Tannaka duality for spectral sheaves on compact Hausdorff spaces

September 17 (Thu) 15:00 - 16:30, 2026

Ko Aoki (Postdoc, University of Copenhagen, Denmark)

Tannaka duality asks to what extent a geometric object can be recovered from a category naturally associated with it. In this talk, the geometric objects are topological spaces, and the associated categories are their categories of sheaves of spectra. I showed that, for compact Hausdorff spaces X and Y, every colimit-preserving symmetric monoidal functor from Shv(X; Sp) to Shv(Y; Sp) arises uniquely from a continuous map from Y to X, where Shv(X; Sp) denotes the (∞, 1)-category of sheaves of spectra on X. The main ingredient is an adjunction between the construction of sheaves and a new variant of the smashing spectrum. I will also discuss variants of this machinery to broader classes of spaces, including ongoing work on toposes.

Venue: via Zoom / Seminar Room #359

Event Official Language: English

Quantum Information: Entanglement of Mathematics & Physics

September 21 (Mon) - 23 (Wed) 2026

This workshop brings together mathematicians and physicists to explore the deep connections among quantum information, mathematics, and physics. Topics span quantum gravity, condensed matter physics, quantum computing, and quantum error correction, with an emphasis on the mathematical structures that underlie entanglement and quantum information across these fields. The program is designed to foster genuine cross-disciplinary dialogue, allowing ample time for discussion alongside formal talks. [Invited speakers] Akira Furusaki (RIKEN CEMS/iTHEMS) Marcel Franz (UBC / SBQMI) Ching-Kai Chiu (iTHEMS) Jasmin Bedow (UBC) Max McGinley (UBC) Yosuke Kubota (Kyoto University) Shunji Matsuura (RIKEN iTHEMS) Bartosz Regula (RIKEN RQC) Ryuji Takagi (University of Tokyo) Sisi Zhou (Perimeter Institute) Olivia Di Matteo (UBC / SBQMI) Daochen Wang (UBC Computer Science) Polina Feldmann (UBC) Masazumi Honda (RIKEN iTHEMS) Yasuyuki Kawahigashi (RIKEN iTHEMS) Carolyn Zhang (UBC) Masahito Yamazaki (Kavli IPMU, University of Tokyo) Aswin Parayil Mana (University of Tokyo) Alex May (Perimeter Institute) Masamichi Miyaji (RIKEN iTHEMS) Mark Van Raamsdonk (UBC Physics & Astronomy)

Venue: University of British Colombia

Event Official Language: English

Workshop on Gestalt

September 24 (Thu) - 30 (Wed) 2026

Ko Aoki (Postdoc, University of Copenhagen, Denmark)

Note. The lectures will be given in Japanese. This workshop will be jointly organized by RIKEN AIP. During this five-day workshop, we will hold a learning seminar and intensive lectures on gestalt theory, which was recently developed by Scholze and Stefanich. Gestalt theory is a new geometric framework that unifies various derived analytic geometry and higher sheaf theory, building on the foundations of higher and derived category theory. At this event, we will host Ko Aoki, who has contributed to the foundations and development of the theory, for the intensive lecture session. During the first three days of the workshop, we will feature tutorial lecture sessions, presented by the participants. All lectures will be given in Japanese, with the aim of promoting the dissemination and development of gestalt theory in Japan.

Venue: Yagami Campus, Keio University

Event Official Language: Japanese

Foundations of Quantum Programming Lecture

September 28 (Mon) - October 2 (Fri) 2026

Mingsheng Ying (Professor, University of Technology Sydney, Australia)

Lecture Professor Mingsheng Ying is internationally recognised for his contributions to quantum computing, quantum programming, and quantum software verification. He is a Distinguished Professor at the UTS Centre for Quantum Software and Information at the University of Technology Sydney. His research interests include quantum computation, programming language theory, quantum program semantics, verification, and the foundations of quantum software. Professor Ying is Co-Editor-in-Chief of ACM Transactions on Quantum Computing and has served in editorial roles for several leading journals and conferences. Abstract Recent advances in quantum hardware have brought the field from prototype devices to increasingly practical platforms. To fully realise the potential of quantum computing, quantum programming and software-development technologies will play a crucial role. This lecture series systematically introduces the theoretical foundations of quantum programming, including operational and denotational semantics, quantum program logics with an emphasis on quantum Hoare logic, verification and analysis of quantum programs, and quantum recursive programming. The lectures will also discuss open problems that may inspire future research in quantum programming.

Venue: Room C502, West Zone 1 Building D, Ito Campus, Kyushu University, SUURI-COOL (Kyushu) (Main Venue) / via Zoom

Event Official Language: English

Foundations of Quantum Programming Mini-Workshop & Contributed Talks

September 28 (Mon) - October 2 (Fri) 2026

Mingsheng Ying (Professor, University of Technology Sydney, Australia)
Hiroyuki Ochiai (Professor, Institute of Mathematics for Industry, Kyushu University)
Jianjun Zhao (Professor, Kyushu University)
Minh Canh Do (Instructor, Japan Advanced Institute of Science and Technology)

Venue: Room C502, West Zone 1 Building D, Ito Campus, Kyushu University, SUURI-COOL (Kyushu) (Main Venue) / via Zoom

Event Official Language: English

Adaptive Regulation through Model-Observation Mismatch: From Process Control to Cognitive Neurorobotics

October 8 (Thu) 13:00 - 14:00, 2026

Henrique Oyama (Postdoctoral Researcher, Cognitive Neurorobotics Research Unit, Okinawa Institute of Science and Technology Graduate University (OIST))

Adaptive behavior requires biological and artificial systems to respond when their internal models no longer match what they observe. How can such discrepancies be used not only to correct predictions, but also to regulate how a system interacts with its environment? In this talk, I will explore this question across two research directions spanning process control and cognitive neurorobotics. First, I will introduce a model predictive control framework in which a controller actively guides a nonlinear process toward informative conditions to distinguish among competing models while maintaining safe operation. I will then move to cognitive neurorobotics, where brain-inspired computational principles are used to investigate perception, prediction, and action in embodied artificial agents. In physical human-robot interaction, I will show how a predictive-coding-inspired recurrent neural network enables a humanoid robot to regulate the balance between its learned expectations and sensory information arising from human-guided movements. In particular, recent mismatches between sensory observations and the robot's internal model are used to regulate how strongly it relies on its learned dynamics or accommodates ongoing interaction. Together, these studies illustrate how model-observation mismatch can provide a general signal for adaptive regulation, connecting ideas from control engineering, artificial intelligence, neuroscience, and embodied cognition.

Venue: Hybrid Format (3F #359 and Zoom), Main Research Building / via Zoom

Event Official Language: English

Quantum Computing for Nuclear Physics (QC-NP 2026)

October 13 (Tue) - 16 (Fri) 2026

Join us for a comprehensive workshop on the application of quantum computing to nuclear physics, bringing together experts from around the world to share the latest developments and advancements in this rapidly evolving field. The workshop will cover a broad range of topics, including quantum algorithms, quantum computing hardware, and their applications to lattice field theories, gauge field theories, scattering, nuclear structure, and nuclear astrophysics. The workshop will provide ample opportunities for participants to exchange ideas, share their research, and initiate new collaborations. Through a combination of presentations and interactive discussion sessions, we aim to foster a collaborative environment that drives innovation and advances our understanding of the intersection of quantum computing and nuclear physics. [Workshop Schedule] The workshop will start from the morning of October 13 The banquet will be held on the evening of October 15 [Important Dates] Registration deadline with oral presentation: August 31, 2026 Recommended to register by: August 31, 2026 [Invited Speakers] A. Baha Balantekin (University of Wisconsin Madison) Raul Briceño (University of California Berkeley/Lawrence Berkeley National Laboratory) Philipp Höhn (Okinawa Institute of Science and Technology Etsuko Itou (Kyoto University) Dima Kharzeev (Brookhaven National Laboratory/Stony Brook University) Yuta Kikuchi (Quantinuum) Denis Lacroix (IJCLab) Dean Lee (Michigan State University) Mario Motta (IBM Quantum) Takeshi Sato (University of Tokyo) Ionel Stetcu (Los Alamos National Laboratory) Paul Stevenson (University of Surrey) Nathan Wiebe (University of Toronto) Seiji Yunoki (RIKEN) [Organizers] Ermal Rrapaj (Lawrence Berkeley National Laboratory/RIKEN, Chair) Carlo Barbieri (University of Milan) Tetsuo Hatsuda (RIKEN) Masaaki Kimura (RIKEN/University of Tokyo) Haozhao Liang (University of Tokyo) Tomoya Naito (University of Tokyo/RIKEN) Enrico Prati (University of Milan) Alessandro Roggero (University of Trento) Takeshi Sato (University of Tokyo)

Venue: Faculty of Science Bldg.1, School of Science, The University of Tokyo, Hongo Campus

Event Official Language: English

From data to cohomologies of digraphs, to representations of categories

October 13 (Tue) 10:30 - 12:00, 2026

Luigi Caputi (Research Fellow, Department of Mathematics, University of Bologna, Italy)

Motivated by applications to topological data analysis, in the last years we have been witnessing a growing interest in new (topological, homological, categorical) features associated to graphs. The aim of the talk is to describe a recently developed (co)homology theory of directed graphs, called multipath cohomology, whose definition is inspired by Khovanov homology of knots. We will show its relations with more established invariants, such as chromatic homology of graphs, Hochschild homology of algebras, and matching complexes. If time allows it, we will show that the ranks of multipath cohomology, when restricted to graphs with bounded genus, grow at most polynomially in the number of edges, and that the order of its torsion is bounded. This will depend upon structural properties of (the representation category of) graphs, such as its Noetherianity properties.

Venue: #359, 3F, Main Research Building (Main Venue) / via Zoom

Event Official Language: English

Majorana Modes: Fundamentals, Status & Directions

October 13 (Tue) - 16 (Fri) 2026

Workshop Overview Majorana modes lie at the heart of contemporary condensed-matter physics, exhibiting non-Abelian exchange statistics; when protected by topology, they are robust against environmental perturbations. Here, “Majorana mode” is used broadly to include a localized zero-energy Majorana state (a Majorana zero mode) and chiral Majorana edge states with gapless dispersion crossing zero energy. This three-day in-person workshop returns to fundamentals and open questions. It opens with a tutorial session on the afternoon of October 13 for non-experts and adjacent fields, and emphasizes rigorous theory–experiment dialogue, robust methodology, and concrete benchmarks for realizing and testing Majorana modes. Participants Experimentalists and theorists working on Majorana modes Researchers in adjacent fields (quantum materials, superconductivity, mesoscopic physics) Graduate students and postdocs interested in entering the field Topics include (non-exhaustive) Majorana zero modes in a variety of nanostructures Chiral Majorana edge states in quantum spin liquids and other platforms Disorder, interactions, and realistic device modeling Experimental diagnostics and “smoking gun” signatures Topological Quantum Spin Systems

Venue: Okochi Hall

Event Official Language: English

AI and Scientific Discovery

October 19 (Mon) 14:00 - 15:30, 2026

Joseph Ledsam (Google Health Lead, Japan, Google Japan)

Artificial intelligence is having a transformative impact on health and scientific discovery. This presentation will trace the evolution from foundational breakthroughs to the sophisticated capabilities of today's large-scale AI models. It will explore how these advanced systems are creating new possibilities across the healthcare landscape, from accelerating therapeutic development to enhancing diagnostic processes and interpreting complex medical data. The session will also take a deeper look at the future possibilities for AI in health and explore the emerging role of agentic AI in scientific discovery. The core theme is the responsible development of AI to create tools that assist scientists, support healthcare professionals, and empower users. Bio: Dr Joseph Ledsam leads Google Health in Japan, where he works across AI research, digital health and health in Google products. He has led research in medical AI, genomics and drug discovery published in journals including Nature, Nature Medicine and Nature Methods. Before moving to Japan he worked as a medical doctor in the UK, and founded the Health Research and Genomics teams in Google DeepMind. He obtained his medical degree from The University of Leeds, UK, and was a research fellow at University College London during his clinical residency.

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

Event Official Language: English

A non-negative matrix factorization-based approach to integrating multimodal omics data with automatically tuned hyperparameters

November 16 (Mon) 14:00 - 15:00, 2026

Dorothy Ellis (Postdoctoral Researcher, Laboratory for Integrative Genomics, RIKEN Center for Integrative Medical Sciences (IMS))

Venue: via Zoom

Event Official Language: English

KEK(-iTHEMS) Theory Workshop 2026

November 25 (Wed) - 27 (Fri) 2026

Hirotaka Hayashi (Professor, Department of Physics, School of Science, Tokai University)
Hikaru Kawai (Visiting Professor, Nambu Yoichiro Institute of Theoretical and Experimental Physics (NITEP), Osaka Metropolitan University)
Takato Mori (Ph.D. Student, Department of Particle and Nuclear Physics, School of High Energy Accelerator Science, The Graduate University for Advanced Studies (SOKENDAI))
Masaya Nakagawa (Assistant Professor, Department of Physics, Graduate School of Science, The University of Tokyo)
Masaki Shigemori (Professor, Department of Physics, Graduate School of Science, Nagoya University)
Tadashi Takayanagi (Professor, Yukawa Institute for Theoretical Physics, Kyoto University)
Norihiro Tanahashi (Program-Specific Associate Professor, Department of physics, Graduate School of Science, Kyoto University)
Tatsuya Yamaoka (Ph.D. Student, Department of Physics, Graduate School of Science, The University of Osaka)

The KEK Theory Workshop is an annual workshop on string theory and quantum field theory. Since 2014, it has been held every winter as an international workshop and has become one of the major annual events in the high-energy physics community in Japan. This year’s workshop will be held on site at the KEK Tsukuba Campus from November 25 to 27, and it will be jointly organized with RIKEN iTHEMS. The workshop this year aims to provide a forum for extensive discussions on recent developments in string theory, matrix models, gauge/gravity duality, black-hole microstates, lattice constructions of chiral gauge theories, and open quantum systems.

Venue: Seminar Hall, Building 3, KEK Tsukuba Campus

Event Official Language: English

iTHEMS NOW & NEXT 2027

July 13 (Tue) - 15 (Thu) 2027

We will hold our annual gathering, **“iTHEMS NOW & NEXT 2027,” from July 13 to 15, 2027**. iTHEMS NOW & NEXT has traditionally been a two-day in-house event, providing an important opportunity for all iTHEMS members, including visiting researchers and new members, to gain a comprehensive overview of current activities across iTHEMS, to learn about research beyond their own fields, and to discuss where iTHEMS should go next. In 2027, we will **expand NOW & NEXT from two to three days** and, for the first time, invite leading researchers from outside iTHEMS across a broad range of research fields. While the first two days will retain the main character of our traditional in-house gathering, the extended three-day format is intended to create a broader opportunity for scientific exchange and, in particular, to enable leading researchers from outside iTHEMS to become better acquainted with our research activities and with the researchers who make up the iTHEMS community. As in previous years, the program will present activities across iTHEMS, including those of its divisions, research teams, working groups, and study groups, together with research presentations and poster sessions by iTHEMS members. Particular emphasis will be placed on communication across disciplinary and organizational boundaries and on identifying emerging research directions and opportunities for new collaborations. The additional third day will build on the presentations and discussions of the preceding two days and provide an opportunity for invited researchers to gain a deeper understanding of the breadth and strengths of research at iTHEMS and to interact directly with our members. We hope that these exchanges will not only introduce iTHEMS and its researchers more widely to leading scientists in different fields, but also bring new perspectives to our community and open possibilities for future scientific interactions and collaborations. Through this expanded three-day NOW & NEXT 2027, we hope to share where iTHEMS is now and where it is heading next, both within our own community and with leading researchers from outside iTHEMS, and to explore together new possibilities for the future development of iTHEMS.

Venue: 2F Large Conference Room, Administrative Headquarters, RIKEN Wako Campus (Main Venue) / via Zoom

Event Official Language: English