Workshop

From Quarks to Neutron Stars: Insights from kHz gravitational waves

April 23 (Wed) - 24 (Thu), 2025

Astronomical observations of binary neutron star mergers and supernovae provide unique opportunities to explore physics spanning from quarks to neutron stars. The groundbreaking multi-messenger observation of GW170817, combining electromagnetic signals and gravitational waves, vividly demonstrated this potential. Furthermore, if a core-collapse supernova were to occur in our galaxy, it would likely become the first event where electromagnetic signals, neutrinos, and gravitational waves are detected together. The interior of neutron stars is not yet well understood due to their extreme density, where exotic states of matter may emerge. Gravitational waves, particularly in the kilohertz band, play a crucial role in extracting information about such ultra-high densities. In recent years, several concepts for kilohertz-band gravitational wave detectors, such as Australia's NEMO, have been proposed to advance multi-messenger studies of high density astrophysical objects. KAGRA in Japan is also exploring upgrades aimed at enhancing high-frequency sensitivity, which could significantly improve sky localization accuracy and enable the detection of post-merger signals. This workshop aims to explore the transformative potential of high-frequency gravitational wave observations for multi-messenger astrophysics, with a focus on their implications for nuclear and neutron star physics. The workshop aims to spark dynamic discussions and cultivate new collaborations among participants through invited talks by leading experts and engaging poster presentations.

Venue: via Zoom

Event Official Language: English

Third Workshop on Density Functional Theory: Fundamentals, Developments, and Applications (DFT2025)

March 25 (Tue) - 27 (Thu), 2025

The density functional theory (DFT) is one of the powerful methods to solve quantum many-body problems, which, in principle, gives the exact energy and density of the ground state. The accuracy of DFT is, in practice, determined by the accuracy of an energy density functional (EDF) since the exact EDF is still unknown. Currently, DFT has been used in many communities, including nuclear physics, quantum chemistry, and condensed matter physics, while the fundamental study of DFT, such as the first principle derivations of an accurate EDF and methods to calculate many observables from obtained densities and excited states, is still ongoing. However, there has been little opportunity to have interdisciplinary communication. On December 2022, we had the first workshop on this series (DFT2022) at Yukawa Institute for Theoretical Physics, Kyoto University, and several interdisciplinary discussions and collaborations were started. On February 2024, we had the second workshop on this series (DFT2024) at RIKEN Kobe Campus, and more stimulated discussion occured. To keep and extend collaborations, we organize the third workshop. Since the third workshop, we extend the scope of the workshop to the development and application of DFT as well. In this workshop, the current status and issues of each discipline will be shared towards solving these problems by meeting together among researchers in mathematics, nuclear physics, quantum chemistry, and condensed matter physics. This workshop mainly comprises lectures/seminars on cutting-edge topics and discussion, while sessions composed of contributed talks are also planned.

Venue: 8F, Integrated Innovation Building (IIB) / via Zoom

Event Official Language: English

Kyushu IAS-iTHEMS conference: Non-perturbative methods in QFT

March 10 (Mon) - 14 (Fri), 2025

The most commonly used approach in the study of QFT is perturbation theory. Indeed, we have succeeded in extracting various physical quantities from perturbative (asymptotic) expansions. However, some physical phenomena cannot be captured through perturbative analyses alone. How can we extract these non-perturbative effects? In QFTs with conformal symmetry (i.e., CFTs), correlation functions can be computed using a method called the conformal bootstrap. This non-perturbative method differs entirely from the usual correlation function analysis methods of QFT, as it does not even assume the existence of a Lagrangian. Through the use of the conformal bootstrap, we have actually made significant progress in the non-perturbative understanding of CFTs. Furthermore, according to the holographic principle, CFTs provide a non-perturbative formulation of QFTs with gravity (i.e., quantum gravity). By applying the holographic principle to various non-perturbative results from CFTs, such as those obtained from the conformal bootstrap, we have made remarkable advances in understanding the non-perturbative aspects of quantum gravity. Conversely, the holographic principle is also used to understand properties of QFTs that are difficult to analyze perturbatively, through gravity.

Venue: Kyushu University Ito Campus, Inamori Hall

Event Official Language: English

iTHEMS Cosmology Forum 3 - (P)reheating the primordial Universe

March 4 (Tue) - 5 (Wed), 2025

Seishi Enomoto (Postdoctoral Researcher, College of Engineering Science, Yokohama National University)
John T. Giblin (Professor, Department of Physics, Kenyon College, USA)
Kyohei Mukaida (Assistant Professor, Theory Center, High Energy Accelerator Research Organization (KEK))

iTHEMS Cosmology Forum Workshop is a series of short workshops, each focusing on an emerging topics in cosmology. The target audience is cosmologists, high-energy physicists and astronomers interested in learning about the subject, not just those who have already worked on the topic. The goal of the workshop is to provide working knowledge of the topic and leave dedicated time for discussions to encourage mutual interactions among participants. The third workshop is devoted to the 'reheating' phase of the early Universe. Reheating bridges the gap between the (almost) empty universe at the end of cosmic inflation and the thermal state of particles, required for Big-Bang nucleosynthesis, and the events of the hot Big-Bang model as a whole, to unfold. It is expected to proceed in different stages starting with a violent parametric resonant creation of particles, dubbed preheating, followed by a redistribution of energy leading to a thermal state. This phase potentially hosts rich phenomenology such as the formation of topoligical defects e.g. solitons, generation of gravitiational wave, and so on. Yet, the very non-linear nature of reheating makes it notoriously hard to describe analytically, and even numerical simulations struggle to follow the whole sequence of events in a given model. Reheating studies have thus yet to reach the degree of compherensiveness and universality that the understanding of cosmic inflation has achieved. This forum will consist of two events. The first, on March 4th, will be in conference format comprising scientific talks on research trends in (P)Reheating. The second, on March 5th, will be a tutorial on numerical aspects of reheating (both theory and hands-on with code) hosted by Tom Giblin of Kenyon College. The workshop will be in English. The workshops are organised by the iTHEMS Cosmology Forum working group, which is the successor of the Dark Matter Working Group at RIKEN iTHEMS. Important dates: Feb. 25th - Registration deadline March 4th - Workshop Day (Room #435-437, Main Research Building 4F) March 5th - Tutorial Day (Room #445-447, Main Research Building 4F) Invited Speakers: John T. Giblin - Kenyon College Kyohei Mukaida - KEK Seishi Enomoto - Yokohama National University Organisers: Kohei Hayashi, Nagisa Hiroshima, Derek Inman, Amaury Micheli, Ryo Namba

Venue: #435-437, 4F, Main Research Building / #445-447, 4F, Main Research Building

Event Official Language: English

RIKEN-Nara Women's University Joint Diversity Promotion Workshop 2025

March 3 (Mon) - 4 (Tue), 2025

The RIKEN Interdisciplinary Theoretical and Mathematical Sciences Program (iTHEMS) and the Faculty of Science at Nara Women's University are promoting a project to foster female researchers under the auspices of the RIKEN Diversity Promotion Office. As part of the program, 19 undergraduate and graduate students from Nara Women's University will visit several laboratories on the RIKEN Wako campus to ask questions about their research and hold workshops/presentations with iTHEMS researchers. Organizers: RIKEN Interdisciplinary Theoretical and Mathematical Sciences Program (iTHEMS) Faculty of Science, Nara Women's University Program: 13:50-15:15 RIBF Facility, RIKEN Nishina Center (RNC) (E01, Nishina RIBF Building) 15:30-16:30 RIKEN Interdisciplinary Theoretical and Mathematical Sciences Program (iTHEMS) (C01, Main Research Building, #359) Introduction to iTHEMS: Tetsuo Hatsuda (iTHEMS Director) Lecture and Q&A: Nagisa Hiroshima (iTHEMS) 16:45-18:00 RIKEN Center for Brain Science (CBS) (C56, Ikenohata Research Building, #316) Laboratory for Sensorimotor Integration (Fumi Kubo, Team Leader) 18:30-21:00 Networking Session (C01, Research Building 3F) 9:15-10:30 RIKEN Center for Advanced Photonics (RAP) (C32, Laser Research Building, Mid Conference Room A) Photonics Control Technology Team (Satoshi Wada, Team Leader) 10:45-12:00 RIKEN Center for Sustainable Resource Science (CSRS) (S01, Biological Science Research Building, S311) Molecular Bioregulation Research Team (Shinya Hagihara, Team Leader)

Venue: RIKEN Wako Campus

Asymptotics in astrophysics iTHEMS workshop

February 25 (Tue) - 28 (Fri), 2025

This workshop will include overview talks of application of asymptotics and perturbation theory techniques in (wave transport or oscillation related) astrophysics and cosmology eigenvalue problems. In addition, there will be introductory talks about fundamental asymptotics and perturbation theory techniques used in theoretical physics. The purpose of this interdisciplinary workshop is to identify problems in astrophysics and related fields including, but not limited to, stellar structure and evolution, black holes and high-energy physics which can be solved using existing asymptotics and perturbation theory methods in theoretical physics problems (e.g. quantum field theory, gravity), and vice versa.

Venue: 8F, Integrated Innovation Building (IIB)

Event Official Language: English

Theories of Astrophysical Big Bangs 2025

February 17 (Mon) - 19 (Wed), 2025

We are pleased to announce an international workshop on theories of Astrophysical Big Bangs. The main topics of the workshop are listed below, although the topics are not limited to these areas. We aim to cover a broad range of astrophysical research concerning various types of cosmic explosions and compact objects. Neutron Stars Neutron Star Mergers Gravitational Waves Gamma-Ray Bursts Supernovae Supernova Remnants This workshop aims to assemble leading experts in various fields of astrophysical big bangs for vibrant discussions and to foster new collaborations among participants. Program (last updated 2025.02.17) 17Feb. 10:00-10:10 Opening Remarks by Hiro Nagataki (RIKEN) Special Talk 10:10-11:10 (50+10) Daniel Kasen (U.C. Berkeley) Radiative Transfer Modeling of Explosive Transients NS mergers, Kilonovae, and Gravitational Waves 11:10-11:50 (30+10) Masaomi Tanaka (Tohoku U.) Decoding light curves and spectra of kilonovae 11:50-12:30 (30+10) Kenta Hotokezaka (U. Tokyo) Kilonova Nebular Emission 12:30-14:00 Lunch Break and Poster Session 14:00-14:40 (30+10) Kipp Cannon (U. Tokyo) Selection Effects in Gravitational-Wave Observations 14:40-15:20 (30+10) Koutarou Kyutoku (Chiba U.) Signature of hadron-quark crossover in binary-neutron-star mergers 15:20-15:50 Poster Presentations & Coffee Break 15:50-16:30 (30+10) Luca Baiotti (Osaka U.) Investigating ultra-high-density equations of state through gravitational waves from binary neutron stars mergers Supernovae & Gamma-Ray Bursts (Chair A. Mizuta) 16:30-17:10 (30+10) Nozomu Tominaga (NAOJ) Transient studies using Subaru/Hyper Suprime-Cam 17:10-17:50 (30+10) Tianshu Wang (UCB) Three-Dimensional Long-Term CCSN Simulations: New Insights and Challenges 18 Feb. Gamma-Ray Bursts 9:00-9:30 (25+5) Akira Mizuta (RIKEN) 3D relativistic GRB jet propagation in collapsars 9:30-10:00 (25+5) Jin Matsumoto (Fukuoka U.) Nonlinear dynamics of relativistic magnetized jet with field reversals 10:00-10:30 (25+5) Hirotaka Ito (RIKEN) Numerical simulations of photospheric emission in GRBs 10:30-11:00 (25+5) Maria Dainotti (NAOJ) GRBs and SNe Ia cosmology to cast the Hubble constant tension 11:00-11:30 Poster Presentations & Coffee Break 11:30-12:10 (30+10) Kunihito Ioka (Kyoto U.) GRB Cocoon + Scattering in FRB Neutron Stars 12:10-12:40 (25+5) Hajime Sotani (Kochi U.) Supernova gravitational waves and asteroseismology 12:40-14:00 Lunch Break & Poster Presentations 14:00-14:30 (25+5) Akira Dohi (RIKEN) Modeling of Clocked X-ray Bursters Progenitor Stars 14:30-15:10 (30+10) Hideyuki Umeda (U. Tokyo) Progenitors of low-mass Fe core collapse supernovae and properties of supernova explosions 15:10-15:40 (25+5) Lucy McNeill (Kyoto U.) Finite temperature treatment of white dwarf merger progenitors 15:40-16:10 Poster Presentations & Coffee Break Core-Collapse Supernovae 16:10-16:50 (30+10) Tomoya Takiwaki (NAOJ) Diversity of explosion mechanisms of core-collapse supernovae 16:50-17:30 (30+10) Hiroki Nagakura (NAOJ) Open issues in numerical modeling of core-collapse supernova 17:30-18:10 (30+10) Yudai Suwa (U. Tokyo) Probing supernova interiors with neutrinos 18:30-21:00 Banquet & Poster Presentations 19 Feb. Supernovae, Supernova Remnants, and Nucleosynthesis 10:00-10:40 (30+10) Ke-Jung Chen (ASIAA) Supernovae of very massive stars 10:40-11:20 (30+10) Masaomi Ono (ASIAA) Evolution of core-collapse supernovae from explosion to supernova remnant 11:20-12:00 (30+10) Hiroya Yamaguchi (JAXA) XRISM view of supernova remnants 12:00-12:40 (30+10) Shiu-Hang Lee (Kyoto U.) Super high-speed three-dimensional hydrodynamic simulations of supernova remnants and their applications in the era of microcalorimetric X-ray spectroscopy 12:40-14:00 Lunch Break 14:00-14:40 (30+10) Gilles Ferrand (U. Manitoba) Typing thermonuclear explosions from observations of young supernova remnants 14:40-15:20 (30+10) Nobuya Nishimura (U. Tokyo) Toward new nuclear astrophysics experiments for explosive nucleosynthesis in core-collapse supernovae 15:20-16:00 (30+10) Ryosuke Hirai (RIKEN) Supernovae in binary systems 16:00-17:00 (60) Coffee Break and Free Discussion

Venue: Conference room in Administrative Headquarters (2nd Floor, Feb. 17 and 18) Okochi Hall (Feb.19), RIKEN Wako Campus

Event Official Language: English

Pebbles in Planet Formation

February 10 (Mon) - 13 (Thu), 2025

Research on planet formation involves various approaches, including explorations of small solar system bodies, observations of protoplanetary disks, dust experiments, simulations, and theoretical studies. One of the primary objectives in this field is to develop a comprehensive theory that explains how kilometer-sized planetesimals form from micrometer-sized dust grains, drawing upon findings from these diverse research methods. This workshop will focus on the concept of pebbles, which play a crucial role in the planet formation process. Pebbles — typically defined as solids ranging from millimeter to centimeter in size — are intermediate building blocks in planet formation, though their definition varies depending on the context. Assuming pebbles has led to theoretical advances in mechanisms such as streaming instability and pebble accretion, which promote the formation and growth of planetesimals. Additionally, pebbles have been linked to barriers against dust growth, such as the bouncing barrier. Furthermore, observations of protoplanetary disks have revealed the size distribution and porosity of solids, while the strength and thermal conductivity of comets obtained by the Rosetta mission suggest the accumulation of pebbles due to disk instabilities. However, inconsistencies have been pointed out between pebble formation and theories of dust growth. This workshop aims to revisit and refine our understanding of solid materials implicated in planet formation, particularly in light of findings from solar system explorations and protoplanetary disk observations. We aim to reevaluate the definition and role of pebbles in the broader context of planet formation, with a special focus on the current challenges and open questions in the field. The workshop will include discussions of experiments and simulations of dust growth and collisions, and planetesimal formation mechanisms such as streaming instability. The workshop features keynote talks from the perspectives of explorations, observations, experiments, simulations, and theories, and we also call for presentations on related topics.

Venue: National Astronomical Observatory of Japan (Mitaka Campus) (Main Venue) / via Zoom

Event Official Language: English

High Energy Physics in the Quantum Era

December 2 (Mon) - 4 (Wed), 2024

This workshop is co-hosted by KEK Theory Center and RIKEN iTHEMS to inaugurate their new partnership in theoretical studies of high energy physics and related subjects with special emphasis on development and application of quantum technologies. The workshop aims for developing new connection between particle physics and quantum information/technologies. In the situation where significant progress is expected in the field of quantum information and technologies, it is quite important to discuss how such progress can be used in physics researches. Also, new techniques or new theoretical formulations of quantum field theory/quantum gravity may give deeper understanding of our quantum world. In this workshop, we would like to have world-leading researchers both from particle physics and quantum technologies, and drive lively discussions on future prospects. We are trying to limit the number of talks to be as minimal as possible, so that we have plenty of time for discussions. The workshop is in-person only.

Venue: Kobayashi Hall, KEK Tsukuba Campus

Event Official Language: English

Entanglements & Applications

November 18 (Mon) at 9:30 - 15:00, 2024

Myfanwy Evans (Professor, Institute of Mathematics, University of Potsdam, Germany)
Stephen Hyde (Emeritus Professor, Materials Physics, Australian National University, Australia)
Toky Andriamanalina (Ph.D. Student, Institute of Mathematics, University of Potsdam, Germany)

9:30-10:30: Toky Andriamanalina Title: Untangling 3-periodic entanglements of filaments and nets Abstract: Entanglements of curves and nets can used to describe various biological and chemical structures, such as coordination polymers, liquid crystals, or DNA origami crystals. We recently developed new diagrammatic descriptions of 3-periodic entanglements. These new diagrams are drawn out of a projection along one axis of a unit cell of a 3-periodic structure. By using these diagrams, we define the notion of untangling number for 3-periodic structures, which is a measure of complexity of the entanglement. Thanks to this, it is now possible to characterise the least tangled structures that we call ground states, and in particular we show that the rod packings are the generic ground states of entanglements of curves. 10:30-11:00: coffee break 11:00 - 12:00: Stephen Hyde Title: Tangles... and untangles Abstract: Knots, braids, links, self-entangled nets, multiple catenated infinite nets... are examples of what we call, simply, “tangles”. They are relevant to molecular-scale (bio)materials, from duplexed ssRNA to metal-organic frameworks. We are interested in understanding: 1.Which tangles are “simple”? 2.How tangled is a tangle!? Our tangle toolkit is a simple one: we assemble helices into networks, allowing a broad spectrum of tangles to be built, from knots to tangled nets. Interesting “simple” tangles are entanglements of the edges of Platonic polyhedra [1] and entangled 2-periodic nets [2]. A proposed answer to point 2. above will be discussed. if there is time. The ideas are at present largely unpublished, and being working into a book to be published, we hope, in late 2025 [3]. 13:00 - 14:00: Myfanwy Evans Title: Can solvents tie knots? Helical folds of biopolymers in liquid environments. Abstract: Using a simulation technique based on the morphometric approach to solvation, we performed computer experiments which fold a short open flexible tube, modelling a biopolymer in aqueous environments, according to the interaction of the tube with the solvent alone. We find an array of helical geometries that self-assemble depending on the solvent conditions, including symmetric double helices where the strand folds back on itself and overhand knot motifs. Interestingly these shapes—in all their variety—are energetically favoured over the optimal helix. By differentiating the role of solvation in self–assembly our study helps illuminate the energetic background scenery in which all soluble biomolecules live. This event is organized with the Interdisciplinary Math Study Group.

Venue: Seminar Room #359

Event Official Language: English

iTHEMS Science Outreach Workshop 2024

November 15 (Fri) - 17 (Sun), 2024

This year's meeting on "Outreach of RIKEN iTHEMS 2024@Sendai&Zoom" will be held from FRI November 15 to SUN November 17, as a face-to-face meeting at TOKYO ELECTRON House of Creativity of Tohoku Forum for Creativity in cooperation with iTHEMS SUURI-COOL (Sendai) using ZOOM for the necessary part as well.

Venue: TOKYO ELECTRON House of Creativity, Katahira Campus, Tohoku University (Main Venue) / via Zoom

Event Official Language: Japanese

Knitting Day

November 1 (Fri) at 10:00 - 16:00, 2024

Tomohiko Sano (Senior Assistant Professor, Department of Mechanical Engineering, Faculty of Science and Technology, Keio University)
Samuel Poincloux (Assistant Professor, Department of Physics and Mathematics, College of Science and Engineering, Aoyama Gakuin University)
Taiki Goto (Master's Student, Keio University)
Daisuke Shimamoto (Master's Student, The University of Tokyo)
Kotone Tajiri (Master's Student, Keio University)
Sonia Mahmoudi (Assistant Professor, Mathematical Science Group, Advanced Institute for Materials Research (AIMR), Tohoku University)

The 'Knitting Day' event is a one-day gathering that brings together students and researchers from diverse fields to explore the fascinating connections between the topology and mechanics of knitting. It aims to foster interdisciplinary discussions on how knitting techniques can be understood through mathematical, physical, and engineering lenses and their potential applications in industry. This event is organized with the Interdisciplinary Math Study Group. Schedule: 10:00 – 10:30: Welcome coffee 10:30 – 11:00: Samuel Poincloux 11:10 – 11:30: Kotone Tajiri 11:30 – 12:00: Discussion 12:00 – 13:00: Lunch 13:00 – 13:30: Daisuke Shimamoto 13:40 – 14:00: Taiki Goto 14:00 – 14:30: Discussion 14:30 – 15:10: Sonia Mahmoudi 15:10 – 16:00: Discussion & Coffee Break 16:00-18:00: Internal Discussion From 18:00: Dinner Titles: Taiki Goto: Twist deformation in trefoil knot Sonia Mahmoudi: A new topological model of knitting Samuel Poincloux: Knit mechanics and frictional troubles Daisuke Shimamoto: TBA Kotone Tajiri: Curling morphology of knitted fabrics: structure and mechanics

Venue: #345-347, 3F, Main Research Building

Event Official Language: English

RIKEN Quantum Workshop on “Quantum-Like Modeling” in Cognitive & Social Sciences

October 11 (Fri) at 14:00 - 19:00, 2024

Recently, there has been a growing trend to consider cognitive, and social phenomena as Open Quantum Systems, and to mathematically define the fundamental principles behind them through so-called “Quantum-Like Modeling”. It has been extremely difficult to systematically explain complexities of such phenomena within humans’ cognitive traits based on classical “rational” reasoning. Quantum-Like Modeling suggests that using quantum probability calculus and its applications could be useful to rationalize such phenomena and expand previous understandings, obtained through simple linear algebra, by applying quantum formalizations. Just as physicists explored a new branch of mathematics, the theory of operators in complex Hilbert space, to describe the quantum phenomena in an effective way, considerations here will be built on the methodology and mathematical apparatus of quantum theory and directed to applications outside of physics, namely to, cognition, psychology, decision-making, economics, finances, as well as the social and political sciences. Programme 14:00~14:10 Atsushi Iriki: Introduction. Potential of quantum computing for humanities 14:10~15:10 Andrei Khrennikov: Tutorial. Ubiquitous Quantum: from genetics and biological evolution to cognition, psychology, decision making, and social science 15:10~15:40 Masanao Ozawa: Quantum Instrument -- Measurement to cognition with QC-simulation Break 16:00~16:30 Haruki Emori: Applications of quantum computers to cognitive sciences based on Quantum Instrument 16:30~17:00 Miho Fuyama: Subjective Experiences and Superposition State in Narrative Reading 17:00~17:30 General Discussion 18:00~19:00 Networking Mixer (RIKEN canteen #1) Registration Deadline September 26 (Thur), 2024 (for those attending both the workshop and networking mixer (banquet, free of charge)) October 4 (Fri), 2024 (for those attending only the workshop)

Venue: Seminar Room #359

Event Official Language: English

iTHEMS Cosmology Forum #2 - Stochastic gravitational waves: fossils from the early universe

September 27 (Fri) at 9:00 - 18:00, 2024

Keitaro Takahashi (Professor, Faculty of Advanced Science and Technology, Kumamoto University)
Kazuyuki Sugimura (Assistant Professor, Graduate School of Science, Hokkaido University)
Ryusuke Jinno (Associate Professor, Graduate School of Science, Kobe University)
Yuichiro Tada (Designated Assistant Professor, C-Lab, Department of Physics, Institute for Advanced Research, Nagoya University)

iTHEMS Cosmology Forum Workshop is a series of short workshops, each focused on an emerging topics in cosmology. The targeted audience is cosmologists, high-energy physicists and astronomers interested in learning about the subject, not just those who have already worked on the topic. The goal of the workshop is to provide working knowledge of the topic and leave dedicated time for discussions to encourage mutual interactions among participants. The second workshop is devoted to explanations of the stochastic gravitational wave background (SGWB). The SGWB is a significant detection of GW from pulsar timing arrays. The origin of this background could be either supermassive black holes or primordial. Surprisingly, both of these early Universe mechanisms are not well understood. This one-day workshop gathers both the observational and theoretical aspects of this growing topic. The workshop will be in English. The workshop venue will be either at Main Research Building #435-437 or at Okochi Hall, and we will decide and announce which one will be actually used after the registration is closed. The workshops are organised by the iTHEMS Cosmology Forum working group, which is the successor of the Dark Matter Working Group at RIKEN iTHEMS. Invited Speakers: Keitaro Takahashi (Kumamoto University) TBA Kazuyuki Sugimura (Hokkaido University) Supermassive black hole formation Ryusuke Jinno (Kobe University) First-order phase transitions and gravitational wave production in the early Univers Yuichiro Tada (Nagoya University) Scalar-induced gravitational waves as a cosmological phonograph Time table: 09:00-09:30 -- Opening remarks and coffee 09:30-10:45 -- Takahashi (keynote) 10:45-11:45 -- Sugimura 11:45-13:30 -- Lunch time 13:30-14:30 -- Jinno 14:30-15:30 -- Discussion and coffee 15:30-16:30 -- Tada 16:30-17:30 -- Panel Discussion Organisers: Kohei Hayashi, Nagisa Hiroshima, Derek Inman, Amaury Micheli, Ryo Namba

Venue: #435-437, 4F, Main Research Building

Event Official Language: English

RIKEN - LBNL Workshop on Quantum Information Science

September 3 (Tue) - 6 (Fri), 2024

This international workshop will bring together researchers worldwide to discuss and collaborate on the latest developments in quantum technologies and quantum computing. Other focus areas will be algorithms, hybrid classical - quantum computing, error mitigation, and applications in physics and chemistry. With an emphasis to galvanize the participants into future collaborations, in addition to presentations on recent trends, the workshop will dedicate time in the afternoons for facilitated brainstorming and planning sessions.

Venue: Lawrence Berkeley National Laboratory (Berkeley, California)

Event Official Language: English

NCTS-iTHEMS Joint Workshop on Matters to Spacetime: Symmetries and Geometry

August 26 (Mon) - 29 (Thu), 2024

The National Center for Theoretical Sciences (NCTS) and the Interdisciplinary Theoretical and Mathematical Sciences Program (iTHEMS) at RIKEN have long maintained a collaborative relationship, even before the Memorandum of Understanding was signed in December, 2022. This partnership has successfully facilitated joint activities in high energy physics over recent years. As the impact of the COVID-19 pandemic wanes, we are excited to announce the inaugural joint workshops focusing on condensed matter physics and (quantum) gravity. These workshops are designed to foster international collaborations and stimulate interdisciplinary research. We are pleased to invite you to the 2024 NCTS-iTHEMS Workshop on Matters to Spacetime: Symmetries and Geometry, to be held from August 26 (Monday) to August 29 (Thursday), at the National Center for Theoretical Sciences, located on the campus of National Taiwan University (NTU) in Taipei, Taiwan. This workshop will feature presentations on the latest research findings, foster discussions to spark new ideas, and provide opportunities for initiating collaborative projects. While we strongly encourage in-person attendance to maximize engagement and interaction, an online platform will also be available to accommodate participants who are unable to attend physically.

Venue: NCTS Physics Lecture Hall, 4th Floor, Cosmology Hall, National Taiwan University

Event Official Language: English

Advances in Fluctuating Hydrodynamics: Bridging the Micro and Macro Scales

June 17 (Mon) - 28 (Fri), 2024

Abhishek Dhar (Professor, International Centre for Theoretical Sciences, India)
Luca Delacrétaz (Assistant Professor, The University of Chicago, USA)
Tomohiro Tanogami (Assistant Professor, Department of Earth and Space Science, Graduate School of Science, Osaka University)
Taiki Haga (Assistant Professor, Division of Physics and Electronics, Graduate School of Engineering, Osaka Metropolitan University)
Yukinao Akamatsu (Assistant Professor, Department of Physics, Graduate School of Science, Osaka University)
Keisuke Fujii (JSPS Research Fellow PD, Department of Physics, Graduate School of Science, The University of Tokyo)
Harukuni Ikeda (Assistant Professor, Department of Physics, Faculty of Science, Gakushuin University)
Yuki Minami (Assistant Professor, Graduate School of Engineering, Gifu University)
Hiroyoshi Nakano (Assistant Professor, The Institute for Solid State Physics (ISSP), The University of Tokyo)
Yusuke Nishida (Professor, Department of Physics, Tokyo Institute of Technology)
Makiko Sasada (Professor, Graduate School of Mathematical Sciences, The University of Tokyo)

Establishing universal laws in far-from-equilibrium physical systems is one of the outstanding unresolved problems in modern physics. While we have not reached a complete theory applicable to any nonequilibrium system, hydrodynamics provides a promising theoretical tool, which captures universal macroscopic behaviors of nonequilibrium many-body systems. In particular, a hydrodynamic approach with thermal fluctuation, dubbed fluctuating hydrodynamics, successfully describes normal hydrodynamic transports in three-dimensional systems as well as anomalous transports (related to the Kardar–Parisi–Zhang universality class) in low-dimensional systems. The purpose of this workshop is to bring together theorists working on both classical and quantum many-body problems and to explore nonequilibrium physics from the viewpoint of fluctuating hydrodynamics.

Venue: Panasonic Hall, Yukawa Institute for Theoretical Physics, Kyoto University (Main Venue) / via Zoom

Event Official Language: English