ニュース
85件のニュース / 2023年

20230530
受賞情報小澤 知己客員研究員がAsian Young Scientist Fellowshipを獲得
小澤 知己（iTHEMS 客員研究員 / 東北大学 材料科学高等研究所 (AIMR) 准教授）が、2023年度のAsian Young Scientist Fellowshipに選出されました。 このフェローシップは、生命科学、物理科学、数学・コンピューターサイエンスの3つの分野いずれかで活躍するアジアの若手科学者を支援することを目的として設立されたものです。 小澤氏は、フォトニクスにおける人工次元を用いたトポロジカル状態への貢献が認められ、AMOプラットフォームにおける多体物理のさらなる探求が期待されての選出となりました。 詳細は、関連リンクをご覧下さい。

20230528
セミナーレポートExploring GPT’s Influence on Natural Science and Mathematics on May 17, 2023
The emergence of ChatGPT has shocked the world. Its influence on our society is inestimable, both for its possibility and its potential risk. Together with MLPhys (Foundation of “Machine Learning Physics”), we held a workshop “Exploring GPT’s Influence on Natural Science and Mathematics” on 17th May, to discuss the influence of GPT particularly on natural science and mathematics. An introductory lecture on GPT (generative pretrained transformer) and LLM (large language model) was given by Mr. Shota Imai (The University of Tokyo), and an introductory lecture on proof assistant system (automated theorem proving) was given by Dr. Yoshihiro Mizoguchi (Kyushu University). Around 30 people attended in place, and over 400 people attended the workshop online. Lively discussion took place among specialists of Mathematics, Physics and Computer science. Reported by Taketo Sano (iTHEMS, RIKEN)

20230526
セミナーレポートMathPhys Seminar by Dr. Masazumi Honda on February 16, 2023
On Febururary 16, Masazumi Honda gave a talk. He explained his recent results on the relationship between Riemann hypothesis and fourdimensional N=4 supersymmetric YangMills theory. Reported by Keita Mikami

20230525
今週の論文Week 4, May 2023
Title: A Stochastic Approach To Reconstruct Gamma Ray Burst Lightcurves Author: Maria G. Dainotti, Ritwik Sharma, Aditya Narendra, Delina Levine, Enrico Rinaldi, Agnieszka Pollo, Gopal Bhatta arXiv: http://arxiv.org/abs/2305.12126v2 Title: Chiral anomaly in a (1+1)dimensional Floquet system under highfrequency electric fields Author: Kenji Fukushima, Yoshimasa Hidaka, Takuya Shimazaki, Hidetoshi Taya arXiv: http://arxiv.org/abs/2305.11432v1

20230525
セミナーレポートiTHEMS Math Seminar by Dr. Kohei Hayashi on May 24, 2023
On May 24, there was a math seminar by Kohei Hayashi. In the first part of his talk, he start by explaining the idea of the hydrodynamic limit and the fluctuating hydro dynamic limit. He then explained Markov chain and how to obtain the diffusion equation. In the second part, he explained KPZ equation and its universality. Reported by Keita Mikami

20230522
ホットトピックRyosuke Iritani gave a scientific outreach talk at Mathcafe on May 14, 2023
On Sunday 14th May, Ryosuke Iritani gave a scientific outreach talk at Mathcafe. He focused on spatial biodiversity as a chief topic and how to use mathematics to estimate, and make inferences for, the biodiversity. He explained the measurement of biodiversity from the axiomatic viewpoint, that is, he explained what properties should be satisfied by the quantity that is supposed to measure biodiversity. He then moved on to explaining an application of generating functions to biodiversity measures. He finished his talk by saying that mathematics is not only useful to science but also a lifetime fun hobby.

20230522
セミナーレポートABBLiTHEMS Joint Astro Seminar by Mr. Vincenzo Sapienza on May 19, 2023
Synchrotron Xray emission in young supernova remnants (SNRs) is a powerful diagnostic tool to study the population of high energy electrons accelerated at the shock front. Mr. Sapienza and his collaborators performed a spatially resolved spectral analysis of the young Kepler's SNR, where they identify two different regimes of particle acceleration. In the north, where the shock interacts with a dense circumstellar medium (CSM), they found a more efficient acceleration than in the south, where the shock velocity is higher and there are no signs of shock interaction with dense CSM. They also studied the temporal evolution of the synchrotron flux, from 2006 to 2014. A number of regions show a steady synchrotron flux and equal cooling and acceleration times. However, they found some regions where they measured a significant decrease in flux from 2006 to 2014. Our results display a coherent picture of the different regimes of electron acceleration observed in Kepler's SNR. Also Mr. Sapienza presented some preliminary results on the SN 1987A project. Reported by Shigehiro Nagataki

20230518
今週の論文Week 3, May 2023
Title: Embedding and correlation tensor for XRP transaction networks Author: Abhijit Chakraborty, Tetsuo Hatsuda, Yuichi Ikeda arXiv: http://arxiv.org/abs/2305.09917v1 Title: Exploring $^3P_0$ Superfluid in Dilute SpinPolarized Neutron Matter Author: Hiroyuki Tajima, Hiroshi Funaki, Yuta Sekino, Nobutoshi Yasutake, Mamoru Matsuo arXiv: http://arxiv.org/abs/2305.08690v1 Title: Tensor category equivariant KKtheory Author: Yuki Arano, Kan Kitamura, Yosuke Kubota arXiv: http://arxiv.org/abs/2305.07255v1 Title: Firstorder phase transitions in YangMills theories and the density of state method Author: Biagio Lucini, David Mason, Maurizio Piai, Enrico Rinaldi, Davide Vadacchino arXiv: http://arxiv.org/abs/2305.07463v1

20230517
ホットトピックThomas Hitchcock gave a short talk at Nerd Nite Tokyo on April 21, 2023
On Friday 21st April, Thomas Hitchcock gave a short talk at Nerd Nite Tokyo entitled “Sex Education: reproductive diversity across the tree of life”. There he talked to a general audience about the range of ways that organisms may reproduce, from those organisms that simply make copies of their own genes (asexual reproduction), to those that mix them with others (sexual reproduction), and those that can do both (facultative sex). He discussed the different mechanisms that organisms may use to decide whether to reproduce as a female (producing eggs) or male (producing sperm), and how genes may pass differently to offspring through these two routes, illustrating these ideas with stories about spoonworms, fungus gnats, and rotifers. Finally, he stressed how evolution may work differently in these different reproductive systems, and so the importance of understanding this diversity for guiding our efforts in conservation, agriculture, and medicine.

20230515
セミナーレポートSpring Workshop on Quantum Gravity on April 26, 2023
Spring Workshop on Quantum Gravity, the first one in the lecture series Quantum Gravity Gatherings and cosponsored by NCTS, was a great success with about 50 participants, including some from Taiwan. First, Prof. Kawai's intensive lecture on quantum gravity was wonderful. In the basic part of the first half, he explained the physical aspects of the ordinary formulas found in textbooks on general relativity, from a quantum theoretical standpoint, and transformed the equations consistently, to arrive at physically clear results about quantum gravitational fields. In the latter part, he described the features of fieldtheoretic quantum gravity and its limitations. Through these, he showed us the importance of researching quantum gravity step by step from a fundamental point of view. All participants were interested in quantum gravity, and there was an atmosphere of togetherness in the room. During the lecture, a variety of questions, from the simple to the fundamental, were raised. During breaks, small discussions spontaneously occurred here and there in the common space. And in the short talk sessions, we were able to share each other's research and interests. The banquet on the first day of the event was a great opportunity to deepen friendship. Thus, this event provided many opportunities for learning, research, and exchange for the younger generation. Reported by Yuki Yokokura

20230512
セミナーレポートDMWG Seminar: DMline search in the Galactic Center with MAGIC telescope
Among kinds of dark matter (DM) candidates, weakly interacting massive particles (WIMPs) are the most intensively studied ones along their theoretical background and expectations for the signals in onEarth experiments. However, up to now, our understanding of the regime of m>O(1) TeV is still limited since we cannot produce them at colliders and cannot expect a sufficient interaction rate at underground recoil detectors. Highenergy astrophysical observations are powerful in probing that regime and projects all over the world are now searching for corresponding signals. When we look for signatures of DM from astrophysical data, it is necessary to consider contributions from astrophysics very carefully. The key signatures could be the morphology of the emission, the spectrum, and correlating signals in other kinds of observations, variabilities, and so on. If DM particles annihilate to produce photon pairs, the spectrum should show a monochromatic peak corresponding to the mass of DM, hence it is distinctive against the astrophysical emissions. MAGIC telescope, which locates in the Northern Hemisphere, only considers target objects in the northern sky previously. However, it actually can see the Galactic Center in a large inclination. For this case, the threshold of the analysis is worsened but the effective area is improved, then it can achieve a good sensitivity to highenergy emissions. Using 223h of observation at the Galactic Center with MAGIC, the line emission search is carefully performed. The determination of the "off" takes an important role in not overestimating the sensitivity and the sliding window technique is adopted regarding this point. The uncertainty of the DM density of the region of interest is also carefully discussed by performing the analysis applying both the cuspy and cored profiles. No signatures of the monochromatic gammaray from DM annihilation are found in this analysis hence we obtain upper limits of the annihilation crosssection. The sensitivity is comparable to the flux level of a wellmotivated Wino DM model which should exhibit annihilation lines around E~3TeV. This means that we are now approaching the era that to probe detailed particle models of DM with astrophysical observations. In the near future, observations with the Cherenkov Telescope Array will start operations and we can look into the detail of the models in combination with particle physics communities! Reported by Nagisa Hiroshima

20230511
今週の論文Week 2, May 2023
Title: Ceratozamia rosea (Zamiaceae): A new species from the Northern Mountains of Chiapas, Mexico Author: José GarcíaGonzález, Miguel Angel PérezFarrera, José Said GutiérrezOrtega, Andrew P. Vovides, Pedro DíazJiménez Journal Reference: Phytotaxa 595(1): 7388 (2023) doi: https://doi.org/10.11646/phytotaxa.595.1.5 Title: Zamia magnifica (Zamiaceae, Cycadales): A New Rupicolous Cycad Species from Sierra Norte, Oaxaca, Mexico Author: Miguel Angel PérezFarrera, José Said GutiérrezOrtega, Mauricio Gerónimo MartínezMartínez, Michael Calonje Journal Reference: Taxonomy 3(2): 232249 (2023) doi: https://doi.org/10.3390/taxonomy3020017 Title: Nonexpansive and noncontractive mappings on the set of quantum pure states Author: Michiya Mori, Peter Šemrl arXiv: http://arxiv.org/abs/2305.05123v1 Title: HigherForm Symmetry and Eigenstate Thermalization Hypothesis Author: Osamu Fukushima, Ryusuke Hamazaki arXiv: http://arxiv.org/abs/2305.04984v1 Title: Quantum Velocity Limits for Multiple Observables: Conservation Laws, Correlations, and Macroscopic Systems Author: Ryusuke Hamazaki arXiv: http://arxiv.org/abs/2305.03190v1 Title: Hidden Conformal Symmetry from the Lattice Author: LSD Collaboration, T. Appelquist, R. C. Brower, K. K. Cushman, G. T. Fleming, A. Gasbarro, A. Hasenfratz, J. Ingoldby, X. Y. Jin, E. T. Neil, J. C. Osborn, C. Rebbi, E. Rinaldi, D. Schaich, P. Vranas, E. Weinberg, O. Witzel arXiv: http://arxiv.org/abs/2305.03665v1 Title: The impact of effective matter mixing based on threedimensional hydrodynamical models on the molecule formation in the ejecta of SN 1987A Author: Masaomi Ono, Takaya Nozawa, Shigehiro Nagataki, Alexandra Kozyreva, Salvatore Orlando, Marco Miceli, KeJung Chen arXiv: http://arxiv.org/abs/2305.02550v1

20230511
今週の注目人物Selfintroduction: 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 KardarParisiZhang 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.

20230508
ホットトピックブラックホールの響きで探る極限重力の物理
Naritaka Oshita (Visiting Scientist, iTHEMS) contributed to the chapter “Researches” in the membership journal of the physical society of Japan on the universality in a black hole ringing and its application to probe the nearhorizon physics of black holes. Also, a picture relevant to Naritaka Oshita’s research on a black hole ringing was selected as the cover art of the journal. You can visit the following web site of the Physical Society of Japan to access the contributions.

20230508
書籍原生生物学事典
矢崎 裕規／新倉 保／猪飼 桂／矢吹 彬憲／永宗 喜三郎／松崎 素道／白鳥 峻志／島野 智之／小林 富美惠 [編] 発売日：2023年05月10日 原生生物を対象とした様々な研究とそこから明らかとなってきた新たな知見を紹介し、進化、生態、人との関係など、幅広い知識と最新の情報を包括する事典。近年の分類体系についても整理。〔内容〕原生生物とは（細胞構造、系統と分類、大進化、共生、生態学、モデル生物）／進化と分類（アメーボゾア、アーケプラスチダ、ストラメノパイル、アルベオラータ他）／原生生物の構造・生態（生活環、構造と機能、共生系、ゲノミクス、環境と生態、人との関わり他）／研究手法。

20230504
今週の論文Week 1, May 2023
Title: Nonlinear chiral kinetic theory Author: Kazuya Mameda arXiv: http://arxiv.org/abs/2305.02134v1 Title: Spatial deformation of manybody quantum chaotic systems and quantum information scrambling Author: Kanato Goto, Taozhi Guo, Tomoki Nosaka, Masahiro Nozaki, Shinsei Ryu, Kotaro Tamaoka arXiv: http://arxiv.org/abs/2305.01019v1

20230502
ホットトピックRIKEN iTHEMS signed a new MoU with Lawrence Berkeley National Laboratory (LBNL)
Reiner Kruecken (Director of the Nuclear Science Division of LBNL) and Tetsuo Hatsuda (Director of RIKEN iTHEMS) are the principal coordinators for LBNL and RIKEN iTHEMS, respectively, for this MoU [1]. The photo was taken in front of the desk of Ernest Lawrence [2], which is preserved at LBNL.

20230428
今週の注目人物Selfintroduction: Rongyang Sun
My name is Rongyang Sun. I joined RIKEN in October 2021 as a Postdoctoral Researcher in RCCS and RQC. Now, I am very glad to hold this concurrent position in iTHEMS. As a fullstack researcher in computational quantum manybody physics, my ultimate goal is to understand the fantabulous nature of quantum manybody systems by taking advantage of modern supercomputing systems and quantum computers. Towards this goal, I am developing advanced tensor network algorithms, maintaining highperformance 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 nearterm quantum computers to arrive at the same destination.

20230428
今週の注目人物Selfintroduction: Tomonori Shirakawa
My name is Tomonori Shirakawa. I joined iTHEMS as a Senior Research Scientist in April 2023. I am interested in quantum manybody phenomena in condensed matter physics. To better understand quantum manybody phenomena, I have been working with various numerical methods. In particular, I have recently been exploring more efficient ways to solve quantum manybody problems using quantumclassical hybrid algorithms, quantum algorithms, and tensor network methods.

20230427
セミナーレポートiTHEMS Biology Seminar by Mr. Naoki Konno on April 20, 2023
In April 20, Mr Naoki Konno (University of Tokyo) gave a fantastic talk about the machine leaning method for the prediction of evolution. The talk was entitled, “Machine learning predicts biological system evolution by gene gains and losses”. To my knowledge, this study using genome data of ~3000 species is one of few seminal attempts to theoretically predict longterm and systemlevel evolution. The seminar by Konno san was very clear and we understood the predictability of the proposed framework, called “Evodictor”. In the beginning of the talk, he kindly explained the theoretical basis about phylogenetic tree estimation and machine learning for nonspecialists for which we could enjoy and learn from his seminar a lot. Thank you, Konnosan for the great talk!! Reported by Gen Kurosawa

20230424
リサーチニュースRIKEN Research: Quantum ‘magic’ could help explain the origin of spacetime
A quantum property dubbed ‘magic’ could be the key to explaining how space and time emerged, a new mathematical analysis by three RIKEN physicists suggests [1]. It’s hard to conceive of anything more basic than the fabric of spacetime that underpins the Universe, but theoretical physicists have been questioning this assumption. “Physicists have long been fascinated about the possibility that space and time are not fundamental, but rather are derived from something deeper,” says Kanato Goto of the RIKEN Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS). To read more, please visit the related link.

20230424
セミナーレポートABBLiTHEMS Joint Astro Seminar by Dr. Kumiko Kotera on April 18, 2023
We are living exciting times: we are now able to probe the most violent events of the Universe with diverse messengers (cosmic rays, neutrinos, photons and gravitational waves). One challenge to complete the multimessenger picture resides in the highest energies, as no ultrahigh energy neutrinos have been observed yet. This challenge could be undertaken by the GRAND (Giant Radio Array for Neutrino Detection) project, which aims at detecting ultrahigh energy particles, with a colossal array of 200'000 antennas over 200'000 km2, split into ~20 subarrays of ~10'000 km2 deployed worldwide. In this talk, Kumiko Kotera presented preliminary designs and simulation results, plans for the ongoing, staged approach to construction, and the rich research program made possible by the proposed sensitivity and angular resolution. Reported by Shigehiro Nagataki

20230420
今週の論文Week 4, April 2023
Title: Investigating Time Evolution of Thermal Emission from the Putative Neutron Star in SN 1987A for 50+ Years Author: Akira Dohi, Emanuele Greco, Shigehiro Nagataki, Masaomi Ono, Marco Miceli, Salvatore Orlando, Barbara Olmi arXiv: http://arxiv.org/abs/2304.08418v1 Title: The Impacts of NeutronStar Structure and Base Heating on Type I XRay Bursts and Code Comparison Author: Guoqing Zhen, Guoliang Lv, Helei Liu, Akira Dohi, Bobuya Nishimura, Chunhua Zhu, Liyu Song, Weiyang Wang, Renxin Xu arXiv: http://arxiv.org/abs/2304.07197v1 Title: Plausible presence of new state in neutron stars with masses above $0.98M_{\rm TOV}$ Author: MingZhe Han, YongJia Huang, ShaoPeng Tang, YiZhong Fan doi: https://doi.org/10.1016/j.scib.2023.04.007 arXiv: http://arxiv.org/abs/2207.13613v2

20230417
リサーチニュースRIKEN Research: Gravitational waves could indicate transition to strange quark matter
Telltale signatures in gravitationalwave signals from merging neutron stars should reveal what happens to matter at the extreme pressures generated during such mergers, calculations by RIKEN researchers predict [1]. If you took some water and compressed it with a piston, it would shrink as the molecules get pushed closer together. If you continued ramping up the pressure, you’d reach a point where the atoms collapse and form an ultradense soup of neutrons and protons. The only place in the Universe where this happens is neutron stars, the collapsed remnants of burnedout stars, and it produces mindboggling densities—one teaspoon of such material weighs several hundred billion kilograms. But what would happen if you continued to increase the pressure still further? Not even astrophysicists know the answer to that. To read more, please visit the related link.

20230413
今週の論文Week 3, April 2023
Title: Observing Supernova Neutrino Light Curves with SuperKamiokande. IV. Development of SPECIAL BLEND: a New Public Analysis Code for Supernova Neutrinos Author: Akira Harada, Yudai Suwa, Masayuki Harada, Yusuke Koshio, Masamitsu Mori, Fumi Nakanishi, Ken'ichiro Nakazato, Kohsuke Sumiyoshi, Roger A. Wendell arXiv: http://arxiv.org/abs/2304.05437v1 Title: From diffeomorphisms to exotic phenomena in small 4manifolds Author: Hokuto Konno, Abhishek Mallick, Masaki Taniguchi arXiv: http://arxiv.org/abs/2304.05997v1 Title: GammaRay Emission in the Seyfert Galaxy NGC 4151: Investigating the Role of Jet and Coronal Activities Author: Yoshiyuki Inoue, Dmitry Khangulyan arXiv: http://arxiv.org/abs/2304.04138v1

20230413
セミナーレポートSeminar, "Introduction to the Renormalization group method as a powerful reduction method of dynamics" by Dr. Teiji Kunihiro on April 10, 2023
In April 10, Dr Teiji Kunihiro (Prof Emeritus, Kyoto Univ) gave an introductory talk about the renormalization group method, entitled “Introduction to the Renormalization group method as a powerful reduction method of dynamics.” In fact, this talk was the first seminar at our new seminar room #359 with the splendid blackboard in RIKEN Wako Campus. The talk by Kunihirosan using the blackboard was very very clear, and we can understand the power of the Renormalization group method and its applicability [1]. The talk was also delivered via Zoom (i.e. ~35 participants in total), and there were lively discussions between the lecturer and the audience. After the talk, he kindly shared his lecture note with us so that we can take advantage of it. Thank you, Kunihirosan for the wonderful talk!! Reported by Gen Kurosawa

20230411
セミナーレポートLabTheory Standing Talks #1 by Dr. Hideshi Ooka on March 16, 2023
The first LabTheory standing talk took place on March 16th, 2023, inviting Hideshi Ooka from CSRS (Riken Center for Sustainable Resource Science). He picked up the chemical process of making hydrogen from water as the subject. By design, the event is organized in a very informal setting."I was glad that the speaker prepared very few slides and all the slides were simple because it gave the audience an opportunity to ask many random questions in all sorts of direction," one of the participants, Catherine Beauchemin says. As she says, "in this light and flexible format, it is the audience that can decide what aspects are more interesting for them and ask more questions about it," there have been many questions asked and discussions followed. The event appears to be fruitful for the speaker too; "I will share the comment with my colleagues, as I believe it is a chance to advance the level of chemistry in our lab, " Hideshi Ooka concludes. Reported by Tsukasa Tada

20230410
今週の注目人物Selfintroduction: 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.

20230407
セミナーレポートiTHEMS Biology Seminar by Dr. Yohei Nakayama on March 30, 2023
On March 30th, Dr. Nakayama talked about F1ATPase from both experimental and theoretical aspects. In the introduction, he reviewed biological molecular motors and experimental facts. Then he introduced a Langevin model for the kinetics of F1 and explained how a specific case of the model fits the previous experiments. In the main part, he told us about new experimental results, relation to the theoretical model, and theoretical prediction based on the model. We thank Dr. Nakayama for giving us an exciting presentation. Reported by Kyosuke Adachi

20230407
今週の注目人物Selfintroduction: 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 nongravitational theory in a lowerdimensional system. Recently, I am interested in studying statistical physics with the help of the AdS/CFT correspondence. Thermal states in nongravitational 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.

20230406
今週の論文Week 2, April 2023
Title: AtiyahHirzebruch spectral sequence for topological insulators and superconductors: $E_2$ pages for 1651 magnetic space groups Author: Ken Shiozaki, Seishiro Ono arXiv: http://arxiv.org/abs/2304.01827v1 Title: Frobenius algebras associated with the $α$induction for equivariantly braided tensor categories Author: Mizuki Oikawa arXiv: http://arxiv.org/abs/2303.11845v1 Title: Involutions, links, and Floer cohomologies Author: Hokuto Konno, Jin Miyazawa, Masaki Taniguchi arXiv: http://arxiv.org/abs/2304.01115v1

20230406
今週の注目人物Selfintroduction: CheYu Chen
Hi, my name is CheYu 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 LeCosPANTU (20192020) and then became an AS postdoc at the Institute of Physics, Academia Sinica (20202023), 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 stateoftheart black hole observations to test general relativity (GR), or even to probe putative nonGR 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 nonGR physics, some of which could even be motivated by quantum gravitational effects. These nonGR physics could induce nontrivial 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.

20230405
今週の注目人物Selfintroduction: 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.

20230405
今週の注目人物Selfintroduction: 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 manybody systems and nonequilibrium 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.

20230331
プレスリリース取引ネットワークの相関テンソルによる暗号資産の価格バーストの予測 ―安心して使える暗号資産とデジタル経済の実現にむけて―
暗号資産は、デジタル経済の時代に欠かせない存在となりつつあります。理研と京大の共同研究では、ネットワークの数理科学を駆使することによって、マネーロンダリングや詐欺などの異常事象の検出、価格バーストの予知を行う理論的研究に取り組んでいます。池田裕一（京都大学総合生存学館教授）、アビジット・チャクラボルティ（同特定助教/iTHEMS客員研究員）、初田哲男（理化学研究所数理創造プログラムディレクター）の研究グループは、暗号資産の取引ネットワークに対応する相関テンソルのスペクトルを解析する新規手法を開発して、相関テンソルの最大特異値が暗号資産の価格と有意な負の相関を示すことを発見しました。この発見を用いて、価格バーストの早期指標を提供できる見通しを得ました。 詳細は、関連リンクから京都大学のプレスリリース記事をご覧ください。

20230331
受賞情報Dr. Thomas Hitchcock received the "Best English Presentation Award" of Ecological Society of Japan
Thomas Hitchcock (SPDR, iTHEMS) received the "Best English Presentation Award" at the 70th Annual meeting of the Ecological Society of Japan (ESJ) held on March 2023 for his presentation on "Paternal genome elimination promotes altruism in viscous populations". Congratulations, Thomas!

20230331
受賞情報Dr. José Said GutiérrezOrtega received the "Excellent English Presentation Award" of Ecological Society of Japan
José Said GutiérrezOrtega (SPDR, iTHEMS) received the "Excellent English Presentation Award" at the 70th Annual meeting of the Ecological Society of Japan (ESJ) held on March 2023 for his presentation on "Disparate patterns of niche evolution in the diversification of the Neotropical cycad genus Ceratozamia (Zamiaceae)". Congratulations, José !

20230331
ホットトピックMessages from Tetsuo Hatsuda (March 31, 2023)
Dear iTHEMS members Today is the last day of FY2022. I would like to express my deepest gratitude to all of you for your efforts in overcoming the pandemic this year and continuing your research activities. I would also like to thank the following people who physically have left or are leaving iTHEMS for their great contributions to iTHEMS during FY2022. Bon Voyage! Etsuko Itou, Masaki Taniguchi, Naritaka Oshita, Takuya Sugiura, Yuki Yazaki, Matthias Berwein, Akira Matsumoto, Chris Bourne, Michiya Mori, Shou Yoshikawa, Don Warren, Shunsuke Kobayashi, Hiroshi Yokota, Gilberto Nakamura, Kazumi Kuwata. With best regards, Tetsuo Hatsuda

20230329
受賞情報The paper coauthored by Dr. Ryosuke Iritani has been selected as "Editors' Choice" of OIKOS
The paper entitled "Species interactions and diversity: a unified framework using Hill numbers" coauthored by Dr. Ryosuke Iritani (Research Scientist, iTHEMS) has been selected as the Editors' Choice in OIKOS. Congratulations!

20230329
書籍物性物理とトポロジー  非可換幾何学の視点から
窪田陽介 [著]

20230328
ホットトピックFarewell message from Dr. Euki YAZAKI
Our colleague Euki YAZAKI will move to the Research Center for Advanced Analysis, National Agriculture and Food Research Organization as a Research Scientist from April 1st. We all will miss him and wish him the best of luck in his latest endeavor. Here is a message from Euki YAZAKI: As I prepare to leave after three wonderful years at RIKEN, I would like to take this opportunity to express my gratitude to all of you. It has been an honor to work with such a wonderful group of theoretical and mathematical scientists and I have learned so much from each and every one of you. I would like to thank all my colleagues who have supported me during my time at iTHEMS. Your expertise and enthusiasm have been invaluable, and I am grateful for the time I have spent with you. I would also like to thank the staff at iTHEMS support for their many supports. Although I will be moving on to new adventures, I hope to continue to enjoy good research with iTHEMS members in the future.

20230327
セミナーレポートiTHEMS Biology Seminar by Dr. Midori Tuda on March 23, 2023
Dr. Tuda gave us a very wellprepared, clear and interesting presentation about her group's current research. Her work is primarily experimental, while iTHEMS Biology members' work is primarily theoretical, which could create interesting opportunities. We found many common interest between her research and that of iTHEMS Biology members, such as niche divergence under a changing climate (GutiérrezOrtega), sex ratio of offsprings (Hitchcock), and species coexistence/competition (Iritani). This gave rise to many interesting questions, comments and exchanges. We hope to continue conversation. Reported by Catherine Beauchemin

20230323
今週の論文Week 4, March 2023
Title: Gradientflowed order parameter for spontaneous gauge symmetry breaking Author: Kengo Kikuchi, Kenji Nishiwaki, Kinya Oda arXiv: http://arxiv.org/abs/2303.10841v1 Title: Toric nonarchimedean $μ$entropy and thermodynamical structure Author: Eiji Inoue arXiv: http://arxiv.org/abs/2303.09090v1

20230323
ホットトピックFarewell message from Dr. Akira Matsumoto
Our colleague Akira Matsumoto will move to the Yukawa Institute for Theoretical Physics, Kyoto University as a ProgramSpecific Researcher from April 1st. We all will miss him and wish him the best of luck in his latest endeavor. Here is a message from Akira Matsumoto: I have been a member of iTHEMS for almost one year, which is the first opportunity for me to work as a postdoc. In spite of the difficult situation of COVID19, I was able to enjoy research activity thanks to a good environment of iTHEMS and great effort by assistants. It is interesting to join seminars and discussions freely with researchers from various fields. I would like to thank all the iTHEMS members for giving me nice experiences. I plan to be a visiting scientist of iTHEMS after leaving RIKEN. I am very happy to keep in contact with iTHEMS members and looking forward to collaboration in the future.

20230322
受賞情報Dr. Yalong Cao received FY2022 RIKEN Excellent Achievement Award
Yalong Cao (Research Scientist, iTHEMS) received the FY2022 RIKEN BAIHO Award (梅峰賞) (RIKEN Excellent Achievement Award" for his excellent achievement on "Study of DonaldsonThomas Invariants on CalabiYau 4folds". Congratulations!

20230316
今週の論文Week 3, March 2023
Title: Coupled Hénon Map, Part II: Doubly and Singly Folded Horseshoes in Four Dimensions Author: Jizhou Li, Keisuke Fujioka, Akira Shudo arXiv: http://arxiv.org/abs/2303.06824v1 Title: Coupled Hénon Map, Part I: Topological Horseshoes and Uniform Hyperbolicity Author: Keisuke Fujioka, Ryota Kogawa, Jizhou Li, Akira Shudo arXiv: http://arxiv.org/abs/2303.05769v1

20230316
ホットトピックFarewell message from Dr. Hiroshi Yokota
Our colleague Hiroshi Yokota has moved to the Graduate School of Human and Environmental Studies, Kyoto University as a CREST postdoctoral researcher from March 1, 2023. We all will miss him and wish him the best of luck in his latest endeavor. Here is a message from Hiroshi Yokota: I had worked at iTHEMS as a postdoctoral researcher for almost 4 years. I would like to thank all the iTHEMS members for the valuable discussions on their researches including my own research. Moreover, in iTHEMS, I had very good opportunities to attend the exciting seminars and colloquiums which gave me brilliant ideas from the various fields: physics, biology, mathematics and information. I enjoyed the discussions, the seminars and the colloquiums in iTHEMS. I also would like to thank all assistants who gave us the comfortable research environment. Fortunately, I am allowed to be the visiting scientist in iTHEMS. I hope to discuss with iTHEMS members in future also.

20230315
ホットトピックFarewell message from Dr. Naritaka Oshita
Our colleague Naritaka Oshita will move to the Kyoto University as a Hakubi assistant professor from April 1st. We all will miss him and wish him the best of luck in his latest endeavor. Here is a message from Naritaka Oshita: I enjoyed studying gravity and black holes while being a part of iTHEMS and participating in some iTHEMS events and activities. As of the end of this March, it has been almost two years since I started my second postdoc at iTHEMS as an SPDR fellow in 2021 April. From 2023 April, I will be a Hakubi assistant professor at Kyoto University and will start my exciting new research to understand the mystery of gravity. I enjoyed discussing with many iTHEMS members who are working on physics, biology, mathematics, (quantum) information theory, etc. I thank all faculties, researchers, and students at iTHEMS for having exciting discussions with me! iTHEMS assistants have been contributing to this group to improve the research environment at iTHEMS and they kindly helped me a lot when I needed their help and was in trouble. I appreciate all the assistants at iTHEMS for their support and for having fun conversations! Again, thank you to all members at iTHEMS for everything! I will still be a part of iTHEMS as a visiting researcher. I hope I can have exciting discussions and conversations with you in the future. See you again!

20230315
リサーチニュースRIKEN NEWS: 基礎科学特別研究員インタビュー② 38歳でたどり着いた数学者としての大きな第一歩
佐野 岳人 基礎科学特別研究員のインタビュー記事が、理研の研究紹介ページ「クローズアップ科学道 2023」に掲載されました。 理研には、国際的に活躍する研究者の育成を目指し、若手研究者が自ら設定した研究課題を自由な発想で主体的に研究できる「基礎科学特別研究員制度」があります。1989年に始まったこの制度は、現在公募中の2024年度採用で35回目となります。これを機に、各分野で活躍する先輩たちと現役にインタビューしました。第2回は、数理創造プログラム（iTHEMS）の佐野 岳人 基礎科学特別研究員です。 続きは、関連リンクをご覧ください。

20230313
ホットトピックFarewell message from Dr. Masaki Taniguchi
Our colleague Masaki Taniguchi will move to the Kyoto University as an assistant professor from April 1st. We all will miss him and wish him the best of luck in his latest endeavor. Here is a message from Masaki Taniguchi: I'd like to thank the program director and assistants for many helpful supports over these three years and also many research members for discussing with me. I spent three years in iTHEMS as a mathematical researcher(SPDR). During the three years, I could concentrate on doing my research and communicating with researchers in other fields. In particular, I had been attending a weekly seminar focusing on interactions between math and physics. It was a valuable experience to feel various viewpoints from physics. Also, I got a chance to give a presentation at an event of RIKEN for high school or junior high school students. In my final year, I was chosen as a research member of a program at MSRI and spent four months at Berkeley to communicate with many researchers in my field. I could also invite several researchers to the math seminar and had good opportunities to promote research. I appreciate a good environment in iTHEMS so that I could have these experiences. From this April, I’ll be an assistant professor at Kyoto University. But, I still have several collaborators in iTHEMS, so I’d like to continue discussing with many researchers in iTHEMS as a visiting researcher.
85件のニュース / 2023年