Connections of Pair Correlations to Equidistribution and Additive Energy

August 31 (Thu) at 13:30 - 15:00, 2017

Thomas Lachmann (Graz University of Technology, Austria)

Venue: Common Room #246-248

Event Official Language: English

Pulsar Winds: Ultimate Relativistic Outflows

August 29 (Tue) at 13:30 - 14:30, 2017

Dmitry Khangulyan (Rikkyo University)

A highest density body that features the strongest magnetic field launches, no surprise, an ultimate outflow -- pulsar wind. Despite their relativistic nature and complexity, a few simple analogies can help us to understand the essence of pulsar physics. I will present several links connecting basic mechanics and electrodynamics, every-day thermodynamics and hydrodynamics to the processes taking place in the vicinity of pulsars. These fundamental relations not only provide a simple mental image for the pulsar physics but also have their imprint in high-energy data obtained from pulsars and pulsar wind nebulae.

Venue: #433, Main Research Building

Event Official Language: English

"Nihon Shoki" Classification Theory

August 24 (Thu) at 15:00 - 17:30, 2017

Hiromichi Mori (Professor, Kyoto Sangyo University)

Venue: Okochi Hall

Event Official Language: Japanese

Introduction to topological quantum computing

July 28 (Fri) at 15:00 - 16:30, 2017

Zhenghan Wang (University of California Santa Barbara, USA)

The 22nd iTHES Theoretical Science Colloquium Topological quantum computing is a paradigm to build a quantum computer with topological phases of matter. Majorana physics is the best example of topological physics besides quantum Hall. I will give an introduction to building a topological quantum computer with Majorana zero modes.

Venue: Suzuki Umetaro Hall

Event Official Language: English

Knot Theory (6th)

July 26 (Wed) at 10:30 - 11:30, 2017

Yuka Kotorii (Postdoctoral Researcher, Mathematical Analysis Team, RIKEN Center for Advanced Intelligence Project (AIP))

Venue: Seminar Room #160

Event Official Language: English

Knot Theory (5th)

July 24 (Mon) at 10:30 - 11:30, 2017

Yuka Kotorii (Postdoctoral Researcher, Mathematical Analysis Team, RIKEN Center for Advanced Intelligence Project (AIP))

Venue: Seminar Room #160

Event Official Language: English

Joint Seminar with Condensed Matter Theory Laboratory

July 20 (Thu) at 13:30 - 15:00, 2017

Shinsei Ryu (Associate Professor, Department of Physics and the College, The University of Chicago, USA)

Venue: #435-437, Main Research Building

Event Official Language: English

An invitation to number theory

July 10 (Mon) at 13:30 - 14:30, 2017

Hiroyasu Miyazaki

The goal of number theory is to reveal the mystery of natural numbers 1,2,3…. It has a long history, and it is still developing by exchanging ideas with many other branches of mathematics. In the long history, number theory had been thought of as a pure mathematics with no direct application outside mathematics. However, the rapid development of computer science changed the situation: the theory of prime numbers has been applied to code theory, cryptography, random number generation etc. It seems that there are several researches in physics and biology using the method of number theory, too. The aim of this talk is to give a beginner-friendly introduction to number theory. Among many topics, I will focus on very fundamental and important concepts: the “p-adic numbers” and the “finite fields.” I hope that this talk will motivate you to relate your research to number theory.

Venue: Seminar Room #160

Event Official Language: English

Braids and topological mixing

June 26 (Mon) at 14:00 - 15:00, 2017

Eiko Kin (Osaka University)

In mathematics, the braids are important tools for the knot theory, hyperbolic geometry, and dynamical systems etc. In the last ten years, the braids have been used to study mixing in fluids. Various simple mixing devices (e.g. taffy machines) have been developed. These devices utilize a particular type of braid, so-called a pseudo-Anosov type. The notion of pseudo-Anosov braids comes from the Nielsen-Thurston theory on the surface automorphisms, and the theory says that the devices using pseudo-Anosov braids are "efficient" in some sense. In this lecture, I will give a quick introduction of the Nielsen-Thurston theory and the classification of braids. I will give a picture of the "complexity" forced by pseudo-Anosov braids. In particular, I will explain why pseudo-Anosov braids are useful and why they can be used to build interesting mixing devices. Cosponsored by RIKEN iTHEMS and AIP Mathematical Science Team

Venue: RIKEN Tokyo Liaison Office (Nihonbashi)

Event Official Language: English

Homological algebra, Renormalization and Transversality

June 26 (Mon) at 10:30 - 11:30, 2017

Kenji Fukaya (Permanent Member, Simons Center for Geometry and Physics, Stony Brook University, New York, USA)

Transversality is a basic concept of differential topology and theory of manifold. Homological algebra may be regarded as a method to approximate `spaces' by an algebra and is a basic concept in agebraic topology. I would like to explain in this talk how they are related to some basic problem of quantum field theory such as renormalization. Cosponsored by RIKEN iTHEMS and AIP Mathematical Science Team

Venue: RIKEN Tokyo Liaison Office (Nihonbashi)

Event Official Language: English

Interdisciplinary symposium on modern density functional theory

June 19 (Mon) - 23 (Fri), 2017

Density functional theory (DFT) is one of the most widely used methods for quantum many-body problems in condensed matter, nuclear physics, and quantum chemistry. Although we share similar theoretical frameworks and computational techniques, we sometimes use quite different languages, which sets a certain barrier for efficient interdisciplinary collaborations on modern DFT, in particular, that powered by High Performance Computing Infrastructure (HPCI). The key idea of this symposium is to have intensive interdisciplinary discussions and to initiate a new collaboration platform, in particular, by introducing the basic methodology and highlighting the latest hot topics in the fields condensed matter, nuclear physics, and quantum chemistry. iTHEMS-AICS-RNC-U.Tokyo joint symposium

Venue: Okochi Hall

Event Official Language: English

Knot Theory (4th)

June 16 (Fri) at 10:30 - 11:30, 2017

Yuka Kotorii (Postdoctoral Researcher, Mathematical Analysis Team, RIKEN Center for Advanced Intelligence Project (AIP))

Venue: Seminar Room #160

Event Official Language: English

Knot Theory (3rd)

June 14 (Wed) at 10:30 - 11:30, 2017

Yuka Kotorii (Postdoctoral Researcher, Mathematical Analysis Team, RIKEN Center for Advanced Intelligence Project (AIP))

Venue: Seminar Room #160

Event Official Language: English

iTHEMS Science Outreach Workshop 2017

June 9 (Fri) - 12 (Mon), 2017

This is a workshop in which researchers in natural and mathematical sciences and the science journalists get together and discuss outreach activities. iTHEMS started to support this annual workshop as well as the journalist in residence program to establish better science communication.

Event Official Language: Japanese

Galois representations and the Langlands correspondence

June 8 (Thu) at 13:30 - 14:30, 2017

Kazuki Tokimoto (Kyoto University)

The Langlands correspondence relates number-theoretic objects to completely different objects. While still largely conjectural, it has attracted interests of many mathematicians over the years. It is known that the local Langlands correspondence in a special case can be constructed in a geometric way (the non-abelian Lubin-Tate theory). In this talk, I will explain some basic concepts in mathematics (such as groups, representations and Galois groups) and then try to convey some flavor of my result related to the non-abelian Lubin-Tate theory.

Venue: Seminar Room #160

Event Official Language: English

Deep learning and physics

June 5 (Mon) at 13:00 - 18:00, 2017

We are happy to announce our 3rd joint symposium of Osaka CTSR, RIKEN iTHES/iTHEMS and Kavli IPMU, focusing this time on the topic of deep learning and its relation to fundamental physics. The rapid and vast applications of deep learning and artificial intelligence can potentially provide a breakthrough in various situations in fundamental physics. Invited speakers will deliver a cutting-edge progress in this interesting and developing fields, and participants are expected to join discussions. In addition, in the morning (9:00-12:00) at Nambu hall, we have an informal lecture course on deep learning by M. Taki (in Japanese). Osaka CTSR - RIKEN iTHES/iTHEMS - Kavli IPMU Joint Symposium

Event Official Language: English

Knot Theory (2nd)

June 1 (Thu) at 10:30 - 11:30, 2017

Yuka Kotorii (Postdoctoral Researcher, Mathematical Analysis Team, RIKEN Center for Advanced Intelligence Project (AIP))

Venue: Seminar Room #160

Event Official Language: English

Atypicality of most few-body observables

May 29 (Mon) at 13:30 - 14:30, 2017

Ryusuke Hamazaki (The University of Tokyo)

Understanding how isolated quantum systems thermalize has recently gathered renewed interest among theorists, thanks to the experimental realizations of such systems. The eigenstate thermalization hypothesis (ETH) is particularly investigated as a sufficient condition for the approach to thermal equilibrium. It states that diagonal matrix elements of an observable for the energy eigenstates are almost the same within a small energy shell. The ETH is justified for an observable and a Hamiltonian whose respective eigenbases are typically oriented to each other; i.e., for almost all unitary transformations of these two eigenbases with respect to the uniform Haar measure. In this seminar, we consider a Hamiltonian with few-body interactions and random observables without assuming the uniform Haar measure. These observables are chosen in an operational manner as random linear combinations of the operator basis of spins. We show that most few-body observables have atypical matrix elements when the energy width is not exponentially small with the system size. Namely, the maximum fluctuation for diagonal matrix elements is larger than that predicted by the uniform Haar measure.

Venue: #433, Main Research Building

Event Official Language: English

Knot Theory (1st)

May 29 (Mon) at 10:30 - 11:30, 2017

Yuka Kotorii (Postdoctoral Researcher, Mathematical Analysis Team, RIKEN Center for Advanced Intelligence Project (AIP))

Venue: Seminar Room #160

Event Official Language: English