Person of the Week
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2025-06-12
Person of the Week
Self-introduction: Keiya Hirashima
Hi! My name is Keiya Hirashima, and I am a Special Postdoctoral Researcher at iTHEMS, working on galaxy formation and evolution using AI and large-scale simulations. My research focuses on modeling the effects of individual stars and stellar feedback in high-resolution galaxy simulations. To reduce computational costs, I have developed AI-based surrogate models that efficiently replace expensive physical simulations. I’m particularly interested in connecting different physical scales to study the hierarchical evolution of galaxies and the universe through numerical methods, deep learning, and high-performance computing. I also explore how fractal structures and foundation models can help extract general representations from complex physical systems. [My academic history] I began my position as a Special Postdoctoral Researcher at iTHEMS in April 2025. Prior to that, I studied computer science and mathematical science at Kyoto University in March 2020, and received my Ph.D. in Astronomy (sub: Information Science) from the University of Tokyo in March 2025. I have also worked on research on deep foundation models for (astro)physics at PolymathicAI and Flatiron Institute (USA).
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2025-06-12
Person of the Week
Self-introduction: Robert Baird
Hi, I'm Robert Baird. I'm from the UK and completed my undergraduate degree Zoology at the University of Sheffield, followed by a Masters in Biology at LMU Munich in Germany. I then completed my PhD in Evolutionary Biology at the University of Edinburgh. I'm currently a postdoctoral scientist at the Whitehead Institute for Biomedical Science at MIT, where I combine cytology with evolution to understand species with unusual genetics and what this can tell us about more fundamental biological questions. I am a visiting researcher at iTHEMS, working with Thomas Hitchcock to try to develop ideas and predictions for how some of the unusual genetic systems that I study evolved.
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2025-06-04
Person of the Week
Self-introduction: Antoine Diez
Hello! I am interested in the mathematical modeling of large scale self-organized phe- nomena in life science, from the dynamics of biological cells forming tissues to the behaviour of interacting agents within societies. These systems, often referred to as complex systems, are typically described as large systems of active particles. Their understanding mostly relies on the derivation and analysis of suitable scaling limits that reveal more informative statistical descriptors. My background is in mathematical kinetic theory, a branch of statistical physics originally developed to bridge the gap between molecular-level gas dynamics and macroscopic thermodynamic and fluid equations. My work combines analytical approaches (in particular partial differential equations, stochastic analysis and a bit of geometry) but also in silico computer simulations that are nowdays essential. I am interested in theoretical mathematical problems but I also work in close collaboration with biologists on interdisciplinary applied projects, especially in developmental biology.
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2025-06-04
Person of the Week
Self-introduction: Unashish Mondal
Hey everyone, I’m Unashish Mondal. I joined iTHEMS and the Prediction Science Research Team as a postdoctoral researcher, with a strong interest in extreme weather events and their underlying dynamics. My research primarily focuses on understanding and predicting lightning, thunderstorms, and associated hazards across the Indian subcontinent, using a combination of satellite observations, reanalysis data, and advanced modelling techniques. I’ve also worked extensively with the Weather Research and Forecasting (WRF) model to simulate cloudbursts, hailstorms, and heatwaves over India, integrating high-resolution simulations with observational analysis. I’m passionate about advancing the prediction of extreme events through data assimilation, machine learning, and high-resolution modelling—especially in data-sparse and climate-vulnerable regions. Outside of research, I enjoy reading books, traveling, and discussing philosophy and culture.
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2025-05-30
Person of the Week
Self-introduction: Vladimir Sosnilo
Hi all, my name is Vladimir (Vova) Sosnilo. I am a mathematician working in the fields of category theory, homotopy theory, and algebraic geometry. Category theory studies abstract relations between mathematical objects. In a precise mathematical sense, the Yoneda Lemma asserts that a given (mathematical) object is determined by its relations to other objects. While this means that any mathematical phenomenon can, in principle, be understood from the perspective of category theory, these relations can be incredibly intricate. The main idea unifying most of my work is the existence of simple categorical patterns that show up across many different areas of mathematics. This can be used to understand concrete objects in geometry and representation theory. I am originally from Saint Petersburg, Russia, but I also spent a significant amount of time in Germany before coming to iTHEMS. In particular, I did a three-year postdoc at the University of Regensburg. Beyond research, I am interested in music and arts. You can find more about me on my webpage or by talking to me!
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2025-05-26
Person of the Week
Self-introduction: Chi-Kang Chang
My research field is algebraic geometry, with a particular focus on birational geometry. Before joining RIKEN iTHEMS, I was a postdoctoral researcher at the National Center for Theoretical Sciences (NCTS) in Taiwan for about nine months. I completed all of my undergraduate, master's, and doctoral studies in the Department of Mathematics at National Taiwan University. During my doctoral studies, I also spent about 14 months as a visiting research associate at the Graduate School of Mathematical Sciences, the University of Tokyo.
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2025-05-14
Person of the Week
Self-introduction: Shuntaro Aoki
Hello, My name is Shuntaro Aoki, and I am a researcher at RIKEN iTHEMS. My primary areas of expertise are particle physics and cosmology, with a special focus on the early universe. I obtained my PhD from Waseda University in 2018 and worked as a lecturer at the same institution until March 2021. In April 2021, I joined Chung-Ang University in Korea, where I worked until August 2022. Subsequently, I continued my research at the Institute for Basic Science (Korea) until November 2024, before joining RIKEN iTHEMS in December 2024. My current research focuses on the cosmological collider program, which aims to uncover new physics beyond the Standard Model through the study of non-Gaussianity in primordial perturbations. These perturbations, believed to have been generated in the early universe at extremely high energies, provide valuable insights into heavy particles that are inaccessible in terrestrial experiments. Specifically, I have been working on the theoretical aspects of the cosmological collider, such as deriving analytic expressions for correlation functions and exploring particle physics models that predict large "signals" of interest. This research lies at the intersection of cosmology and particle physics, offering exciting implications for both fields. My long-term goal is to contribute to uncovering high-energy physics through cosmological observations. Ultimately, I aim to deepen our understanding of the universe's fundamental nature and its origins, while fostering new methodologies and collaborative efforts to advance the field. Beyond research, I enjoy football, fishing, and walking—activities that help me maintain a balanced and creative approach to problem-solving.
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2025-05-14
Person of the Week
Self-introduction: Iao-Fai Io
Hello everyone, my name is Iao-Fai Io, you can call me Jacky (my nickname). I am a Ph.D. student at National Taiwan University (NTU) and also an IPA student at RIKEN iTHEMS. Although I study in Taiwan, I am originally from Macau, so I know how to speak cantonese and mandarin My research direction is condensed matter physics, specifically focusing on non-Hermitian systems, particularly one-dimensional lattice models (e.g., the SSH model and its extended versions). Currently, I am studying conformal symmetry in 1+1D non-Hermitian systems, including both lattice models and field theory, to understand the differences between Hermitian and non-Hermitian cases and to explore new physics in non-Hermitian systems. I am also interested in other topics in condensed matter theory, including topological insulators and superconductors.
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2025-05-13
Person of the Week
Self-introduction: Daichi Takeda
My name is Daichi Takeda. I was born in Himeji (Hyōgo Prefecture), and have also lived in Fujisawa (Kanagawa) and Kyoto (Kyoto). I spent nine years at Kyoto University — from my undergraduate studies through my doctoral program — and received a Ph.D. in Science in March 2024. My field is theoretical high energy physics, with a focus on exploring the microscopic theory of gravity. Recently, I have been investigating the properties of black holes and methods for conducting virtual gravity experiments in a laboratory setting, with the help of the holographic principle.
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2025-05-13
Person of the WeekSelf-introduction: Dorothy Ellis
Hello! I'm Dorothy Ellis. I received my PhD in biostatistics from the University of Florida in August 2023 and joined the Laboratory for Integrative Genomics at RIKEN IMS in October 2023 as a postdoctoral researcher. I was concurrently appointed to iTHEMS in May 2025. My primary research interest is in developing machine learning and data analysis methods (especially unsupervised analysis methods) for multi-omics data.
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2025-04-03
Person of the Week
Self-introduction: Erik Loetstedt
I have a PhD in theoretical physics from Heidelberg University and have worked at the Max Planck Institute for Nuclear Physics, Missouri University of Science and Technology and The University of Tokyo before coming to RIKEN. I am interested in time-dependent problems in quantum mechanics, in particular strong field-molecule interaction. I am also interested in the simulation of quantum dynamics of molecules by quantum computers.
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2024-12-04
Person of the Week
Self-introduction: Qianteng Zhu
I am a Ph.D. student from Shanghai Jiao Tong University, China and I joined iTHEMS in Dec 2024 as an IPA student. I am interested in Lattice QCD and Machine Learning. I am studying methods to figure out hadron interactions from Lattice QCD. I am also excited to apply machine learning to physics problems. Please feel free to discuss with me.
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2024-11-18
Person of the Week
Self-introduction: Daeho Park
I interested in ameliorating methodologies employed hadron physics, especially quark model and lattice QCD, to test various ideas accurately and reliably. Then, equipped with correct characteristics of hadrons, I will trace back to QCD to investigate origin of diverse existence of hadrons. I like to combine different things in different ways, so if you have some geek-looking idea, please let me know!
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2024-10-11
Person of the Week
Self-introduction: Yuuka Kanakubo
Hi, I’m Yuuka. I did my PhD at Sophia University in Japan, and moved to Finland and spent 2 years there as a postdoc at the University of Jyväskylä. Now, I have returned to Japan as a RIKEN-Berkeley fellow at iTHEMS. Since my PhD, I have been working on the development of Monte-Carlo event generators for relativistic nuclear collisions. I am generally interested in a collision of large and heavy nuclei, such as lead ions or gold ions, with a large mass number. The typical collision energy reaches up to a few TeV per nucleon pair at their centre of mass. With these experimental setups, we can generate an extremely hot soup of quarks and gluons, known as “quark-gluon plasma”. Relativistic nuclear collisions are dynamical processes with several different stages. I describe the collision process in full 3D and as dynamically as possible by sequentially applying different theoretical descriptions to each stage. For instance, I describe the production of quarks and gluons in the initial impact of colliding nuclei using perturbative QCD, the evolution of quark-gluon plasma with relativistic relativistic hydrodynamics combined with lattice QCD, and the interaction of hadrons in the final state using hadronic transport. I believe iTHEMS is an excellent research environment in this aspect as the study requires diverse knowledge in, for example, nuclear structure, perturbative and non-perturbative QCD, thermodynamics, methodology in Monte-Carlo simulations of many-body systems etc. I am excited to discuss with people from various fields and hope to find new solutions or new ideas!
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2024-10-07
Person of the Week
Self-introduction: Gabriele Di Ubaldo
I am broadly interested in understanding quantum gravity as an emergent phenomenon. This is the case in the AdS/CFT correspondence where a d+1-dimensional theory of quantum gravity (usually a string theory) emerges from the collective dynamics of a d-dimensional Conformal Field Theory (CFT) with many degrees of freedom. I believe this is a beautiful example of Anderson's principle "More is different", where many-body quantum systems (the CFT) can exhibit striking and unexpected collective behaviour (Gravity). I am particularly interested in the role of quantum chaos and thermalization in the correspondence between CFT and black hole physics and how to explain and derive gravitational phenomena, such as wormholes, using CFT and the tools of the conformal bootstrap. More broadly, I am interested in many-body quantum systems, disordered systems, classical and quantum chaos, and diverse topics in math, such as random matrix theory, analytic number theory (modular forms), topological recursion, and three-manifold geometry. If you are working on any of these topics or are simply interested, I'll be happy to talk physics! Previously, I obtained my PhD at the Institut de Physique Theorique in Paris, CEA Saclay, working with Eric Perlmutter, and my master's degree at Ecole Normale Superieure in Paris. Looking forward to my time at RIKEN and UC Berkeley!
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2024-10-03
Person of the Week
Self-introduction: Xiaoyang Wang
My main research interests focus on the cross of quantum computation and many-body systems, in particular, the near-term quantum algorithm for lattice field theory, spin models, and combinatorial optimization problems. We intend to demonstrate the advantage of quantum computers in real-world applications on currently available quantum devices.
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2024-04-09
Person of the Week
Self-introduction: Sonia Mahmoudi
Bridging the worlds of mathematics and materials science, I am interested in exploring the fascinating interactions between the topology of entangled structures and their mechanical properties. With an interdisciplinary and international background spanning mathematics, design, and engineering, I have explored various industries before transitioning to an academic career. My doctoral journey at Tohoku University focused on low-dimensional topology in woven structures, laying the foundation for my current work with SUURI-COOL Sendai. My research primarily focuses on the topological classification of periodic entangled structures from the viewpoint of knot theory and is oriented toward potential applications in academia and industry. These structures, found in a wide range of materials from textiles to molecular assemblies, exhibit remarkable properties such as elasticity, auxetic behavior, and self-folding capabilities, which are predominantly dictated by their entanglement complexity rather than the constituent materials themselves. I believe that mathematics is the key to unveiling these structure-function relations. As part of the iTHEMS community, I hope to collaborate, innovate, and contribute to the creation of new mathematical theories that could eventually support the design of sustainable and innovative materials and systems. I look forward to discussing new scientific discoveries in entangled structures with many of you.
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2024-03-11
Person of the Week
Self-introduction: Lingxiao Wang
Hello everyone! My name is Lingxiao Wang (王 凌霄). My research ambitiously bridges the fields of machine learning and physics, with a particular focus on using deep learning techniques, such as deep neural networks (DNNs) and generative AI, to explore QCD matter with physics models and lattice calculations. Beyond traditional boundaries, my work extends to pioneering applications of AI for Science, such as the automating scientific discovery, medical AI, and the analysis of collective behavior. My academic journey in physics commenced with a Ph.D. at Tsinghua University, China(2015-2020), where I investigated quark matter under extreme conditions. Concurrently, I was a visiting Ph.D. student at the University of Tokyo, Japan(2018-2019), focusing on chiral matter. During my postdoctoral position at the Frankfurt Institute for Advanced Studies(FIAS), Germany (2020-2023), I honed my expertise in applying machine learning to physical sciences, and simultaneously held a joint position as a Research Assistant at Insitute of Physics in Goethe University, where I applied machine learning to THz physics. Currently, I am also a Visiting Scholar at the Institute of Modern Physics, Fudan University, China, working on machine learning applications in particle and nuclear physics. For many years, I have organized a series of "Machine Learning Physics" seminars and learning clubs, providing an inclusive space for scientists interested in AI. I am especially enthusiastic about knowledge sharing and discussions that pave the way for interdisciplinary topics. My door (Main Building 249) is always open for anyone who wants to drink a cup of coffee/tea with me!
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2024-01-17
Person of the Week
Self-introduction: Camilia Demidem
My field of research is high-energy astrophysics. The fundamental open questions that motivate my work are that of the origins of high-energy cosmic rays and the nature of the physical processes dissipating energy in extreme astrophysical environments such as active galactic nuclei, gamma ray bursts or pulsar wind nebulae. More specifically, I investigate the multi-scale physics of shocks, turbulence and particle acceleration possibly at play in these environments using theoretical modelling and different numerical frameworks, including particle-in-cell and magnetohydrodynamic simulations. I am excited to join a group of scientists from such diverse backgrounds and I am particularly looking forward to working alongside researchers in the fields of health and biology for the first time! I am also eager to improve my Japanese, よかったら、日本語で声を掛けてください！
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2023-12-11
Person of the Week
Self-introduction: Pratik Nandy
I am Pratik Nandy, a theoretical physicist from India. After graduating from the Indian Institute of Science, Bangalore, in 2022, I moved to the Yukawa Institute for Theoretical Physics (YITP), Kyoto University, as a postdoctoral researcher in the Extreme Universe Collaboration (ExU). I joined iTHEMS in November 2023. My research interests include understanding quantum chaos in holography and condensed matter physics by using various quantum information theoretic quantities, such as entanglement and complexity. Recently, I have been working on the formulation of quantum chaos in dissipative systems and quantum field theories, especially systems with holographic duals, such as Sachdev-Ye-Kitaev (SYK) models and their double-scaled variations. I believe these systems can teach us important lessons about the quantum nature of gravity in de Sitter (dS) and Anti-de Sitter (AdS) space. I am based at the SUURI-COOL, Kyoto University campus, where I am also affiliated with the YITP. I regularly visit the Wako campus and look forward to discussions with various experts from interdisciplinary environments. I will be happy to assist you if you plan to visit SUURI-COOL, Kyoto.
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2023-11-16
Person of the Week
Self-introduction: Dongwook Ghim
I am a theoretical physicist working on high-energy physics, HEP-TH. More precisely, I am interested in the spectral problems of strongly coupled gauge theory. The infamous quark confinement of Quantum Chromodynamics and the mass gap generation of Yang-Mills theory are the most well-known spectral problems involving strongly coupled gauge theory. I mainly use two orthogonal toolkits to tackle such problems; supersymmetry and quantum simulation. I have worked on the computation of the twisted partition function of supersymmetric gauge theories, which appear in the string theory context, showing a strong relation with the geometry of Calabi-Yau manifolds. Simultaneously, I am eager to develop a quantum algorithm that can capture the spectra of gauge theories, without the aid of supersymmetry. The latter targets low-dimensional lattice gauge theory in practice. But I dream of capturing the physics of three- or four-dimensional gauge theory on the quantum processor near future. I look forward to a fruitful collaboration with people in iTHEMS, RIKEN.
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2023-10-06
Person of the Week
Self-introduction: Yuto Yamamoto
I specialize in tropical geometry, a field of mathematics that naturally emerges when considering the limits of spaces with respect to some parameters. My primary research interest lies in calculating the limits of invariants of the spaces using tropical geometry. Despite being a relatively new field, tropical geometry has already demonstrated its applicability to other various sciences. During my time at iTHEMS, I look forward to exploring such applicational aspects of tropical geometry as well.
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2023-10-06
Person of the Week
Self-introduction: Misako Tatsuuma
I'm Misako Tatsuuma, and I joined iTHEMS as a Research Scientist in October 2023. My research focuses on planetary formation theory. Specifically, I'm working on the formation process of planetesimals, which are kilometer-sized bodies like comets and asteroids, from micron-sized cosmic dust grains. This process is still not fully understood and has been extensively studied through observations, explorations, experiments, and simulations. My approach involves investigating the material strengths of dust aggregates using dust grain N-body simulations and comparing the results with explorational findings of comets and asteroids in our solar system. I got my Ph.D. in March 2022 at the University of Tokyo and subsequently began the JSPS fellow (PD) at Tokyo Institute of Technology. As for personal, I'm a mother of two and facing the ongoing challenge of balancing childcare and research.
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2023-10-05
Person of the Week
Self-introduction: Shinichiro Fujii
My name is Shinichiro Fujii. I was originally a nuclear theorist. After finishing my PhD at Kyushu University in 2000, I joined RIKEN as a special postdoctral researcher. After that, I had several positions including associate professor at the University of Tokyo. After a period of unemployment at the age of 40 due to the term limit, I was hired by JST-CRDS as a fellow in 2013. I conducted research and survey activities to formulate Japan's science and technology policy for 5 years. After that, I was involved in the management of large national projects related to quantum computers and quantum communications, such as JST-ERATO, Q-LEAP and Moonshot Goal 6, at the University of Tokyo and Yokohama National University for 5 years. 23 years after beginning my career as a researcher at RIKEN, I am back to RIKEN as a coordinator in 2023. I would like to contribute to creating a better environment for researchers and enhancing the value of RIKEN.
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2023-08-02
Person of the Week
Self-introduction: Yuta Sekino (2023)
I am Yuta Sekino. After finishing my Ph. D at Tokyo Institute of Technology in 2019, I worked in RIKEN as a JSPS Postdoctoral Fellow (2019-21) and Postdoctoral Researcher in ABBL (2021-23). During 2021-2023, I also belonged to iTHEMS as a concurrent member. In July 2023, I officially joined iTHEMS as a Postdoctoral Researcher associated with RIKEN Quantum. I am a theoretical condensed-matter physicist mainly working on ultracold atomic systems. My main research interest is superfluidity, superconductivity, and spin transport. Because these phenomena have been widely discussed not only in condensed-matter physics but also in nuclear physics and astrophysics, I would like to collaborate with iTHEMS researchers working in these fields. As a member of RIKEN Quantum, I also would like to apply quantum computational methods to nonequilibrium phenomena such as post-quench dynamics in quantum spin systems. Because quantum computing would have the potential to tackle unsolved problems in every field of science, I would be happy to have interdisciplinary discussions in RIKEN Quantum. At iTHEMS, I hope to broaden my research horizon through discussions with researchers in various fields.
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2023-08-02
Person of the Week
Self-introduction: Steffen Backes
Hello! My name is Steffen Backes, and I just joined RIKEN Quantum as a Senior Scientific Researcher. My research interest is focused on the physics and phenomena that can be found in strongly correlated electron systems, such as transition metal oxides, cuprate and iron-based superconductors, nickelate materials, or other low-dimensional lattice systems. In these systems the Coulomb repulsion between electrons gives rise to unexpected emergent phenomena such as magnetism, charge order, superconductivity, the metal-to-insulator transition, changes in their optical properties, and many more. My particular interest lies in going beyond an effective single-particle description of the electronic system, using perturbative and non-perturbative methods. For this, I am employing the GW approximation, Dynamical mean-field theory and its extensions such as cluster methods, or combinations in the form of GW+DMFT. In iTHEMS I will investigating how current Quantum processors, or "Noisy Intermediate Scale Quantum" (NISQ) devices can be used to solve the problems we encounter when studying such correlated electron systems with state-of-the-art numerical methods. Since these devices are inherently noisy, the development of fault-tolerant algorithms is one of my major goals.
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2023-08-02
Person of the Week
Self-introduction: Yaokun Lei
My name is YaoKun Lei, and I joined iTHEMS in August 2023. I am originally from a city in the south of China. After finishing my undergraduate studies, I pursued a Ph.D. at Peking University, where I focused on studying the significant role of dynamic solvent effects in chemical reactions in condensed phases using enhanced sampling methods. Upon completing my Ph.D., I became a visiting scholar at the ShenZhen Bay Laboratory. During this period, I developed efficient strategies for rare event sampling and reaction coordinate analysis without prior knowledge of the reaction mechanism, using Reinforcement Learning and likelihood maximization techniques. In July 2021, I joined Theoretic Molecular Science Laboratory at RIKEN. Over the past two years, my research has been centered around developing accurate, efficient, and transferable machine learning force fields for systems embedded in external potentials, with the aim of accelerating QM/MM simulations using multi-scale equivariant graph convolution networks. Looking ahead, I am enthusiastic about leveraging quantum computing to accelerate large-scale molecular dynamics simulations. Specifically, I plan to utilize high-precision quantum computational results to expedite the parameterization of machine learning force fields. Additionally, I aim to enhance sampling in high-dimensional spaces through quantum computing. During my time at iTHEMS, I hope to have the opportunity to collaborate with researchers from different disciplines and embark on exciting new explorations.
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2023-07-03
Person of the Week
Self-introduction: Jan Schuette-Engel
Hello, I’m Jan and I work on theoretical high energy particle physics, astroparticle physics and cosmology. I’m based at UC Berkeley. My work focuses on probing high energy particle physics with gravitational waves (GWs). Additionally, I develop novel ideas for earth based experiments to discover new physics.
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2023-06-06
Person of the Week
Self-introduction: Derek Beattie Inman
Hello! My name is Derek Inman, and I am a scientist at iTHEMS whose research is focused on cosmology. Our Universe contains a substantial amount of dark matter the behavior of which we broadly know, but the composition of which we don’t. I try to understand how different ideas for what dark matter is (particles? black holes? something else?) change how the Universe looks and evolves at various times and length scales. I am particularly interested in cosmological structure formation, which rapidly becomes a nonlinear problem and so I tend to use numerical simulations run on supercomputers to understand the relevant physics.
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2023-05-11
Person of the Week
Self-introduction: Kohei Hayashi
Hi, my name is Kohei Hayashi. I am a visiting researcher as the postdoctral fellowship of Japan Society for the Promotion of Science (JSPS). So far, I have been working on explaining macroscopic behavior of some physical quantities from microscopic models. Especially, my interest lies in universality that arises in fluctuations of Markov processes. An important example of such universality class is the Kardar-Parisi-Zhang universality class and it has been observed in various probabilistic models. I am trying to understand mechanisms or backgrounds of such universality in mathematically rigorous ways.
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2023-04-28
Person of the Week
Self-introduction: Rongyang Sun
My name is Rongyang Sun. I joined RIKEN in October 2021 as a Postdoctoral Researcher in R-CCS and RQC. Now, I am very glad to hold this concurrent position in iTHEMS. As a full-stack researcher in computational quantum many-body physics, my ultimate goal is to understand the fantabulous nature of quantum many-body systems by taking advantage of modern supercomputing systems and quantum computers. Towards this goal, I am developing advanced tensor network algorithms, maintaining high-performance tensor computing software, and applying these tools to the study of strongly correlated systems like interacting electrons and frustrated spins. Meanwhile, I am also exploring the possibility of utilizing near-term quantum computers to arrive at the same destination.
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2023-04-28
Person of the Week
Self-introduction: Tomonori Shirakawa
My name is Tomonori Shirakawa. I joined iTHEMS as a Senior Research Scientist in April 2023. I am interested in quantum many-body phenomena in condensed matter physics. To better understand quantum many-body phenomena, I have been working with various numerical methods. In particular, I have recently been exploring more efficient ways to solve quantum many-body problems using quantum-classical hybrid algorithms, quantum algorithms, and tensor network methods.
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2023-04-10
Person of the WeekSelf-introduction: Seishiro Ono
My name is Seishiro Ono. I received my Ph.D. from the University of Tokyo in March 2023, and then I joined RIKEN iTHEMS in April 2023. My research interests lie in quantum condensed matter physics. I have been fascinated by the diversity of this field, and I am eager to understand the various phenomena from a unified point of view. I am currently investigating a unified understanding of superconductivity based on symmetry and topology. In addition, I have recently become interested in experimental signatures of topological nature, applications of machine learning to materials science, and quantum simulation of strongly correlated systems.
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2023-04-07
Person of the Week
Self-introduction: Zixia Wei
My name is Zixia Wei, and I got my Ph.D. from Yukawa Institute, Kyoto University in March 2023. I work on many different aspects of the AdS/CFT correspondence. The AdS/CFT correspondence relates a gravitational theory to a non-gravitational theory in a lower-dimensional system. Recently, I am interested in studying statistical physics with the help of the AdS/CFT correspondence. Thermal states in non-gravitational systems, which are often the targets of statistical physics, are related to black holes via the AdS/CFT correspondence. Obvious observations in black holes are sometimes nontrivial when translated back to statistical systems. I am working on making nontrivial conjectures in general statistical systems by considering black holes and then trying to prove them back in statistical systems.
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2023-04-06
Person of the Week
Self-introduction: Che-Yu Chen
Hi, my name is Che-Yu Chen, a Taiwanese researcher, joining RIKEN iTHEMS as an SPDR in April 2023. I got my Ph.D. in Physics from National Taiwan University in 2019. After my graduation, I stayed as a postdoc at LeCosPA-NTU (2019-2020) and then became an AS postdoc at the Institute of Physics, Academia Sinica (2020-2023), before coming to RIKEN. My interest is mainly in gravitational physics, including modified gravity and the phenomenological aspects of quantum gravity. In particular, I'm currently working on using state-of-the-art black hole observations to test general relativity (GR), or even to probe putative non-GR physics. The direct detection of gravitational waves emitted from binary black hole mergers, and the images of supermassive black holes, have ushered in a completely new era in which directly probing spacetimes near black holes becomes possible. There are several interesting non-GR physics, some of which could even be motivated by quantum gravitational effects. These non-GR physics could induce non-trivial or even unique imprints on gravitational waveforms and black hole images, and hence can possibly be tested in the future. A better understanding of this topic can tell us how well GR describes such extreme spacetime regimes, and if it were to be modified, which direction is more observationally preferred. I'm looking forward to the fruitful discussions with the iTHEMS members in the future.
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2023-04-05
Person of the Week
Self-introduction: Tomoya Nagai
My name is Tomoya Nagai. I joined as a coordinator in April 2023. I started working after getting the Ph.D. in astrophysics and have worked in science communication, R&D strategy development, research funding and R&D management. Until March 2023, I worked at KEK and Kobe University, where I was manager of research projects using the supercomputers “Fugaku". I will do my best to help you in your research.
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2023-04-05
Person of the Week
Self-introduction: Tingyu Zhang
My name is Tingyu Zhang, and I joined iTHEMS as a junior research associate in April 2023. Now I am involved in a PhD program in physics at the University of Tokyo. I mainly focus on the study of quantum many-body systems and non-equilibrium physics. Specifically I’m now studying the transport phenomena in cold atomic systems, through Green’s function methods and the perturbation theory. I’m looking forward to discussing physics with other researchers in the future.
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2023-02-07
Person of the Week
Self-introduction: Christian Quirouette
Hi, my name is Christian Quirouette. I am a postdoctoral fellow at Toronto Metropolitan University in Canada. My field of research is virophyiscs, i.e. applying methods of physics to problems in virology. My research primarily focuses on stochastic mathematical modelling of viral infections. I’m excited to be working here at iTHEMS and have the chance to discuss and possibly collaborate with other researchers in other fields.
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2023-02-03
Person of the Week
Self-introduction: Liang Zhang
I’m a Ph.D. student form Shanghai Institute of Applied Physics (SINAP), Chinese Academy of Sciences (CAS). And I came to iTHEMS on January 26th, 2023. When I was a undergraduate learning nuclear physics, I’m curious about how we can calculate the interactions between nucleons. I think it is the key for us to understand nucleus better. Beside this, I also learnt that there are hypernucleuses, where several nucleons are replaced by other baryons. So, if the interactions can be calculated from quark model and QCD theory, it allows us to study not only the normal nucleuses but also hypernucleuses which may exist at the beginning of the universe. HAL QCD is a great way to study the interactions between baryons by using lattice QCD calculation. I’m so glad to have this chance to study HAL QCD in iTHEMS. I hope I can receive knowledge and friendship here.
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2022-11-02
Person of the Week
Self-introduction: Puttarak Jai-akson
My name is Puttarak Jai-akson. I hail from Thailand and I obtained my bachelor’s degree there. I then moved to Canada to join the PSI program and completed my PhD at Perimeter Institute. I joined iTHEMS in November 2022 as a postdoctoral researcher and I have been very excited to learn, share, and cultivate new ideas with fellow researchers in this interdisciplinary environment. My research mainly focuses on theoretical aspects of gravity, leaning especially towards the theme of black holes, holography, and quantum gravity. I am interested in the idea of quasi-local holography, centering around the study of gravity in finite regions of spacetime where a wealth of fascinating mathematical structures and physics is unfolded. One topic which I have been currently pursued is the underlying correspondence between gravitational physics near finite null boundaries (such as black hole horizons) and Carrollian hydrodynamics, an unusual type of fluid dynamics living at the opposite corner to the conventional Navier-Stokes fluid dynamics. This correspondence will certainly shed light on the better understanding of black holes and their thermodynamical properties. I also believe that the connection between gravity and hydrodynamics will open a new route for the grand quest to quantize gravity.
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2022-11-02
Person of the Week
Self-introduction: Maria Manuela Saez
Hola!, This is Maria Manuela Saez, an Argentinian astronomer and a new RIKEN - Berkeley postdoctoral fellow. I'm interested in astrophysics, and in particular, my research focuses on the study of core-collapse supernovae and the role that neutrinos play in these astrophysical environments. Core-collapse supernovae are the final evolutionary stage of massive stars and represent a long-awaited observation target for neutrino telescopes. To explain these events, one needs an interdisciplinary field of research that combines nuclear physics, particle physics, astrophysics and numerical simulations. Studying the signals that the supernovae' neutrino fluxes leave in the detectors, with an appropriate neutrino flavor discrimination, is possible to infer properties of the physics of the neutrinos involved and to study scenarios with non-standard neutrino properties. The structure of the neutrino mass spectrum and lepton mixing is imprinted into the detected signal. My goal is to contribute, from a theoretical perspective to the definition of strategies for detecting and studying neutrinos in large underground neutrino and dark matter detectors. I'm looking forward to discussing and collaborating with iTHEMS people.
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2022-11-02
Person of the Week
Self-introduction: Ermal Rrapaj
Hi, my name is Ermal Rrapaj, and I am a new RIKEN-Berkeley fellow. My research centers on the intersection of quantum many body physics and astrophysics. The general focus is on how particle interactions affect the properties of extreme environments such as supernovae and neutron stars and how they relate to earth experiments. The main research topics include properties of nuclei that could be tested in future experiments, neutrino nucleon matter interactions, transport properties of neutron stars, supernovae equation of state, and astrophysical implications from BSM particles. In recent years Ermal has been exploring how new technologies such as machine learning (neural networks) and quantum computing can aid in these research venues.
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2022-11-01
Person of the Week
Self-introduction: Thomas Hitchcock
Hi, I’m Thomas Hitchcock. I grew up in the UK, studying Genetics and Systems Biology at the University of Cambridge, before moving up to the University of St Andrews to do my PhD in Evolutionary Genetics, and have now joined iTHEMS as an SPDR. I’m interested in why organisms appear the way they do, and how we can use evolutionary theory to better understand this. In practice, I’ve study two main flavours of problem, (1) when and why do organisms (and genes) come into conflict with one another, and (2) how are organisms (and genes) expected to weight different fitness trade-offs. To tackle these problems, I use a mix of population genetics and evolutionary game theory, and focus mainly on unusual genetic systems, life histories, and ecologies, which I hope might prove particularly clear tests of theory. I’m excited to discuss and learn from the wide variety of researchers at iTHEMS, and hopefully incorporate some new mathematical tools and frameworks into ecology and evolution.
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2022-07-04
Person of the Week
Self-introduction: Christy Kelly
Hi, I'm Christy Kelly. I studied physics for my undergraduate degree in London before moving to Edinburgh to do a PhD in theoretical physics at Heriot-Watt university, completed in early 2022. I have now joined iTHEMS as an SPDR. I am interested in gravity, especially coarse aspects of gravity that persist in the absence of differentiable structure; in more physical terms, we can perhaps think of this as gravity in regimes where quantum fluctuations become significant. In such regimes, basic mathematical tools such as calculus are no longer valid and it becomes nontrivial how to characterise even such fundamental notions as curvature. To get around this problem, I hope to exploit the recently flourishing mathematical field of optimal transport theory, which has already become a paradigm for the study of low regularity Riemannian geometry and has seen some very exciting recent developments in the Lorentzian case. Unexpected connections to different fields of physics also arise naturally in the optimal transport theoretic framework: for instance, the Einstein equations can be characterised in terms of the convexity/concavity properties of certain entropy functionals along choice trajectories in spacetime. Optimal transport theory also provides a notion of curvature for networks which has proved of some structural significance; I hope to also take this line of research forward during my time here at iTHEMS.
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2022-06-09
Person of the Week
Self-introduction: Akira Matsumoto
I am Akira Matsumoto. I was in KEK until March 2022 as a student of SOKENDAI and got my Ph.D. there. Then I came to RIKEN and joined iTHEMS as a postdoctoral researcher in May 2022. I am interested in non-perturbative nature of gauge theories such as quantum chromodynamics (QCD), which describes the dynamics of quarks and gluons. Since these elementary particles are building blocks of matter, QCD is the important key to understanding history of our universe. The most powerful method of studying QCD is the Monte Carlo simulation based on the lattice gauge theory. So, we can simulate the dynamics of QCD on a supercomputer. However, in some cases, the Monte Carlo method is not applicable due to the so-called sign problem. For example, QCD with the chemical potential or with the topological theta term suffer from this problem. Since they are related to the structure of neutron star and the strong CP problem, the sign problem is a major obstacle to understanding such phenomena. I am studying and developing methods to avoid this problem. There are some conventional approaches such as the complex Langevin method and the tensor renormalization group. I am also trying to apply recently developing quantum computation to the simulation of gauge theories. I expect we can overcome the sign problem by using these methods in near future.
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2022-04-20
Person of the Week
Self-introduction: José Said Gutiérrez-Ortega
¡Hola! This is José (ホセ). I am a Mexican biologist in search of knowledge and interactions with scientists in all disciplines. I obtained my bachelor's degree in Mexico and completed my graduate studies in Japan: two countries where I grew up as a researcher, and where I also had great experiences working in science education. I joined iTHEMS as a SPDR in April 2022, and this transition represented an extraordinary chance for me to expand my research lines and interests. My scientific background is in evolutionary biology and ecology. Therefore, the main questions that motivate my studies are “how is the origin of the species?”, “why are species the way they are?”, “why do species change over time?”, “how do species interact with the environment and other species?”. To answer that kind of questions, I have gained abilities in phylogenetics, phylogeography, population genetics, plant systematics, botany, taxonomy, and population ecology. If these prior skills are useful for your research, or if you want to start something completely new, I am always available to work together with you. よろしくおねがいします！
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2022-04-18
Person of the Week
Self-introduction: Yuto Moriwaki
Quantum field theory is a physical theory that describes a wide range of phenomena from the subatomic world to the cosmic scale, and can be regarded as a fruit of human wisdom. However, quantum field theory has not yet been mathematically formulated. This problem perhaps asks us, "How do we formulate space?" According to the philosophy of algebraic geometry, "space and algebra" are almost the same thing. Here, the algebra is a collection of functions (classical fields). So let us consider the algebra consisting of quantum fields. The "classical algebra" is associative, whereas the "quantum algebra" is non-associative. What should be the corresponding space? I am currently studying this algebra of quantum fields in the case of two-dimensional quantum field theory. In my previous research, I have worked mathematically on (1) a formulation of the algebra of two-dimensional conformal field theory, (2) constructions of examples, and (3) a construction of non-perturbative deformations. More recently, I have returned to the question of "space" a bit, studying the axioms (consistency) of quantum field theory from a viewpoint of an operad structure of moduli spaces and higher categories. I was originally a pure mathematician studying representation theory. Crossing the field into physics has been fruitful for my life, although there is still a lot I don't understand. I am very happy to be here at iTHEMS and hope to have good interactions and co-evolution with many researchers.
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2022-04-15
Person of the Week
Self-introduction: Shou Yoshikawa
My name is Shou Yoshikawa. I joined RIKEN iTHEMS as an SPDR in April 2022. I am a mathematician studying algebraic geometry. I am interested in an analog of the existence of Kähler-Einstein metric to positive characteristic. Algebraic geometry in positive characteristic is a purely mathematical subject, however, the Einstein metric is deeply related to Physics. I hope that we find a new relation between mathematics and other sciences studying such analogies.
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2022-04-15
Person of the Week
Self-introduction: Daiki Kumakura
My name is Daiki Kumakura. I joined iTHEMS as JRA (Junior Research Associate) in April 2022. My research fields are microbial evolutionary ecology and mathematical biology. Still undergraduate, I researched the metabolism of deep marine microbes with transcriptome analysis and comparative genome analysis. Because I am interested in the evolutionary process of microbes with the ecological interactions, I currently have researched the coevolution of microbes with theoretical analysis. Then, I do interdisciplinary research of fieldwork and theoretical simulation. The main field is a hot spring (Japanese is an onsen). I sample the sediments and water at each location and do bioinformatics. In the theoretical analysis, I construct mathematical modeling and simulation. I have the unique experience of discussing with theoretical researchers in various fields at iTHEMS. Through this interdisciplinary research and discussion, I hope to make my doctoral course meaningful.
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2022-04-15
Person of the Week
Self-introduction: Taketo Sano
My name is Taketo Sano. I joined iTHEMS as a special postdoctoral researcher in April 2022 after I got the Ph.D. in mathematical sciences from the University of Tokyo. My research area is in low-dimensional topology and knot theory. I am interested in the intersection of (or interaction between) topology and combinatorics. Spaces are inherently infinite and beyond direct computations, while their algebraic images (under some nice mappings) are usually more tractable, and in some cases algorithmically computable. When one finds nice properties in the algebraic level, it is natural to expect that they are reflections of some hidden structures in the spacial level. My aim is to investigate the nature of the unseeable spaces through their algebraic images, by using theoretical tools (from algebraic topology, homotopy theory and category theory) together with computer powers.
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