RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences

Utilizing Every Possible Method to Challenge the Ultimate Goal - Masazumi Honda

What are the fundamental building blocks of the universe? What is the ultimate physical law that govern the universe? How did the universe begin? Theoretical high energy physics, which seeks to answer these profound questions, is the main research field for Masazumi Honda. We spoke with Honda about his journey to iTHEMS, the breadth of his research approaches and disciplines, and his recent research on applying quantum computers to high energy physics. Please see the full article via the related link.

2025-05-15

iTHEMS x academist online event was held on April 19, 2025

iTHEMS held an online lecture event for the general public with the help of Academist Inc., on April 19, 2025. This year’s speakers were Yuuka Kanakubo, Kan Kitamura, Leo Speidel, and Yuki Yokokura, who delivered clear and easy-to-understand lectures that even middle school students could comprehend. Each speaker also served as a commentator for other lectures and facilitated Q&A sessions based on audience questions. During the lunch break, as part of the lunch program, Director Iso, a physicist, and Prof. Fumiharu Kato, a mathematician, engaged in a discussion about the future possibilities of mathematics, moderated by Ms. Shinozaki. The event was organized and hosted by Ms. Michibayashi and Mr. Katada from Academist, who helped make the event a success. The event was attended by 414 people, and at one point there were over 250 in the audience.

2025-04-23

Masazumi Honda received "Commendation for Science and Technology: the Young Scientists' Award"

Our colleague Masazumi Honda received "Commendation for Science and Technology: the Young Scientists' Award" in recognition of his outstanding research achievements in the theoretical studies of strong-coupling dynamics in quantum field theories. Congratulations to Masazumi !

2025-04-17

RIKEN Research: When it comes to modeling, even unmeasurable data tells us something

Mathematical models for predicting how cancer tumors in mice grow over time can give distorted results if unmeasurable data is ignored, a team that includes two RIKEN researchers has shown1. This finding has important implications when applying mathematical models to medicine. A self-confessed data geek, Catherine Beauchemin of the RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS) specializes in applying the power of math to everything from viruses to supernovae. “I love trying to figure out what data are telling us,” she says. Seeking new insights into cancer mechanisms, Beauchemin’s team used mathematical models to analyze previously published data of tumor-size measurements over time for ten mice. To read more, please visit the related link.

2025-04-14

RIKEN Research: Refined test could improve Parkinson’s disease diagnosis

A team that includes a RIKEN researcher has refined a lab test for measuring protein aggregate levels in samples from patients with certain neurodegenerative diseases1. This has the potential to improve diagnosis and drug development for these diseases. Synucleinopathies are neurodegenerative diseases such as Parkinson’s disease and dementia with Lewy bodies. They are associated with the accumulation of aggregates of misfolded alpha-synuclein proteins in the brain and spinal cord. “When a misfolded alpha-synuclein protein in a neuron encounters one of its properly folded counterparts, it causes it to become misfolded,” says Catherine Beauchemin of the RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences. “The two misfolded alpha-synuclein proteins stick together and cause other normal alpha-synuclein to misfold and aggregate.” To read more, please visit the related link.

2025-04-14

Demonstration of Quantum Information Delocalization in a Periodically Driven System

A collaborative research team, including Visiting Scientists Yuta Kikuchi and Tomoya Hayata, has demonstrated that a scrambled state—in which quantum information becomes delocalized—can be prepared using a quantum circuit that simulates a periodically driven system. This was achieved with an ion-trap quantum computer. Scrambled states possess characteristics that are expected to be beneficial for quantum information recovery and many-body quantum system computations. This achievement represents an early-stage application of quantum computing in an academic research domain where physical phenomena and quantum information intersect, and is anticipated to contribute to the promotion of quantum computing utilization in Japan. In this study, the research team confirmed that a scrambled state—previously typically discussed using random quantum circuits—can also be prepared using periodically driven quantum circuits. This was validated through a combination of practical implementation on a high-fidelity quantum computer, appropriate error mitigation techniques, and theoretical analysis. For further details, please refer to the press release available via the related link.

2025-04-14

RIKEN NEWS: Exploring Critical Magnetic Transport Phenomena with a Quantum Simulator

An interview with Yuta Sekino (Postdoctoral Researcher, iTHEMS) has been featured in Research Highlights, part of the "Close-up RIKEN 2025" series on RIKEN’s research introduction page. It has also been published in SPRING 2025 issue of RIKEN’s public relations magazine, RIKEN NEWS. Postdoctoral Researcher Yuta Sekino is theoretically investigating the behavior of "many-particle systems," which are collections of particles. He devised a new model that captures the flow of magnetism by confining individual atoms in an ultrafine lattice (optical lattice) created with lasers. Through theoretical calculations based on this model, he discovered a mysterious magnetic transport phenomenon. For more details, please see the related link.

2025-04-14

Greeting from the Director, Satoshi Iso

<strong>This April, iTHEMS entered a new phase with a renewed and expanded structure.</strong> While we continue to grow and evolve, the spirit of iTHEMS remains unchanged.

2025-04-09

RIKEN NEWS: Unraveling the Evolutionary Mechanisms of Cooperative Behavior Using Fugaku

An interview article with Yohsuke Murase (Senior Research Scientist) has been featured in Research Highlights, part of the "Close-up RIKEN 2025" series on RIKEN’s research introduction page. It has also been published in SPRING 2025 issue of RIKEN’s public relations magazine, RIKEN NEWS. We humans, often described as social animals, engage in "cooperative behavior"—working together and helping one another. Focusing on the key role played by "reputation," Dr. Yohsuke Murase and an international research team analyzed the dynamics of this information using the supercomputer Fugaku. Their findings revealed the evolutionary path of humanity, shaped by cooperative behavior. For more details, please refer to the related links.

2025-04-08

Takashi Tsuboi Appointed Honorary Research Fellow at RIKEN

The former Deputy Program Director of iTHEMS, Takashi Tsuboi, has been appointed "Honorary Research Fellow" at RIKEN by President Makoto Gonokami, effective April 1, 2025.This honor recognizes Takashi’s many years of distinguished service as Deputy Program Director of iTHEMS (FY2017–FY2024), as well as his outstanding achievements and dedicated contributions. He will continue to support iTHEMS as a Senior Visiting Scientist. Congratulations, Takashi!

2025-04-08

 A Century of Quantum Mechanics

 Interview with Mathematician Takashi Tsuboi [Part Ⅱ]

 Interview with Physicist Yasunori Nomura - Part Ⅳ

 Interview with Physicist Yasunori Nomura - Part Ⅲ

 Interview with Mathematician Takashi Tsuboi [Part Ⅰ]

 Interview with Mathematician Yuto Moriwaki [Part2]

 Interview with Mathematician Yuto Moriwaki [Part 1]

 Interview with Mathematician Eiji Inoue [Part 2] (in Japanese)

 Interview with Physicist Yasunori Nomura - Part Ⅱ

 The Connection Between Mathematics and Microbial Research: From Fisheries Science to the Path of Mathematics

 Contributed to the 'One Poster per Household' Project – Like the Ones You See in Science Classrooms

 Interview with Dr. Misako Tatsuma, a Planetary Formation Theorist

 Interview with Mathematician Eiji Inoue [Part 1]

 Interview with Physicist Yasunori Nomura - Part I

 Interview with Physicist Ryo Namba [Part 2]

 Interview with Physicist Ryo Namba [Part 1]

 Interview with Ryosuke Iritani, Mathematical Biologist [Part 1]

 Theoretical Physicist Tetsuo Hatsuda Interview Vol.2: About Research and Mathematics

 Theoretical Physicist Tetsuo Hatsuda Interview Vol.1: About RIKEN iTHEMS

 What about climate change in actuality?

 Statistical Signatures of Quantum Chaos in Non-Hermitian Systems

 Computers as a Playground for Mathematics

 The Free Will Theorem in Quantum Mechanics

 Renormalization revisited

 Renormalization: Awareness of Ignorance

 Recipe for soup of quarks and gluons

 A subjective view on what is a quantum effect

 Mathematical aspects of the entropic uncertainty relation

 Forming black holes from stars

 Singularity Theorems

 Resurgence: making sense out of non-convergent series

 How can we use a quantum computer to study the ground state of the hydrogen molecule?

 Applications and Extensions of the Nielsen-Ninomiya Theorem in Condensed Matter Physics

 COVID-19: then, now, and into the future

 Exploring Quantum Spacetime

 Classical simulations of quantum computers

 When a Cretan says all Cretans are liars

 Physical and local observables in gravitational theory

 Can you hear the shape of a drum?

 Quantum many-body physics with cold atoms

 complexity in non-unitary dynamics of photons

 Physics Through the Looking Glass

 A new B.O.A.T. in astrophysics

 Evolution and our daily rhythms

 Area law of entanglement entropy in quantum many body systems and its implication in tensor network calculation

 Comparison between conventional computers and quantum computers

 A glimpse of enumerative geometry

 Message-passing algorithms for graphical models

 Canonical form of tensor networks in one and two dimensions

 The basics of topological band theory

 Building something from nothing: a mathematical framework for aperiodic/amorphous sets

 Planetary lightning: Current State-of-the-art and outstanding questions

 Collective Power of Science ~ from the High-Energy Atmospheric Physics to our New Exploration of the Universe ~

 Morse theory and Floer theory

 Knot theory and topological semimetals

 On Dark Matter