コロキウム
48 イベント
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コロキウムEmergence of Extreme Universe from Quantum Information
2023年4月17日(月) 16:00 - 17:30
高柳 匡 (京都大学 基礎物理学研究所 教授)
Recently, a new interpretation of gravitational spacetime in terms of quantum entanglement has been obtained. The idea of holography in string theory provides a simple geometric computation of entanglement entropy. This generalizes the well-known Bekenstein-Hawking formula of black hole entropy and strongly suggests that a gravitational spacetime consists of many qubits with quantum entanglement. Also a new progress on black hole information problem has been made recently by applying this idea. I will explain these developments in this colloquium.
会場: via Zoom
イベント公式言語: 英語
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コロキウム
Scaling Optimal Transport for High dimensional Learning
2023年1月24日(火) 17:00 - 18:30
Dr. Gabriel Peyré (Research Director, CNRS/École Normale Supérieure, France)
iTHEMS-AIP Joint Colloquium Optimal transport (OT) has recently gained a lot of interest in machine learning. It is a natural tool to compare in a geometrically faithful way probability distributions. It finds applications in both supervised learning (using geometric loss functions) and unsupervised learning (to perform generative model fitting). OT is however plagued by the curse of dimensionality, since it might require a number of samples which grows exponentially with the dimension. In this talk, I will explain how to leverage entropic regularization methods to define computationally efficient loss functions, approximating OT with a better sample complexity. More information and references can be found on the website of our book "Computational Optimal Transport" (see related link below).
会場: via Zoom
イベント公式言語: 英語
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コロキウム
The Epidemiology and Economics of Physical Distancing during Infectious Disease Outbreaks
2022年12月14日(水) 11:00 - 12:30
Prof. Troy Day (Professor, Head of Department, Department of Mathematics and Statistics, Queen's University, Canada)
People's incentives during an infectious disease outbreak influence their behaviour, and this behaviour can impact how the outbreak unfolds. Early on during an outbreak, people are at little personal risk of infection and hence may be unwilling to change their lifestyle to slow the spread of disease. As the number of cases grows, however, people may then voluntarily take extreme measures to limit their exposure. Political leaders also respond to the welfare and changing desires of their constituents, through public health policies that themselves shape the course of the epidemic and its ultimate health and economic repercussions. In this talk I will use ideas from the study of differential games to model how individuals’ and politicians’ incentives change during an outbreak, and the epidemiological and economic consequences that ensue when these incentives are acted upon. Motivated by the COVID-19 pandemic, I focus on physical distancing behaviour and the imposition of stay-at-home orders by politicians. I show that there is a fundamental difference in the political, economic, and health consequences of an infectious disease outbreak depending on the degree of asymptomatic transmission. If transmission occurs primarily by asymptomatic carriers, then politicians will be incentivized to impose stay-at-home orders earlier and for longer than individuals would like. Despite such orders being unpopular, however, they ultimately benefit all individuals. On the other hand, if the disease is transmitted primarily by symptomatic infections, then individuals are incentivized to stay at home earlier and for longer than politicians would like. In this case, politicians will be incentivized to impose back-to-work orders that, despite being unpopular, will again ultimately be to the benefit of all individuals. This is joint work with David McAdams, Fuqua School of Business and Economics Department, Duke University.
会場: via Zoom
イベント公式言語: 英語
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コロキウム
From the Black Hole Conundrum to the Structure of Quantum Gravity
2022年7月26日(火) 15:30 - 17:00
野村 泰紀 (Director, Berkeley Center for Theoretical Physics, University of California, Berkeley, USA)
Having a complete quantum theory of gravity has long been a major goal of theoretical physics. This is because a naive merger of quantum mechanics and general relativity — though it works in certain limited regimes — suffers from major theoretical problems. A particularly acute one arises when one considers the quantum mechanics of black holes: two fundamental principles of modern physics — the conservation of probability in quantum mechanics and the equivalence principle of general relativity — seem to be incompatible with each other. I will explain how recent theoretical progress begins to address this problem and portray the emerging picture of how spacetime and gravity behave at the level of full quantum gravity.
会場: 理化学研究所 和光キャンパス RIBF棟 2階 大会議室 / via Zoom
イベント公式言語: 英語
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コロキウム
第20回 MACSコロキウム
2022年7月8日(金) 15:00 - 18:00
森 哲 (京都大学 大学院理学研究科 生物科学専攻 准教授)
御手洗 菜美子 (Associate Professor, Niels Bohr Institute, University of Copenhagen, Denmark)15:00-16:00 森 哲博士 「餌の毒で身を守るヘビ：２つの毒器官を持つヤマカガシ」 16:15-17:15 御手洗 菜美子博士「いつ誰が「眠る」か？細菌の成長と休眠」 17:15-18:00 継続討論会
会場: via Zoom
イベント公式言語: 日本語
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コロキウム
How is turbulence born: Statistical mechanics and ecological collapse in transitional fluids
2022年4月22日(金) 15:00 - 16:30
Dr. Hong-Yan Shih (Assistant Research Fellow, Institute of Physics, Academia Sinica, Taiwan)
The onset of turbulence is ubiquitous in daily life and is important in various industrial applications, yet how fluids become turbulent has remained unsolved for more than a century. Recent experiments in pipe flow finally quantified this transition, showing that non-trivial statistics and spatiotemporal complexity develop as the flow velocity is increased. Combining numerical simulations of the hydrodynamics equations and an effective theory from statistical mechanics, we discovered the surprising fact that fluid behavior at the transition is governed by the emergent predator-prey dynamics, leading to the mathematical prediction that the laminar-turbulent transition is analogous to an ecosystem on the edge of extinction. This prediction demonstrates that the laminar-turbulent transition is a non-equilibrium phase transition in the directed percolation universality class, and provides a unified picture of transition to turbulence in various systems. I will also show our recent progresses on transitional turbulence, including how an extended ecological model with energy balance successfully recapitulates the spatiotemporal patterns beyond the critical point, and the determination of the critical behavior and an emergent novel phase under interactions in the experimental collaboration.
会場: via Zoom
イベント公式言語: 英語
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コロキウム
第19回 MACSコロキウム・2022年度MACS学生説明会
2022年4月18日(月) 15:00 - 17:40
井上 康博 (京都大学 大学院工学研究科 マイクロエンジニアリング専攻 教授)
15:00- 井上 康博 博士 「形態形成の多細胞力学シミュレーション」 16:05- 2022年度MACS学生説明会 17:10- 各スタディグループの個別説明
会場: via Zoom
イベント公式言語: 日本語
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コロキウム
第18回 MACSコロキウム
2022年2月14日(月) 15:00 - 17:30
長田 哲也 (京都大学 大学院理学研究科 物理学・宇宙物理学専攻 宇宙物理学教室 教授)
15:00- 長田 哲也 博士 「赤外線天文学と数理－不如楽之者」 16:05- 2021年度MACS成果報告会 16:30- 各スタディグループの意見交換
会場: via Zoom
イベント公式言語: 日本語
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コロキウム
第17回 MACSコロキウム
2021年11月19日(金) 15:00 - 18:00
早水 桃子 (早稲田大学 理工学術院 基幹理工学部 講師 (専任) / 国立研究開発法人科学技術振興機構 (JST) さきがけ研究者)
倉谷 滋 (理化学研究所 開拓研究本部 (CPR) 倉谷形態進化研究室 主任研究員 / 理化学研究所 生命機能科学研究センター (BDR) 形態進化研究チーム チームリーダー)15:00- 早水 桃子 博士 「進化の系統樹と系統ネットワークに関する組合せ論」 16:15- 倉谷 滋 博士「進化と発生のパターンについて」 17:15- 継続討論会
会場: via Zoom
イベント公式言語: 日本語
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コロキウム
High-Energy Neutrino Astrophysics in the Multimessenger Era
2021年10月28日(木) 15:00 - 16:30
村瀬 孔大 (Associate Professor, Pennsylvania State University, USA)
The discovery of high-energy cosmic neutrinos opened a new window of astroparticle physics. Their origin is a new mystery in the field, which is tightly connected to the long-standing puzzle about the origin of cosmic rays. I will give an overview of the latest results on high-energy neutrino and cosmic-ray observations, and demonstrate the power of "multimessenger" approaches. In particular, I will show that the observed fluxes of neutrinos, gamma rays, and extragalactic cosmic rays can be understood in a unified manner. I will also highlight the recent developments about astrophysical neutrino emission from supermassive black holes and violent transient phenomena. Possibilities of utilizing high-energy neutrinos as a probe of heavy dark matter may be discussed.
会場: via Zoom
イベント公式言語: 英語
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コロキウム
Finding Gravitational Waves from the Early Universe
2021年9月27日(月) 16:00 - 17:30
小松 英一郎 (Director, Max Planck Institute for Astrophysics, Germany)
The Cosmic Microwave Background (CMB) gives a photographic image of the Universe when it was still an “infant”. We have been using it to test our ideas about the origin of the Universe. The CMB research told us a remarkable story: the structure we see in our Universe such as galaxies, stars, planets, and eventually ourselves originated from tiny quantum fluctuations in the period of the early Universe called cosmic inflation. While we have accumulated strong evidence for this picture, the extraordinary claim requires extraordinary evidence. The last prediction of inflation that is yet to be confirmed is the existence of primordial gravitational waves whose wavelength can be as big as billions of light years. To this end we have proposed to JAXA a new satellite mission called LiteBIRD, whose primary scientific goal is to find signatures of gravitational waves in the polarisation of the CMB. In this presentation we describe physics of gravitational waves from inflation, and the LiteBIRD proposal.
会場: via Zoom
イベント公式言語: 英語
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コロキウム
Quantitative Population Dynamics in Interdisciplinary Biology
2021年7月8日(木) 10:30 - 12:00
岩見 真吾 (名古屋大学 大学院理学研究科 教授)
Through the course of life, from the moment of birth till death, an organism will achieve various states of equilibrium or ‘homeostasis’ which will inevitably encounter perturbations. The processes of cell growth, differentiation, infection, mutation, evolution and adaptation work together as a coordinated ‘system’, described by mathematical models for population dynamics, to maintain a healthy state. Any disruptions to this system leads to disease including infection, allergy, cancer, and aging. We are conducting interdisciplinary research to elucidate “Quantitative Population Dynamics” through the course of life with original mathematical theory and computational simulation, which are both our CORE approach. Our mathematical model-based approach has quantitatively improved a current gold-standard approach essentially relying on the statistical analysis of “snapshot data” during dynamic interaction processes in life sciences research. In this talk, I will explain how our interdisciplinary approach extends our understanding for complicated clinical data and apply real world problem with an example of the Novel Coronavirus Disease, COVID-19.
会場: via Zoom
イベント公式言語: 英語
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コロキウム
第16回 MACSコロキウム
2021年7月5日(月) 15:00 - 18:00
谷村 吉隆 (京都大学 大学院理学研究科 化学専攻 教授)
西森 秀稔 (数理創造プログラム 客員主管研究員 / 東京工業大学 特任教授)15:00- 谷村 吉隆 博士 「生物化学物理を支配する非平衡量子統計力学」 16:15- 西森 秀稔 博士 「量子アニーリングを用いた量子系のシミュレーション」 17:15- 継続討論会
会場: via Zoom
イベント公式言語: 日本語
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コロキウム
第15回 MACSコロキウム・2021年度MACS学生説明会
2021年4月23日(金) 15:00 - 17:30
石川 博 (早稲田大学 理工学術院 基幹理工学部 情報理工学科 教授)
15:00- 石川 博 博士「機械に認識させるとはどういうことか」 16:05- 2021年度MACS学生説明会
会場: via Zoom
イベント公式言語: 日本語
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コロキウム
Mirror symmetry and KAM theory
2021年4月16日(金) 13:30 - 15:00
深谷 賢治 (Permanent Member, Simons Center for Geometry and Physics, Stony Brook University, New York, USA)
13:30pm-15:00pm (JST) Mirror symmetry is a phenomenon discovered in String theory and is much discussed recently in mathematics especially in the field of complex (algebraic) geometry and symplectic geometry. Strominger-Yau-Zaslow found that this phenomenon is closed related to a Lagrangian torus fibration. In an integrable system in Hamiltonian dynamics, the phase space is foliated by Lagrangian tori. I would like to explain a program that the Lagrangian torus fibration found by Strominger-Yau-Zaslow could be regarded as one appearing certain integrable system and KAM theory (which describes a amiltonian dynamics that is a perturbation of an integrable system) could appear in the situation of Mirror symmetry.
会場: via Zoom
イベント公式言語: 英語
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コロキウム
第14回 MACSコロキウム・2020年度MACS成果報告会
2021年2月17日(水) 15:00 - 17:30
金子 善宏 (京都大学 大学院理学研究科 地球惑星科学専攻 地球物理学教室 准教授)
15:00- 金子 善宏 博士「数値シミュレーションで地震現象の謎に迫る」 16:05- 2020年度MACS成果報告会 16:30- 各スタディグループの意見交換
会場: via Zoom
イベント公式言語: 日本語
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コロキウム
Geometry (形); Inconspicuous regulator that determines the fate of cells
2020年12月14日(月) 10:00 - 11:30
Prof. Sungrim Seirin-Lee (広島大学 教授)
December 14 at 10:00-11:30, 2020 (JST) December 13 at 20:00-21:30, 2020 (EST) In the history of mathematical study in pattern formation, the effect of domain has been considered as an important factor that can regulate spatial patterning. However, it is still unknown in biology how the geometry of the domain such as nuclear or cellular shapes can directly regulate the cell fate. In this talk, I will introduce two studies of spatial reorganization in chromatin and cellular dynamics and show that the domain is likely to play a critical role in determining the cell function.
会場: via Zoom
イベント公式言語: 英語
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コロキウム
The Unreasonable Effectiveness of Quantum Theory in Mathematics
2020年11月26日(木) 10:00 - 11:30
Prof. Robbert Dijkgraaf (Director, Institute for Advanced Study in Princeton, USA)
November 26 at 10:00-11:30, 2020 (JST) November 25 at 20:00-21:30, 2020 (EST) The physical concepts of quantum theory, in particular of quantum gravity and string theory, have proven to be extremely powerful in addressing deep problems in pure mathematics, from knot invariants to algebraic geometry. Is there such a thing as “quantum mathematics”? Should we add Feynman diagrams, strings, branes and black holes to the language of mathematics?
会場: via Zoom
イベント公式言語: 英語
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コロキウム
第13回 MACSコロキウム
2020年11月13日(金) 15:00 - 18:00
川口 真也 (京都大学 大学院理学研究科 生物科学専攻 生物物理学教室 高次情報形成学講座 教授)
杉田 有治 (数理創造プログラム 上級研究員 / 理化学研究所 開拓研究本部 (CPR) 杉田理論分子科学研究室 主任研究員)15:00- 川口 真也 博士「神経系のやわらかい情報処理」 16:15- 杉田 有治 博士「計算機シミュレーションで細胞の中を観る」 17:15- 継続討論会
会場: via Zoom
イベント公式言語: 日本語
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コロキウム
第12回 MACSコロキウム・2020年度MACS学生説明会
2020年7月17日(金) 15:00 - 18:30
平岡 裕章 (京都大学 高等研究院 (KUIAS) 教授 / 理化学研究所 革新知能統合研究センター (AIP) トポロジカルデータ解析チーム チームリーダー)
田中 求15:00- 平岡 裕章 博士「トポロジカルデータ解析：理論と応用」 16:15- 令和2年度 MACS 学生説明会 17:30- 田中 求 博士「臨床医学の課題に切り込む数物科学」
会場: via Zoom
イベント公式言語: 日本語
48 イベント