News
127 news in 2026
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2026-11-05
Paper of the WeekWeek 2, November 2026
Title: Statistical mechanics and hierarchy of learnability in quantum codes: From generalized symmetries to non-Abelian topological orders Author: Hiromi Ebisu, Masazumi Honda arXiv: http://arxiv.org/abs/2611.06154v1 Title: Quantum Computing for Entanglement Asymmetry and the Quantum Mpemba Effect in Field Theory Author: Keisuke Fujii, Harunobu Fujimura, Masazumi Honda, Duc Truyen Le arXiv: http://arxiv.org/abs/2611.05987v1 Title: Quantum 6j-symbols arising from a subfactor of finite index and finite depth and the zipper condition for 4-tensors in two-dimensional topological order Author: Yasuyuki Kawahigashi arXiv: http://arxiv.org/abs/2611.02582v1 Title: Enforced Gaplessness by Combining Non-Anomalous Symmetries Author: Takamasa Ando, Kantaro Ohmori arXiv: http://arxiv.org/abs/2611.03164v1 Title: Inner Product of Closed Universe from Gravitational Path-integral Author: Masamichi Miyaji, Sunil Sake, Kotaro Shinmyo arXiv: http://arxiv.org/abs/2611.03789v1 Title: Counting irreducible skew polynomials $x^{2n}+ax^n+1$ Author: Tomoya Hayata, Takahiro Tsushima arXiv: http://arxiv.org/abs/2611.04767v1 Title: Generalizable Equivariant Diffusion Models for Non-Abelian Lattice Gauge Theory: Analytical Foundations and Numerical Scaling Tests 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/2611.03530v1 Title: Summing over Seifert Manifolds in Narain Ensemble Averages Author: Kei Kaneda, Masahito Yamazaki arXiv: http://arxiv.org/abs/2611.02515v1 Title: Root-of-unity limit of the $A_{n-1}$ lens elliptic gamma function solution of the star-star relation Author: Masahito Yamazaki arXiv: http://arxiv.org/abs/2610.41438v1
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2026-11-05
Hot Topic
Farewell message from Muzi Hong
Our colleague, Muzi Hong, left iTHEMS on October 11, 2026, and has joined Fermilab as a Research Associate. We all miss her and wish her the best of luck in her new endeavor. Here is a message from Muzi: I had a wonderful time at iTHEMS. It was always a pleasure to discuss ideas with people from various fields and attend seminars on a wide range of topics. I enjoyed every Coffee Meeting. I also made many friends along the way. The secretaries were always kind and helpful. I would like to thank all my colleagues for creating such a friendly, welcoming, and professional environment at iTHEMS. I always look back on my time there with warmth and fond memories. I have now moved to Fermilab as a postdoc, but I will remain affiliated with iTHEMS as a visiting scientist. You are always welcome to visit me at Fermilab!
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2026-11-05
Featured Paper of the Week
When a little “group pressure” helps oscillators fall into step
A paper by Riccardo Muolo (iTHEMS), Hiroya Nakao (Institute of Science Tokyo), and Marco Coraggio (Scuola Superiore Meridionale, Italy), published in Chaos, has been selected as an Editor’s Pick and featured in AIP Publishing’s SciLight. Synchronization is everywhere in nature: fireflies flashing in unison, neurons firing together, power grids running at a common frequency. The standard way to study it mathematically is the Kuramoto model, in which many oscillators, each with its own natural rhythm, nudge one another towards a common beat. Traditionally, these nudges are assumed to happen in pairs. In many real systems, however, interactions involve three or more units at once. These group interactions, also called higher-order or nonpairwise interactions, are naturally described by hypergraphs rather than ordinary networks. Previous research on synchronization had painted a mostly pessimistic picture. Higher-order interactions make the synchronous state harder to reach, because they shrink the set of starting conditions that lead to it. The authors showed that this picture is incomplete. In fact, a systematic numerical study of Kuramoto oscillators on various hypergraph topologies confirmed that, indeed, strong higher-order interactions do work against synchronization. However, weak higher-order interactions, combined with pairwise ones, can instead enhance it, even when the oscillators start out completely disordered. This also appears in the thermodynamic limit, which shows that it is not a finite-size effect. The authors then asked a practical question. If the budget for connections is limited, how should it be split between pairwise and nonpairwise interactions? The answer is that a mixed allocation achieves stronger synchronization than investing everything in either type alone. Both these results clarify the role of higher-order interactions in collective dynamics and, most importantly, suggest design principles for engineering synchronization in complex systems. For further details, please see the article in Chaos and the SciLight feature listed in the References.
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2026-10-30
Hot Topic
Reproducing Long-Term Variations in Venus's Atmospheric Superrotation
A joint research team including Takemasa Miyoshi, Team Director at the RIKEN Interdisciplinary Theoretical and Mathematical Sciences Program (iTHEMS), has successfully reproduced long-term variations in the wind speeds of Venus's atmospheric "superrotation," a phenomenon characterized by extremely fast atmospheric circulation, using the Venus atmospheric data assimilation system ALEDAS-V. By incorporating wind observation data from the cloud tops collected by the Venus Climate Orbiter Akatsuki into numerical simulations, the team reproduced observed wind speed variations and differences between the northern and southern hemispheres. The researchers also estimated the three-dimensional structure of Venus's atmosphere, including altitudes where direct observations are unavailable. These findings demonstrate the potential of data assimilation techniques to reveal planetary atmospheric circulation patterns from limited observational data and are expected to contribute to future Venus exploration and planetary atmospheric research. For more details, please see the related links.
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2026-10-29
Paper of the WeekWeek 5, October 2026
Title: Trial-space co-design for quantum simulation on noisy hardware Author: Bo peng, Vibin Abraham, Himadri Pathak arXiv: http://arxiv.org/abs/2610.33246v1 Title: Two-Particle Correlation Function in a Finite Volume Author: Wren Yamada, Osamu Morimatsu, Toru Sato, Koichi Yazaki arXiv: http://arxiv.org/abs/2610.33681v1 Title: Fast and accurate rare-event simulation by Markov chain Monte Carlo for general quantum codes Author: Junichi Haruna, Kotaro Murakami arXiv: http://arxiv.org/abs/2610.35498v1 Title: Explaining the universal Hagedorn temperature in string models of hadrons with fixed endpoints or baryon junctions Author: Yuki Fujimoto arXiv: http://arxiv.org/abs/2610.34882v1 Title: Two-Pion Exchange Paradigm in Hadron-Hadron Interactions from Lattice QCD Author: Tetsuo Hatsuda Journal Reference: Journal of Subatomic Particles and Cosmology, 5 (2026) 100341 doi: https://doi.org/10.1016/j.jspc.2026.100341 arXiv: http://arxiv.org/abs/2610.34655v1 Title: Intertwining Defects and Fermion-Boundary Scattering from TQFT Author: Kantaro Ohmori, Masataka Watanabe, Pengcheng Wei, Yunqin Zheng arXiv: http://arxiv.org/abs/2610.31737v1 Title: Data analysis of millions of Type IIB flux vacua Author: Yuta Hamada, Yuma Uematsu, Masahito Yamazaki arXiv: http://arxiv.org/abs/2610.30273v1 Title: Dyon Condensation at $θ=2π$ from Wilson-'t Hooft Loops in Yang-Mills Theory Author: Hiromasa Watanabe, Issaku Kanamori, Okuto Morikawa, Yuki Nagai, Yuya Tanizaki, Akio Tomiya arXiv: http://arxiv.org/abs/2610.31281v1 Title: Surface Defects in the $\mathcal{N}=2$ Lens Space Index and Elliptic Integrability Author: Masahito Yamazaki arXiv: http://arxiv.org/abs/2610.30849v1
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2026-10-27
AwardDaisuke S. Shimamoto, Special Postdoctoral Researcher, Selected for the 59th (FY2026) Research Grant of the Ito Science Foundation
Daisuke S. Shimamoto, Special Postdoctoral Researcher in the Division of Fundamental Mathematical Science at the RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS), has been selected for funding under the 59th (FY2026) research grant program of the Ito Science Foundation. The program supports young researchers pursuing original basic research. This year, two projects each were selected in physics and biological sciences. Shimamoto’s project is titled “Degrees of Freedom and Constraints in Periodic Tangle Structures.” It focuses on structures formed by interwoven threads or interlinked rings, such as knitted fabrics and chain mail, and explores how these arrangements affect their susceptibility to damage and their shape. By combining mathematical and physical approaches, the research is expected to offer new insights into the mechanisms underlying these familiar structures. Congratulations, Daisuke!
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2026-10-27
Press Release
Are Supernovae Giant Cosmic Particle Accelerators? Exploring a PeVatron Candidate through Visible Light and Neutrinos
A collaborative research group including Ryo Sawada, a Special Postdoctoral Researcher at RIKEN iTHEMS, has theoretically shown that the Type Ibn supernova SN 2023uqf may act as a “PeVatron,” capable of accelerating particles to extremely high energies. By connecting the explosion environment inferred from visible-light observations with a high-energy neutrino event detected by IceCube, the study presents a new approach to investigating the origin of cosmic rays. For further details, please see the related link.
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2026-10-23
Award
Riccardo Muolo Receives the 2026 Complex Systems Society Emerging Award
Riccardo Muolo (Special Postdoctoral Researcher, Division of Fundamental Mathematical Science, RIKEN iTHEMS) has received the 2026 Emerging Award from the Complex Systems Society (CSS). The award was presented at the 2026 Conference on Complex Systems (CCS 2026), held in Binghamton, New York, USA, on October 9–16, 2026. The CSS Emerging Award recognizes promising early-career researchers who have made significant contributions to complex systems science within three years of completing their PhD. Riccardo was recognized for developing new mathematical tools to understand the complex interactions underlying collective dynamics, including synchronization, pattern formation, and self-organization, as well as for his contributions to scientific outreach and dissemination. This award highlights his contributions to the mathematical understanding of complex systems and the interdisciplinary nature of his research. Congratulations, Riccardo, on this wonderful achievement!
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2026-10-22
Paper of the WeekWeek 4, October 2026
Title: Surface defects on lens space and transfer matrices Author: Kazunobu Maruyoshi, Toshihiro Ota, Masahito Yamazaki arXiv: http://arxiv.org/abs/2610.28165v1 Title: Hubble Susceptibility: Beyond Effective-Mass Spectroscopy in the Cosmological Collider Author: Shuntaro Aoki, Masahide Yamaguchi arXiv: http://arxiv.org/abs/2610.26014v1 Title: Andreev Beta Conversion and Bulk Viscosity in Superfluid Neutron-Star Matter Author: Tingyu Zhang, Honoka Hoshino, Hiroyuki Tajima, Motoi Tachibana, Mariusz Sadzikowski arXiv: http://arxiv.org/abs/2610.23581v1 Title: Jianmu-Q: Bridging Quantum Field Theory and Quantum Hardware with AI Agents Author: Xiaolin Wang, Xingyu Guo, Jinyang Li, Tianyin Li, Enke Wang, Lingxiao Wang, Hongxi Xing arXiv: http://arxiv.org/abs/2610.21942v1 Title: Diffusion Language Models as Open Quantum Systems Author: Akinori Tanaka, Yukinao Akamatsu, Takuki Tomita, Yuji Hirono arXiv: http://arxiv.org/abs/2610.21672v1
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2026-10-20
Hot Topic
AI and Symmetry Accelerate the Design of Sound-Absorbing Woven Materials
An international research team including Sonia Mahmoudi, Assistant Professor at the Advanced Institute for Materials Research (AIMR), Tohoku University, and Visiting Scientist at iTHEMS's Tohoku University Collaboration Team, has developed a method that uses AI and symmetry to make the design of sound-absorbing woven materials more efficient. The researchers organized manufacturable weave patterns according to symmetry and trained an AI model on a limited set of detailed simulations, enabling rapid evaluation of many candidates. Predicted sound-absorption performance agreed with independent simulations within 5%. The team plans to test selected 3D-woven prototypes experimentally. For details, please see the related links.
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2026-10-15
Paper of the WeekWeek 3, October 2026
Title: Assessing evolutionarily significant units in a widespread species: morphology, demography, and adaptive divergence support multiple lineages in the southern range of Dioon tomasellii (Zamiaceae) Author: Brian L. Dorsey, José Said Gutiérrez-Ortega, Miguel Angel Pérez-Farrera, Timothy J. Gregory Journal Reference: Conservation Genetics doi: https://doi.org/10.1007/s10592-026-01845-z Title: How do variable patch sizes hold higher beta diversity? Author: Minagi Naka, Akira S Mori, Ryosuke Iritani Journal Reference: bioRxiv doi: https://doi.org/10.64898/2026.09.29.755527 Title: Evolutionary invasion analysis for structured populations: a synthesis Author: Ryosuke Iritani, Troy Day Journal Reference: bioRxiv doi: https://doi.org/10.64898/2026.03.23.713828 Title: The Evolutionary and Ecological Consequences of Cooperation Author: Stuart A. West, Anna E. Dewar, Ryosuke Iritani, Laurence. J. Belcher, Ashleigh S. Griffin Journal Reference: The American Naturalist, 207(4), 467-482 doi: https://doi.org/10.1086/739292 Title: Codimension-Zero Holographic Complexity and Spectral Three-Point Correlators Author: Masamichi Miyaji, Shan-Ming Ruan, Shono Shibuya, Kazuyoshi Yano arXiv: http://arxiv.org/abs/2610.13289v1 Title: Searching for Charged Lepton Flavor Violation Author: Lorenzo Calibbi, Kaori Fuyuto, Matthias Heinz, Jure Zupan arXiv: http://arxiv.org/abs/2610.11839v1 Title: Reconstructing BPS String Charge Cone in 6d N=(1,0) Supergravity Author: Yuta Hamada, Hee-Cheol Kim, Kai Xu arXiv: http://arxiv.org/abs/2610.10711v1
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2026-10-09
Hot Topic
Helping AI Recognize Shapes through Event Cameras: Paper by Masato Taki and Colleagues Accepted at NeurIPS 2026
A paper by Masato Taki, Team Director of the AI as Science Team at RIKEN iTHEMS and Associate Professor at Rikkyo University, together with Soshun Kihara and Shunsuke Yasuki, graduates of Rikkyo University's Graduate School of Artificial Intelligence and Science, has been accepted at NeurIPS 2026, a leading international conference in AI and machine learning. The researchers used knowledge distillation to transfer what an AI model learned from event-camera data, which capture changes in brightness at individual pixels, to a model processing conventional color images. The resulting model relied more on object shapes than on color or texture and became less sensitive to color changes and fine-grained noise. For details, please see Rikkyo University's press release via the related link.
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2026-10-08
Paper of the WeekWeek 2, October 2026
Title: Quantum Algorithms for Finding Vacua in the ADK Landscape Author: Shirabe Endo, Yuta Hamada arXiv: http://arxiv.org/abs/2610.07439v1 Title: Spin-1 Bulk Local States in AdS/CFT and Carrollian Holography Author: Peng-Xiang Hao, Kotaro Shinmyo, Kenta Suzuki, Yu-ki Suzuki, Shunta Takahashi arXiv: http://arxiv.org/abs/2610.07548v1 Title: Gravitational-wave Echoes Beyond the Hubble Time from Quantum Black Holes Author: Che-Yu Chen, Naritaka Oshita, Yuki Yokokura arXiv: http://arxiv.org/abs/2610.05886v1 Title: Entanglement Requires Fluctuations at Conformal Interfaces Author: Yuya Kusuki, Kosei Suzuyama, Yin Tang arXiv: http://arxiv.org/abs/2610.02309v1 Title: XMM-Newton Resolves Parsec-scale X-ray Jets in the PeVatron Microquasar V4641 Sgr Author: Naomi Tsuji, Caterina Tresoldi, Kaya Mori, Hiromasa Suzuki, Matthew Lundy, Dmitry Khangulyan, Samar Safi-Harb, Laura Olivera-Nieto, Felix Aharonian, Shotaro Abe, Zhen Cao, Sabrina Casanova, Maria Chernyakova, Yi-Heng Chi, Stephane Corbel, E. de la Fuente, Hua Feng, Tatsuki Fujiwara, Noa Grollimund, Dezhi Huang, Yoshiyuki Inoue, Ryohei Kanazashi, Shigeo S. Kimura, Marianne Lemoine-Goumard, Jonathan Mackey, Alessio Marino, Samaresh Mondal, Kai Morita, Maxime Parra, Gabriele Ponti, Brian Reville, Megumi Shidatsu, Shunya Takekawa, Michelle Tsirou, Xiaojie Wang, Heshou Zhang, Ping Zhou arXiv: http://arxiv.org/abs/2610.02966v1 Title: Quantum Krylov Learning Author: Shunji Matsuura, Yoji Kawamura, Joseph Salfi, Satoshi Iso arXiv: http://arxiv.org/abs/2610.00537v1 Title: Generative Modeling of Stochastic Dynamics for Long-Time Evolution Author: Yang-yang Tan, Jinyang Li, Lingxiao Wang arXiv: http://arxiv.org/abs/2610.00546v1 Title: Dissipation-Sensitivity Trade-Off in Dissipative Bosonic Systems Author: Kohei Yoshimura, Ryusuke Hamazaki arXiv: http://arxiv.org/abs/2610.01112v1 Title: Quantum computing for neuroscience: opportunities beyond classical limits Author: Annemarie Wolff, Alexandre Choquette, Georg Northoff, Atsushi Iriki, Guillaume Dumas Journal Reference: Nat. Rev. Neurosci. (2026) doi: https://doi.org/10.1038/s41583-026-01083-9
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2026-10-08
Award
Tomoki Ozawa was awarded the 30th Matsuo Foundation Hiroshi Takuma Memorial Academic Award
Tomoki Ozawa, Team Director of the Tohoku University Collaboration Team at RIKEN iTHEMS, has been awarded the 30th (FY2026) Matsuo Foundation Hiroshi Takuma Memorial Academic Award for his research on "Topological physics in AMO systems, particularly synthetic dimensions." The award ceremony will be held on December 7, 2026. The Matsuo Foundation Hiroshi Takuma Memorial Academic Award is presented annually by the Matsuo Foundation to one researcher who has achieved outstanding results in atomic and molecular physics and quantum electronics. Congratulations, Tomoki!
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2026-10-08
Award
Lingxiao Wang Receives 2026 Google TPU Builders Research Award
Lingxiao Wang, Deputy Team Director of the AI as Science Team at RIKEN iTHEMS, has received the 2026 Google TPU Builders Research Award for his research, "Physics-Driven Diffusion Samplers on TPUs." The award was granted under Google's 2026 Awards for Machine Learning Research and Education with TPUs. The Google program supports the advancement of machine learning through both foundational and applied research, as well as the design and execution of courses that feature Google TPUs. The project aims to combine physics-driven generative models with large-scale computing resources to develop efficient and scalable sampling methods for challenging problems in lattice field simulations. This support will help advance research at the intersection of generative AI, high-performance computing, and quantum field theory. Congratulations, Lingxiao!
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2026-10-05
Hot Topic
ECL Unit Leader Leo Speidel elected a 2026 AYS Fellow in Life Sciences
Leo Speidel, a RIKEN ECL Unit Leader at the RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS) and RIKEN Pioneering Research Institute(PRI), has been elected as a 2026 Asian Young Scientist (AYS) Fellow in Life Sciences. AYSF is a privately funded research fellowship that aims to encourage and support young scientists in Asia to carry out creative and transformative research. The Fellowship annually selects early-career scientists in three fundamental disciplines: 1) Life Science, 2) Physical Science, and 3) Mathematics and Computer Science. Speidel’s research focuses on the development and application of new mathematical and statistical techniques to reveal human evolution, with the goal of reconstructing genome-wide genealogies across individuals and species. He was selected for this year’s AYSF in recognition of his pioneering achievements.
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2026-10-01
Paper of the WeekWeek 1, October 2026
Title: Higher-dimensional full vertex algebras and systems of conformally covariant correlation functions Author: Yuto Moriwaki arXiv: http://arxiv.org/abs/2609.37949v1 Title: Emergent Symmetries in Ensemble Averages Author: Masahito Yamazaki arXiv: http://arxiv.org/abs/2609.36542v1 Title: Dimensional (In)dependence of Lorentzian Quantum Cosmology Author: Masazumi Honda, Hiroki Matsui, Kota Numajiri, Kazumasa Okabayashi, Takahiro Terada arXiv: http://arxiv.org/abs/2609.33452v1 Title: A gravitational realization of Courant-Hilbert deformations Author: Osamu Fukushima, Miyabi Kurihara, Takaki Matsumoto, Kentaroh Yoshida arXiv: http://arxiv.org/abs/2609.35452v1 Title: Local Combinatorial Criteria for Geometric Hyper-ideal Triangulations via Combinatorial Ricci Flow Author: Soichiro Uemura arXiv: http://arxiv.org/abs/2609.34108v1 Title: Dyonic edge modes in Abelian gauge theory Author: Keito Shimizu, Sotaro Sugishita arXiv: http://arxiv.org/abs/2609.30964v1 Title: Mitochondrial genetic diversity and population structure of the Gila eremica lineage across river basins in Sonora, northwestern Mexico Author: Carlos A., Ballesteros-Córdova, Alejandro Varela-Romero, Gorgonio Ruiz-Campos, Lloyd T. Findley, José Said Gutiérrez-Ortega, José M. Grijalva-Chon, Luis E. Gutiérrez-Millán Journal Reference: Environmental Biology of Fishes doi: https://doi.org/10.1007/s10641-026-01914-9
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2026-10-01
Hot Topic
Farewell message from Osamu Fukushima
Our colleague, Osamu Fukushima, will be joining the Faculty of Science and Engineering, Doshisha University, as an Assistant Professor. We will all miss him and wish him the best of luck in his new endeavor. Here is a message from Osamu: I would like to express my sincere gratitude to everyone at iTHEMS as I leave my position as a Special Postdoctoral Researcher. During my time at iTHEMS, I greatly benefited from its open and interdisciplinary research environment. My research has mainly focused on theoretical and mathematical physics, but interactions with researchers from a wide range of fields encouraged me to broaden my perspective and explore new research directions. I especially appreciated the many stimulating discussions, seminars, and informal conversations at iTHEMS. They often gave me new ideas and perspectives that I would not have encountered within my own field. I would like to thank all the researchers, assistants, and staff for their support and for making iTHEMS such a welcoming place to work. Although I am leaving iTHEMS, I hope to stay connected and continue interacting and collaborating with its members in the future. It has been a great pleasure to be part of the iTHEMS community.
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2026-09-30
Hot Topic
Workshop “Quantum Information: Entanglement of Mathematics & Physics” Held at UBC
From September 21 to 23, 2026, iTHEMS held the workshop “Quantum Information: Entanglement of Mathematics & Physics” at the University of British Columbia (UBC) in Vancouver, Canada. The workshop brought together researchers in mathematics and physics to foster cross-disciplinary discussion through the shared lens of quantum information. Its wide-ranging program covered operator algebras, quantum resource theories, quantum gravity, condensed-matter physics, quantum computing, and quantum error correction. Participants discussed entanglement in these different fields and the mathematical structures underlying quantum information. Approximately 40 researchers from iTHEMS, UBC, and other universities and research institutions in Japan and Canada participated in the workshop. Over the three days, 21 talks were presented. Generous time was also allocated each day for discussion, allowing participants from different fields to share their perspectives and research methods and to engage in lively exchanges. Viewing the participants’ research through the common perspective of quantum information revealed many concrete ways in which insights and methods from distinct fields can complement one another. The broad range of expertise represented by researchers from Japan and Canada gave depth to the discussions and enabled an organic exchange of ideas, with candid questions and challenges addressed across disciplinary boundaries. On the final day, a plenary discussion entitled “Entanglement across mathematics and physics; future iTHEMS–UBC collaboration” explored how the exchanges initiated at the workshop could lead to future research collaboration between iTHEMS and UBC. The workshop also provided a valuable opportunity to build relationships toward sustained academic exchange and a possible Memorandum of Understanding (MOU) between the two institutions. By connecting diverse areas of mathematics and physics through quantum information, the workshop expanded opportunities for new exchanges and collaborative research, while further strengthening the partnership between iTHEMS and UBC.
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2026-09-29
Hot Topic
Mathematical Genomics RIKEN ECL Research Unit Joins OIST Mirror Lab
The Mathematical Genomics RIKEN ECL Research Unit, led by RIKEN ECL Unit Leader Leo Speidel at iTHEMS, has joined an OIST Mirror Lab together with research groups from the Okinawa Institute of Science and Technology (OIST), the Max Planck Institute, and Karolinska Institutet. Mirror Labs are a framework established by OIST to foster long-term research partnerships with institutions in Japan and abroad. Through joint research, researcher exchanges, and the development of early-career researchers, Mirror Labs promote sustained collaboration that brings together the complementary expertise of participating research groups. The newly established “The Evolutionary History of Archaic and Modern Humans Mirror Lab” brings together research groups from OIST, the Max Planck Institute, Karolinska Institutet, and RIKEN to investigate human evolution and population history using genomic data from Neanderthals, Denisovans, and modern humans. The collaboration will explore topics including genetic admixture between archaic and modern humans and the more recent population history of modern humans, particularly in the Japanese Archipelago. The unit will contribute its expertise in population genetic analyses to research on human migration, admixture, and evolution through analyses of modern and ancient genomes.
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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
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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 Special Postdoctoral Researcher Keiya Hirashima of the Division of Fundamental Mathematical Science at the RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS) has been selected as a finalist for the 2026 ACM Gordon Bell Prize for their research achievements on a high-resolution simulation of the Milky Way galaxy using multiple GPU supercomputers. The research group also includes researchers from the University of Tokyo, Kobe University, Flatiron Institute, University of Tsukuba, Tohoku University of Community Service and Science, Hokkaido University, and the University of Barcelona.
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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
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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
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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
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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.
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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.
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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
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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
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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
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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
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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.
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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
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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
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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.
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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!
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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
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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.
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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.
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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
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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.
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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!
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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.
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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
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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
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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.
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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.
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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
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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
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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.
127 news in 2026