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Relative and equivariant Lagrangian Floer homology and Atiyah-Floer conjecture

June 19 (Tue) 14:30 - 16:00, 2018

Kenji Fukaya (Senior Visiting Scientist, RIKEN Interdisciplinary Theoretical and Mathematical Sciences Program (iTHEMS) / Permanent Member, Simons Center for Geometry and Physics, Stony Brook University, New York, USA)

Atiyah-Floer conjecture concerns a relationship between Floer homology in Gauge theory and Lagrangian Floer homology. One of its difficulty is that the symplectic manifold on which we consider Lagrangian Floer homology is in general singular. In this talk I will explain that, by using relative and equivariant version of Lagrangian Floer homology, we can resolve this problem and can at least state the conjecture as rigorous mathematical conjecture. Supported by RIKEN iTHEMS and Tuesday Seminar on Topology (Graduate School of Mathematical Sciences, The University of Tokyo).

Venue: Room 056, Graduate School of Mathematical Sciences, The University of Tokyo

Event Official Language: Japanese

On the interplay between intrinsic and extrinsic instabilities of spatially localized patterns

June 7 (Thu) 15:00 - 16:30, 2018

Yasumasa Nishiura (Professor, Advanced Institute for Materials Research (AIMR), Tohoku University)

Spatially localized dissipative structures are observed in various fields, such as neural signaling, chemical reactions, discharge patterns, granular materials, vegetated landscapes, binary convection and block copolymer nanoparticles. These patterns are much simpler than single living cells, however they seem to inherit several characteristic “living state” features, such as generation of new patterns, self-replication, switching to new dynamics via collisions and adaptive morphological changes to environments. These behaviors stem from an interplay between the intrinsic instability of each localized pattern and the strength of external signals. To understand such an interplay, we explore the global geometric interrelation amongst all relevant solution branches of a corresponding system with approximate unfolding parameters. For instance, it has been uncovered that large deformation via strong collision is mapped into the network of unstable patterns in infinite dimensional space, and that an organizing center for 1D pulse generators is a double homoclinicity of butterfly type. Large deformation of patterns is unavoidable so that a global geometric structure formed by all relevant solution branches gives us much more insight rather than conventional PDE approaches. We illustrate the impact of this approach for the case of pulse generators. We also report on the recent exciting finding, namely the formation of exotic 3D nanoparticles of block copolymers caused by the interplay between internal repulsion and affinity to external solvent, which is consistent with experimental results.

Venue: Nishina Hall

Broadcast:#305-2, Computational Science Research Building / SUURI-COOL (Kyoto)

Event Official Language: English

iTHEMS Science Outreach Workshop 2018

June 1 (Fri) - 4 (Mon) 2018

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 from last year to establish better science communication. Contact: Takashi Tsuboi (iTHEMS Deputy Director)

Venue: Tambara Institute of Mathematical Sciences, The University of Tokyo

Event Official Language: Japanese

Nerd Nite Tokyo

May 11 (Fri) 20:00 - 22:00, 2018

Catherine Beauchemin (Senior Visiting Scientist, RIKEN Interdisciplinary Theoretical and Mathematical Sciences Program (iTHEMS) / Professor, Department of Physics, Ryerson University, Canada)

Nerd Nite is "the Discovery Channel with beer", a worldwide monthly event series that mixes presentations, performances, trivia, demos, music, and of course drinking. Nerd Nite Tokyo events are held in English. This time, Dr. Catherine Beauchemin (iTHEMS senior visiting scientist) will give a 20min. talk on the problems of being a physicist in the world of virology. Fee: 1000 JPY per person

Venue: Nagatacho GRID (2-5-3 Hirakawa-cho, Chiyoda-ku, Tokyo 102-0093)

Event Official Language: English

Numerical analysis of point vortex dynamics by the method of fundamental solutions

April 17 (Tue) 16:00 - 17:30, 2018

Koya Sakakibara (Program-Specific Assistant Professor, Graduate School of Science, Kyoto University)

iTHEMS / KUAMS Joint Seminar

Venue: Maskawa Hall, 1F, Maskawa Building for Education and Research

Event Official Language: Japanese

iTHEMS Mini-workshop/ Theoretical Biology Mini-workshop

October 19 (Thu) 14:00 - 17:00, 2017

“Kazusa DNA Research Institute: Who is this?” Dr. Satoshi Tabata (Kazusa DNA Res Inst, Director) “Did the journey to strawberry start from Japan?” Dr. Sachiko Isobe (Kazusa DNA Res Inst, Lab Head) Strawberry (Fragaria × ananassa) is cultivated and consumed across the world. It is an allo-polyploidy species (2n = 8X = 56) with an estimated genome size of 1C = 708–720 Mb. Strawberry was artificially generated in the 16th century Europe, by crossing between two octoploid species, F. chiloensis and F. virginiana. The evolutionary origin and genome structure have been discussed and not fully determined. The first proposed structure was AABBBBCC model (Federova, 1946), then, Senanayake and Bringhurst (1967) proposed AAA’A’BBBB model. The fully allopolyploidy structure (AAA’A’BBB’B’) was suggested by Bringhurst in 1990 based on isozyme segregation. This model was also supported by the segregation patterns of CAPS markers (Kunihisa et al. 2011) and SSR markers (Isobe et al. 2013). However, just recently, Tennessen et al. (2014) proposed the AvAvBiBiB1B1B2B2, model, according to the results of targeted DNA capture and sequencing by using next generation sequencing (NGS) technology. In this model, Av represents the most F. vesca like genome, while Bi represents the most F, iinmae like genome. The origin of F. vesca is considered as North America, and F. iinumae is an endemic species in Japan. Our resent results of denovo whole genome sequencing support the AvAvBiBiB1B1B2B2 model, that suggest considerable part of the strawberry genome showed the highest similarity with F. iinumae.

Event Official Language: English

Braids and topological mixing

June 26 (Mon) 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) 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

Deep learning and physics

June 5 (Mon) 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