s Tokyo edition was organized by EURAXESS Japan, the German Centre for Research and Innovation (DWIH) Tokyo, and Tobitate! Japan. Riccardo’s research covers nonlinear dynamics on networks and higher-order structures, synchronization, Turing pattern formation, and the control of dynamical systems — exactly the kind of cross-disciplinary work the Falling Walls Lab is designed to showcase. Distilling it into a compelling three-minute pitch and earning recognition among a strong international field of participants is a fine achievement. Congratulations, Riccardo!
-
2026-08-06
Press Release
Discovery of Anomalous Fluctuations and Universality in Atom Detection Counts
Kazuki Yamamoto, Lecturer at the Graduate School of Science, Osaka Metropolitan University, and Ryusuke Hamazaki, RIKEN Hakubi Research Team Leader at the RIKEN Pioneering Research Institute and Senior Research Scientist at the RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS), have theoretically demonstrated that the fluctuations in the number of detected atoms in a continuously measured quantum many-body system consisting of a large number of atoms change dramatically depending on the measurement strength. They found that when the measurement is weak, the number of detected atoms exhibits standard fluctuations, whereas when the measurement is strong, unusually large anomalous fluctuations emerge. For more details, please visit the Osaka Metropolitan University website.
-
2026-08-06
Paper of the WeekWeek 2, August 2026
Title: Machine-Learning Search for Lax Connections Author: Osamu Fukushima, Tomohiro Shigemura, Ryosuke Suda, Norihiro Tanahashi, Kentaroh Yoshida arXiv: http://arxiv.org/abs/2608.05146v1 Title: Dualizable Additive Categories Author: Ishan Levy, Jiacheng Liang, Vladimir Sosnilo arXiv: http://arxiv.org/abs/2608.04898v1 Title: Primordial Correlators from a Kaluza-Klein Graviton Continuum Author: Shuntaro Aoki arXiv: http://arxiv.org/abs/2608.01762v1 Title: The $g$-mode frequencies in cold neutron stars and nuclear saturation parameters Author: Hajime Sotani, Hajime Togashi arXiv: http://arxiv.org/abs/2608.02463v1 Title: Excitation region of Kerr black hole quasinormal modes from Stokes geometry Author: Naritaka Oshita arXiv: http://arxiv.org/abs/2607.28930v1 Title: Cooling of Hybrid Stars with a 2SC+$
- $ Phase Author: Tsuneo Noda, Akira Dohi, Nobutoshi Yasutake, Huan Chen, Toshiki Maruyama, Toshitaka Tatsumi arXiv: http://arxiv.org/abs/2606.31389v2
-
2026-07-30
Paper of the WeekWeek 5, July 2026
Title: $\mathrm{SL}(2,\mathbb{Z})$ Theta Subgroup Structure of Maxwell theory in the Lattice Villain Hamiltonian Formulation Author: Shoto Aoki, Yoshio Kikukawa, Toshinari Takemoto arXiv: http://arxiv.org/abs/2607.25332v1 Title: A Path Integral Model of Cognition Author: Haruki Emori, Kazunori Kondo, Atsushi Iriki, Andrei Khrennikov arXiv: http://arxiv.org/abs/2607.24807v1 Title: Universality of dual mass-scaled fundamental modes in two-fluid neutron stars with mirror dark matter Author: Hajime Sotani, Ankit Kumar arXiv: http://arxiv.org/abs/2607.27005v1 Title: Expected number density of critical points of smooth Gaussian random fields in arbitrary dimensions Author: Satoshi Kuriki, Takahiko Matsubara, Satoshi Iso arXiv: http://arxiv.org/abs/2607.23903v1 Title: Page transition for the complexity of an evaporating black hole Author: Violet Concepcion, Yasunori Nomura, Kyle Ritchie, Samuel Weiss arXiv: http://arxiv.org/abs/2607.21734v1 Title: Continuous solutions of the complex Kac--Bernstein functional equation on the integers and the real numbers Author: Takashi Satomi arXiv: http://arxiv.org/abs/2607.24033v1 Title: On the Nucleon Effective Mass in Neutron Stars Cooling Author: Yuuki Sugiyama, Akira Dohi arXiv: http://arxiv.org/abs/2607.23253v1 Title: A lower bound on primordial power spectrum from halo substructure Author: Shin'ichiro Ando, Nagisa Hiroshima, Koji Ishiwata, Tomo Takahashi arXiv: http://arxiv.org/abs/2607.20884v1 Title: Stochastic Quantization as Optimal Control Author: Lingxiao Wang arXiv: http://arxiv.org/abs/2607.21436v1 Title: Unitary $k$-designs without Hamiltonian quenches Author: Pratik Nandy arXiv: http://arxiv.org/abs/2607.20640v1
-
2026-07-29
Hot Topic
2026 iTHEMS Visit by the National Sun Yat-sen University, Taiwan
On June 25, a group of 3 professors and 13 students from National Sun Yat-sen University, Taiwan, visited RIKEN . The purpose of the visit was to immerse the students in RIKEN’s multidisciplinary research environment and introduce them to stateoftheart scientific methodologies. It also aimed to inspire their future research careers while exploring opportunities for academic exchange and longterm collaboration between both institutions. First, the group visited RIKEN Nishina Center for Accelerator-Based Science, hosted by Dr Claudio Santonastaso & Dr Seiya Sakai. Next visit was RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS), hosted by Dr. Gen Kurosawa. Last visit was RIKEN Center for Quantum Computing, hosted by Dr. Franco Nori. Gen Kurosawa, Senior Research Scientist, introduced iTHEMS’s interdisciplinary research environment and explained how mathematical methods from physics can be applied to important questions in biological clocks, leading to testable predictions that are verified experimentally.
-
2026-07-24
Hot Topic
Farewell message from Puttarak Jai-akson
Our colleague, Puttarak Jai-akson, will be joining the Graduate School of Science, Kyoto University, as a Program-Specific Researcher, starting in August 2026. We will all miss him and wish him every success in this exciting new chapter. Here is a message from Puttarak: I would like to share that I will be leaving my position as a Postdoctoral Researcher at iTHEMS. I joined iTHEMS in November 2022, and after nearly four wonderful years, I will be moving to a new position as a Researcher at Kyoto University, starting in August 2026. During my time at iTHEMS, I greatly enjoyed the open, friendly, and interdisciplinary research environment. The opportunity to interact with researchers from diverse fields has broadened my perspective, inspired many new ideas, and significantly enriched my research. I am deeply grateful to all the members of iTHEMS for their support, encouragement, and the many enjoyable discussions we have shared. I would also like to express my heartfelt thanks to our wonderful iTHEMS Assistants, whose kindness, professionalism, and constant support made my time at iTHEMS all the more enjoyable. Although I am leaving my full-time position, I am pleased to continue my affiliation with iTHEMS as a Visiting Scientist. I sincerely hope to continue our discussions and collaborations in the future. If you happen to visit Kyoto University, please don't hesitate to let me know. I would be very happy to catch up and continue our conversations. Thank you all very much for everything. It has been a privilege to be part of iTHEMS, and I wish everyone continued success.
-
2026-07-23
Paper of the WeekWeek 4, July 2026
Title: Interacting Dark Energy and Dark Matter in O(3) No-Scale Gravity Author: Lincoln da S. Pereira, Muzi Hong, Elisa G. M. Ferreira, Tsutomu T. Yanagida arXiv: http://arxiv.org/abs/2607.20320v1 Title: Gravitational waves from self-resonance during reheating with a quantum-corrected inflaton potential Author: Tomoya Inada, Noel Jonathan Jobu, Kenji Nishiwaki, Toshifumi Noumi, Naoki Yamatsu arXiv: http://arxiv.org/abs/2607.18381v1
-
2026-07-16
Paper of the WeekWeek 3, July 2026
Title: Isometries between C$^*$-algebras with finite corank Author: Michiya Mori arXiv: http://arxiv.org/abs/2607.13367v1 Title: Strong-to-Weak Spontaneous Symmetry Breaking from Wormholes in Holography Author: Taishi Kawamoto, Kenya Tasuki, Masahito Yamazaki arXiv: http://arxiv.org/abs/2607.12022v1 Title: Evading Cosmological Strong Coupling in Non-minimally Coupled Vector Gravity Author: Antonio De Felice, Seishi Enomoto, Nagisa Hiroshima, Atsushi Naruko arXiv: http://arxiv.org/abs/2607.11125v1 Title: Magnitude homology of tope graphs Author: Junnosuke Koizumi arXiv: http://arxiv.org/abs/2607.11863v1 Title: Catalog of Altermagnetism in Magnetic Wallpaper/Space Groups and Nonsymmorphic Altermagnets Author: Congcong Le, Fan Cui, Iao-Fai Io, Moritz Hirschmann, Xianxin Wu, Ching-Kai Chiu arXiv: http://arxiv.org/abs/2607.10857v1 Title: Quantum Logic as the Logic of Contexts Author: Haruki Emori, Atsushi Iriki, Andrei Khrennikov, Kazunori Kondo arXiv: http://arxiv.org/abs/2607.09032v1 Title: Solving models with generalized free fermions I: Algebras and eigenstates Author: Kohei Fukai, Balázs Pozsgay, István Vona arXiv: http://arxiv.org/abs/2602.03431v1 Title: A free fermions in disguise model with claws Author: Kohei Fukai, István Vona, Balázs Pozsgay Journal Reference: SciPost Phys. 21, 011 (2026) doi: https://doi.org/10.21468/SciPostPhys.21.1.011 arXiv: http://arxiv.org/abs/2508.05789v2 Title: Diffusion Models for Sampling Near Criticality in Lattice Field Theories Author: Yang-yang Tan, Gert Aarts, Diaa E. Habibi, Biagio Lucini, Lingxiao Wang arXiv: http://arxiv.org/abs/2607.08505v1 Title: Nuclear Many-Body Systems as Benchmarks for Quantum Computing Author: Sota Yoshida, Alessandro Baroni, Takayuki Miyagi, Ermal Rrapaj arXiv: http://arxiv.org/abs/2607.08047v1
-
2026-07-16
Hot Topic
2026 iTHEMS Visit by the University of California San Diego Global Seminar Program
On July 8, Dr. Stanley Lo, Teaching Professor in the Department of Cell and Developmental Biology at the School of Biological Sciences, UCSD, visited iTHEMS together with 24 undergraduate students. The purpose of the visit was to learn about iTHEMS and its research activities while supporting the students’ learning about human diversity and the relationship between science and society. Thomas Hitchcock, Research Scientist at iTHEMS, hosted the lecture. He introduced his academic and professional background and presented his current research on evolution, ecology, and genetics.
-
2026-07-09
Paper of the WeekWeek 2, July 2026
Title: Strong Evidence for Three-$α$ Clustering in the Ground State of $^{12}\mathrm{C}$ Author: Kazuki Yoshida, Masaaki Kimura arXiv: http://arxiv.org/abs/2606.31437v1 Title: 6d Supergravity Blocks Author: Yuta Hamada, Seongmin Jeon, Hee-Cheol Kim arXiv: http://arxiv.org/abs/2607.05496v1 Title: Equation of state of QCD(-like) theory using Lattice Monte Carlo simulations Author: Etsuko Itou arXiv: http://arxiv.org/abs/2607.04624v1 Title: Quiver BPS Indices from Crystal Profiles Author: Jiakang Bao, Masahito Yamazaki arXiv: http://arxiv.org/abs/2607.03617v1 Title: Lattice study of primordial black hole formation in bumpy axion inflation Author: Masahiro Kawasaki, Kai Murai, Shunsuke Tsuchida arXiv: http://arxiv.org/abs/2607.01780v1
-
2026-07-02
Paper of the WeekWeek 1, July 2026
Title: Three-Dimensional Simulations of Type Ia Supernova Remnants I: Effects of a Main-Sequence Companion Star Author: Jingxiao Luo, Gilles Ferrand, Zhengwei Liu, Xuefei Chen, Zhanwen Han Journal Reference: ApJ, 1005, 117 (2026) doi: https://doi.org/10.3847/1538-4357/ae6ce6 arXiv: http://arxiv.org/abs/2607.00354v1 Title: Rethinking quantum information in gravity and fields Author: Kanato Goto, Yuta Hamada, Kohtaro Kato, Takato Mori, Yoshifumi Nakata, Masataka Watanabe, Hayata Yamasaki, Masahito Yamazaki, Takuya Yoda arXiv: http://arxiv.org/abs/2606.30853v1 Title: Analytic index theory and spectral flow in real Hilbert $C^*$-modules Author: Chris Bourne, Alan L. Carey, Koen van den Dungen, Adam Rennie arXiv: http://arxiv.org/abs/2606.31322v1 Title: FRG analysis of dense two-color QCD within the linear sigma model Author: Gergely Fejős, Daiki Suenaga arXiv: http://arxiv.org/abs/2606.31040v1 Title: Nonequilibrium Andreev transport at the QGP-2SC interface Author: Tingyu Zhang, Honoka Hoshino, Hiroyuki Tajima, Motoi Tachibana, Mariusz Sadzikowski arXiv: http://arxiv.org/abs/2606.30521v1 Title: Characterisation of reactive Nash equilibria in repeated additive games Author: Franziska Lesigang, Christian Hilbe, Nikoleta E. Glynatsi arXiv: http://arxiv.org/abs/2606.27653v1 Title: Simultaneous Estimation of Partial-Transpose Moments with Active Memory Independent of the Moment Order Author: Junxiang Huang, Xiaoyang Wang, Xiao Yuan, Yukun Zhang arXiv: http://arxiv.org/abs/2606.14204v2
-
2026-06-25
Paper of the WeekWeek 4, June 2026
Title: Time-dependent weighted directed networks of cryptocurrency interaction from high-frequency returns Author: Shubhangam Shukla, Mahesh Peyyala, Abhijit Chakraborty arXiv: http://arxiv.org/abs/2606.25466v1 Title: Time-reversal symmetric topological superconductivity in Machida-Shibata lattices Author: Ioannis Ioannidis, Ching-Kai Chiu, Thore Posske arXiv: http://arxiv.org/abs/2504.08674v2 Title: Neutrinoless double $β$ decay and leptogenesis in seesaw model Author: Kazuo Fujikawa arXiv: http://arxiv.org/abs/2606.24109v1 Title: Conformal blocks, parenthesized braid operad, and $c=1/2$ Virasoro vertex operator algebra Author: Yuto Moriwaki arXiv: http://arxiv.org/abs/2606.23076v1 Title: Microscopic mechanism of the Fayans pairing for the enhancement of charge radii Author: Tomoya Naito, Gianluca Colò, Xavier Roca-Maza, Hiroyuki Sagawa, Enrico Vigezzi arXiv: http://arxiv.org/abs/2606.21491v1 Title: Mechanistic mathematical model of the in vitro infection dynamics of Bunyamwera and Batai viruses including MOI-dependent shortening of the eclipse phase Author: Bevelynn Whaler, Eleanor Todd, Amelia B. Shaw, John N. Barr, Catherine A. A. Beauchemin, Grant Lythe, Carmen Molina-Paris, Martin Lopez-Garcia arXiv: http://arxiv.org/abs/2606.21481v1 Title: Quantum Simulation of Generalized Parton Distributions in the Schwinger Model Author: Tianyin Li, Hongxi Xing arXiv: http://arxiv.org/abs/2606.22602v1 Title: Macroscopic Black-Hole Remnants in a Nonlocal Field Theory: Towards Hawking Radiation in SFT Author: Feng-Yin Cheng, Pei-Ming Ho, Wei-Hsiang Shao arXiv: http://arxiv.org/abs/2606.20314v1
-
2026-06-24
Press Release
Tracing the Origin of the “Freely Chosen Numbers” Appearing in the Laws of Nature
An international research team including Yuya Kusuki, Visiting Scientist at iTHEMS (Associate Professor, Institute for Advanced Study, Kyushu University), analyzed a situation in which two conformal field theories are connected through an interface. The researchers showed that, by appropriately extracting the response to a small deformation of the interface, one can obtain a local operator that captures the difference between the two theories. They also provided an explicit method for constructing such operators. This result lends support to the conjecture that quantum gravity does not admit continuous parameters that can be freely chosen from the outside, and is expected to contribute to a deeper understanding of fundamental issues in quantum gravity. For further details, please see the press release from Kyushu University.
-
2026-06-18
Paper of the WeekWeek 3, June 2026
Title: Holographic Schwinger-Keldysh effective action for heavy quarks in confinement and deconfinement phases Author: Shin Nakamura, Daichi Takeda arXiv: http://arxiv.org/abs/2606.17919v1 Title: A Lindbladian for holographic Brownian motion Author: Daichi Takeda arXiv: http://arxiv.org/abs/2606.17909v1 Title: Structural Oscillatority Criterion of Boolean Networks Author: Hiroki Kodama arXiv: http://arxiv.org/abs/2606.15852v1 Title: Non-Archimedean balanced metrics and their application to totally degenerate abelian varieties Author: Keita Goto arXiv: http://arxiv.org/abs/2606.15758v1 Title: Hadronic tensor in lattice gauge theories by quantum computing Author: Dairui Zou, Tianyin Li, Jian Liang, Enke Wang, Hongxi Xing arXiv: http://arxiv.org/abs/2606.17003v1 Title: Hadron spectra of finite-density QC$_2$D Author: Kei Iida, Etsuko Itou, Kotaro Murakami, Daiki Suenaga arXiv: http://arxiv.org/abs/2606.13974v1 Title: Invariants of Sequential Circuits and Generalized Non-Abelian Statistics Author: Shintaro Sato, Yoshimasa Hidaka, Ryohei Kobayashi arXiv: http://arxiv.org/abs/2606.11527v1 Title: Numerical Hints for Dyon Condensation at $θ=2π$ via Wilson-'t Hooft Loops in $SU(2)$ Yang-Mills Theory Author: Hiromasa Watanabe, Issaku Kanamori, Okuto Morikawa, Yuki Nagai, Yuya Tanizaki, Akio Tomiya arXiv: http://arxiv.org/abs/2606.13428v1 Title: A model of local and global reciprocity Author: Mari Kawakatsu, Yohsuke Murase, Taylor A. Kessinger, Joshua B. Plotkin arXiv: http://arxiv.org/abs/2606.13678v2
-
2026-06-11
Paper of the WeekWeek 2, June 2026
Title: Collective neutrino oscillations: Many-body non-forward effects and non-classicality Author: Julien Froustey, Ermal Rrapaj, Yuhao Liu, Gushu Li, Costin Iancu, Vincenzo Cirigliano arXiv: http://arxiv.org/abs/2606.12404v1 Title: Searches for GeV-Scale ALPs at RHIC Author: Kaori Fuyuto, Claudio Andrea Manzari, Hitoshi Murayama arXiv: http://arxiv.org/abs/2606.07739v1 Title: Post-Merger Gravitational-Wave Uncertainties of Binary Neutron Stars under Multi-Messenger EOS Constraints Author: Yong-Jia Huang, Luca Baiotti arXiv: http://arxiv.org/abs/2606.08522v2 Title: Generative Criticality in Large Language Model Temperature Scaling Author: Huajian Ruan, Jinyang Li, Xingyu Guo, Lingxiao Wang arXiv: http://arxiv.org/abs/2606.06238v1 Title: Magnetic Symmetries and the Structure of Correlation Functions in Quantum Field Theory Author: Masaru Hongo, Kentaro Nishimura arXiv: http://arxiv.org/abs/2606.03082v1 Title: Understanding deconfined quantum critical points from crystalline categorical Landau paradigm Author: Hiromi Ebisu, Bo Han, Weiguang Cao arXiv: http://arxiv.org/abs/2606.05856v1 Title: Symmetry-based selection rules for higher-order interactions in coupled oscillators Author: Iván Léon, Riccardo Muolo, Yuanzhao Zhang, Maxime Lucas arXiv: http://arxiv.org/abs/2606.04904v1
-
2026-06-11
Hot Topic
The First RIKEN Quantum International Workshop on Frontiers of Quantum Computing Applications and Quantum-HPC Integration on May 25-26, 2026
The First RIKEN Quantum International Workshop on Frontiers of Quantum Computing Applications and Quantum–HPC Integration was held from May 25 to 26 at the Large Conference Room on the 2nd floor of the Administrative Headquarters, RIKEN Wako Campus. The workshop featured an entirely invited program, consisting of 13 plenary presentations (40 minutes each) and 9 highlight presentations (20 minutes each). The presentations covered a broad range of fields—including quantum chemistry, life sciences, condensed matter physics, atomic physics, and high-energy physics—with a primary focus on the theme of quantum–HPC hybrid integration. With more than 130 registered participants, each presentation was followed by lively and engaging discussions. Furthermore, the networking reception held on the evening of the first day was well-attended, fostering active interaction and collaboration among researchers from universities, national research institutes, and private industries. This workshop is expected to drive further advancements in quantum computing through quantum–HPC hybrid integration. Reported by Shinichiro Fujii
-
2026-06-08
Seminar Report
iTHEMS Math Seminar by Mikhail Khovanov on May 28, 2026
On May 28, 2026, iTHEMS hosted a special iTHEMS Math Seminar, “Introduction to Categorification and Link Homology,” delivered by Professor Mikhail Khovanov of Johns Hopkins University. The event was held in a hybrid format at Okochi Hall and via Zoom, with more than 80 participants attending in person and over 70 joining online. Professor Khovanov is a leading mathematician whose work has had a major influence on knot theory, low-dimensional topology, representation theory, and mathematical physics. He is especially well known for introducing the categorification of the Jones polynomial, now called "Khovanov homology". In the talk, Professor Khovanov introduced the idea of “categorification” by starting from the classical relationship between the Euler characteristic and homology groups in topology. He then discussed the Jones polynomial, a knot invariant introduced by mathematician V. F. Jones in the 1980s, with particular emphasis on its representation-theoretic interpretation. He explained how this invariant can be lifted to a homology theory, guiding the audience toward the construction of Khovanov homology. He concluded the talk by mentioning future directions of the theory, including its connections to algebraic geometry and geometric representation theory. Reported by Taketo Sano
-
2026-06-04
Paper of the WeekWeek 1, June 2026
Title: Noise spectroscopy of two-body loss as a probe of dynamical bulk viscosity in ultracold atomic gases Author: Tingyu Zhang, Hiroyuki Tajima, Takeo Kato arXiv: http://arxiv.org/abs/2606.01835v1 Title: Equivalence of additive and parametric pinning control protocols for systems of weakly coupled oscillators Author: Riccardo Muolo, Yuzuru Kato Journal Reference: 2026 SICE International Symposium on Control Systems (SICE ISCS) doi: https://doi.org/10.23919/SICEISCS67856.2026.11524551 Title: Solving models with generalized free fermions II: Path-product expansion and conserved charges Author: Kohei Fukai, Balázs Pozsgay, István Vona arXiv: http://arxiv.org/abs/2605.31453v1
-
2026-06-03
Award
Keiya Hirashima Receives the HPCI Software Award (Development Division Excellence Award)
Keiya Hirashima, Special Postdoctoral Researcher at the RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS), has received the Excellence Award in the Development Division of the HPCI Software Award, presented by the HPCI Consortium. The HPCI Software Award recognizes young researchers and organizations that have made significant contributions to the advancement of computational science through the development and dissemination of useful software. The Development Division specifically honors software that has demonstrated outstanding value in large-scale computational science and related fields. Hirashima received the award for the development of ASURA-FDPS-ML, a galaxy simulation code that incorporates artificial intelligence technologies. The software combines numerical simulations of galaxy formation and evolution with machine learning techniques, aiming to improve the efficiency and capability of large-scale astrophysical simulations. This award recognizes the significance of integrating computational science and AI technologies to advance next-generation scientific computing. Congratulations, Keiya!
-
2026-06-03
Award
Okuto Morikawa Receives the 21st Particle Physics Medal: Young Scientist Award
Okuto Morikawa, Special Postdoctoral Researcher at the RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS), has been awarded the 21st Particle Physics Medal: Young Scientist Award (FY2026). This award is presented to young researchers who have made outstanding contributions to the field of theoretical particle physics. The award-winning paper established a unified framework based on the exact WKB method for analyzing resonant states, which play an important role in quantum mechanics and quantum field theory. By connecting several previously independent approaches, including Zel'dovich regularization, the complex-scaling method, and the rigged Hilbert space formulation, the work provides a unified perspective on the description of resonant states. The study further demonstrated the effectiveness of this framework through exactly solvable models and was highly recognized for offering new insights that bridge scattering theory, non-Hermitian quantum systems, and resurgence theory. This research advances the fundamental understanding of quantum theories involving resonant states and is expected to contribute to future studies of non-perturbative structures in more general quantum systems, quantum field theories, and quantum gravity. Congratulations, Okuto!
-
2026-06-02
Press Release
Development and Safety Validation of a High-Performance Japanese Medical LLM
As part of NEDO’s project “Safety Verification and Demonstration for the Social Implementation of a Japanese Medical Domain-Specific LLM,” a collaborative research team comprising ten institutions, including the University of Tokyo, RIKEN, and Kyushu University, developed a high-performance Japanese large language model (LLM) designed to support administrative tasks in healthcare settings. In evaluations based on specialist medical examinations, the model achieved an accuracy of up to 90.8%, demonstrating performance comparable to state-of-the-art commercial LLMs. The project also conducted extensive safety assessments tailored to the characteristics of the Japanese healthcare system. Jun Seita, Team Director of the Medical Science Deep Learning Team at iTHEMS, also participated in the project and contributed to its research and development. For more details, please see the NEDO press release.
-
2026-05-28
Paper of the WeekWeek 5, May 2026
Title: Revisiting boundary electromagnetic duality and edge modes Author: Keito Shimizu, Sotaro Sugishita arXiv: http://arxiv.org/abs/2605.27870v1 Title: Estimation of potential radius based on momentum distribution of a constituent particle Author: Eisuke Kawamura, Kotaro Murakami, Daisuke Jido arXiv: http://arxiv.org/abs/2605.28323v1 Title: Fermionic Bubble Loop in Cosmological Collider Revisited: Exact signals from spectral and Mellin-Barnes methods Author: Shuntaro Aoki, Zhehan Qin, Masahide Yamaguchi, Yuhang Zhu arXiv: http://arxiv.org/abs/2605.28054v1 Title: Thom polynomials relative to prescribed maps around the boundary Author: Masato Tanabe arXiv: http://arxiv.org/abs/2603.15010v2 Title: A Casimir obstruction to asymptotically flat black-brane completions of non-supersymmetric 7-branes Author: Yuta Hamada, Hayate Kimura arXiv: http://arxiv.org/abs/2605.25588v1 Title: Beyond Local Detailed Balance: Microscopic Rates Reshape Nonequilibrium Phase Behavior Author: Takahiro Kanazawa, Kyogo Kawaguchi, Kyosuke Adachi arXiv: http://arxiv.org/abs/2605.25406v1 Title: The Pseudospectral Method for the Dirac Equation with Confining Potential Author: Dengshan Liu, Huihui Xie, Pengxiang Du, Jian Li, Tomoya Naito arXiv: http://arxiv.org/abs/2605.25390v1 Title: Thermal Spin Polarization Driven by Nuclear Spin-Orbit Coupling in Neutron Star Pasta Author: Hiroyuki Tajima, Yuta Sekino, Hiroshi Funaki, Shota Kisaka, Nobutoshi Yasutake, Mamoru Matsuo arXiv: http://arxiv.org/abs/2605.25067v1 Title: Dense $\mathrm{QC_2D_2}$ with uniform matrix product states Author: Kohei Fujikura, Yoshimasa Hidaka arXiv: http://arxiv.org/abs/2605.17183v1 Title: Detectability of avoided crossings in black hole ringdowns Author: Hayato Imafuku, Naritaka Oshita, Hiroki Takeda arXiv: http://arxiv.org/abs/2605.16199v1 Title: Spin Hall effect and Berry curvature of gravitons from quantum field theory Author: Ritsuki Ito, Kazuya Mameda, Naoki Yamamoto arXiv: http://arxiv.org/abs/2605.19817v1 Title: Multiwavelength Probes of Cosmic Ray Transport in Molecular Cloud Structures Author: Hayden P. H. Ng, Ellis R. Owen, Naomi Tsuji, Szu-Ting Chen arXiv: http://arxiv.org/abs/2605.16698v1 Title: Multicellular simulations with shape and volume constraints using optimal transport Author: Antoine Diez, Jean Feydy arXiv: http://arxiv.org/abs/2402.17086v4 Title: Editorial Trajectories in Wikipedia Reflect Underlying Hyperlink Structure Author: Yeonji Seo, Mi Jin Lee, Seung-Woo Son, Hang-Hyun Jo, Yohsuke Murase arXiv: http://arxiv.org/abs/2605.16850v1
-
2026-05-26
Press ReleaseIdentifying Topological Superconductors from Fermi Surface Information
An international research group including Seishiro Ono, Special Postdoctoral Researcher, Division of Fundamental Mathematical Science, iTHEMS (at the time of the research; currently Visiting Scientist, Division of Global Collaborations and Research Talent Development), has established a theoretical formula that determines the topological properties of superconductors from information on the “Fermi surface,” which describes the electronic states responsible for electrical conduction and superconductivity. These research results are expected to provide a foundation for efficiently searching for topological superconductors among a vast number of materials, thereby accelerating both theoretical predictions and experimental exploration of candidate materials. For more details, please see the RIKEN press release.
-
2026-05-25
Press Release
Discovery of a New Phenomenon Where Translational Symmetry Can No Longer Be Restored
A research group consisting of Tsubasa Oishi and doctoral student Takuma Saito of the Yukawa Institute for Theoretical Physics, Kyoto University, and Hiromi Ebisu, Research Scientist at RIKEN, has revealed that in systems of arbitrary dimensions subject to the Lieb–Schultz–Mattis (LSM) constraint arising from the interplay between internal symmetry and translational symmetry, the operation known as gauging—which converts a global symmetry into a local one—causes the translational symmetry itself to transform into a non-invertible symmetry. For further details, please see the Kyoto University press release.
-
2026-05-21
Paper of the WeekWeek 4, May 2026
Title: Black-hole formation and thermalization in open JT gravity Author: Ryo Adachi, Rumi Hasegawa, Takanori Ishii, Daichi Takeda arXiv: http://arxiv.org/abs/2605.14573v1 Title: Simulation of vibrational dynamics using qubits and qudits Author: Erik Lötstedt, Kaoru Yamanouchi arXiv: http://arxiv.org/abs/2605.12866v1
-
2026-05-18
Hot Topic
Mayor Takeshi Sakamoto of Itabashi City Visits iTHEMS on May 14
On May 14, Takeshi Sakamoto, Mayor of Itabashi City, visited iTHEMS and met with Center Director Satoshi Iso. Mayor Sakamoto introduced Itabashi City’s initiatives and basic development plan, followed by Director Iso’s presentation on the vision and activities of iTHEMS. The mayor then toured the iTHEMS spaces on the 2nd to 4th floors of the east side of the Main Research Building, where he interacted with researchers engaged in active discussions. In addition, at the Memorial Archives Room, Mayor Sakamoto viewed valuable historical materials that are also connected to Itabashi City.
-
2026-05-18
Hot Topic
Talk Event “Useless Science and Art vol.2” Held at the Museum of Contemporary Art Tokyo
As a related event to the exhibition MOT Collection: Mission∞Infinity – Space × Art × Quantum, currently being held at the Museum of Contemporary Art Tokyo, the talk event “Useless Science and Art vol.2: Prototyping ‘Useless’ Science and Art” took place on Wednesday, May 6, 2026. This event was organized in connection with Black Hole Recorder, a work inspired by quantum black hole theory. Researchers and creators gathered to discuss the new possibilities that can emerge from ideas that may initially appear “useless.” Approximately 110 people attended the event. During the talks, the speakers introduced the conceptual framework of Black Hole Recorder and the theoretical ideas behind its creation. Visitors were also able to experience part of the work through a listening session held at the venue. The speakers included Tetsuo Hatsuda (Team Director, Quantum Mathematical Science Team, RIKEN iTHEMS), Koji Hashimoto (Professor, Graduate School of Science, Kyoto University), Yoshihiro Kozuka (Creative Director, ADK Marketing Solutions), and Haruka Kodama (Experience Designer, ADK Marketing Solutions). From their respective professional perspectives, they exchanged ideas on collaborations between science and art. Professor Hashimoto also discussed his cross-disciplinary activities exploring the theme of “Quantum × Music,” including translating concepts from quantum physics into musical expression. This program was held as the second installment of an ongoing talk series. Following the first session, the discussion further explored the significance of initiatives that bridge academic research and creative practice. After the main event, a wrap-up talk featuring participating artists, creators, and researchers from the exhibition was also held, with the same members continuing the discussion.
-
2026-05-14
Hot Topic
iTHEMS x academist Online Event "World of Mathematical Sciences 2026" on April 18, 2026
RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS) held the online event “Exploring the World of Science through Mathematics 2026” on Saturday, April 18, 2026, in collaboration with academist Inc. The event featured a series of lectures spanning a wide range of scientific fields, all connected through the perspective of mathematical sciences. Junnosuke Koizumi, Osamu Fukushima, Muzi Hong, and Kenji Okubo each gave presentations in their respective areas of expertise. The talks incorporated concrete examples to facilitate understanding, and also included discussions with commentators as well as Q&A sessions with participants. In addition, during the lunch break, Honorary Research Scientist Shun-ichi Amari and iTHEMS Director Satoshi Iso led a special session titled “Intelligence and Learning in the Age of AI.” Through an interactive dialogue with practical examples, they discussed how AI is influencing human intellectual activity and transforming approaches to learning. According to the post-event survey, overall satisfaction with the event was high. While some participants commented that the presentations were “somewhat difficult,” many also described them as “easy to understand.” A total of 303 participants (528 cumulative attendees) joined the event, with the maximum number of simultaneous connections reaching 184.
-
2026-05-14
Paper of the WeekWeek 3, May 2026
Title: A Monte Carlo Study of the Dipolar Universality Class in Three Dimensions Author: Akira Matsumoto, Yu Nakayama, Toshiki Onagi, Slava Rychkov arXiv: http://arxiv.org/abs/2605.11573v1 Title: A stabilized dual-SAV parametric finite element framework for constrained planar geometric flows with mesh regularization Author: Koya Sakakibara arXiv: http://arxiv.org/abs/2605.11721v1 Title: Non-Parametric Equation of State Reveals Non-Conformal Behavior Beyond Neutron Star Densities Author: Yong-Jia Huang, Shao-Peng Tang, Yi-Zhong Fan arXiv: http://arxiv.org/abs/2605.08584v1 Title: Cooling of Isolated Neutron Stars with Hyperon-mixed Kaon-Condensation Matter Author: Bhavnesh Bhat, Akira Dohi, Takumi Muto, Tsuneo Noda arXiv: http://arxiv.org/abs/2605.09723v1 Title: Classification of Chimera States via Fourier Analysis and Unsupervised Learning Author: Rommel Tchinda Djeudjo, Riccardo Muolo, Thierry Njougouo, Timoteo Carletti arXiv: http://arxiv.org/abs/2605.09401v1 Title: Chemical Bond Analysis in Biomolecular Systems Using Intrinsic Atomic and Bond Orbitals (IAOs and IBOs) with PySCF Author: Mariia Ivonina doi: https://doi.org/10.26434/chemrxiv.15002966/v1 Title: Positivity of the gravitational path integral implies the axionic weak gravity conjecture Author: Gabriele Di Ubaldo, Luca V. Iliesiu, Henry W. Lin, Cynthia Yan arXiv: http://arxiv.org/abs/2605.05305v1
107 news in 2026