Seminar

Geometry in condensed matter physics

April 8 (Sat) at 13:00 - 14:00, 2017

Naoto Nagaosa (Deputy Director, Group Director, Strong Correlation Theory Research Group, RIKEN Center for Emergent Matter Science (CEMS) / Professor, Department of Applied Physics, Graduate School of Engineering, The University of Tokyo)

Quantum geometry plays essential roles current condensed matter physics. Aharonov-Bohm effect and Berry phase as its generalization are the key concepts in electronic systems in solids, which are described by the Bloch wavefunctions and electron correlation effects on top of them. In this talk, I will describe how the geometry determines the physical properties of materials focising on the gauge structure and electomagnetic responses.

Venue: Seminar Room #160

Event Official Language: English

The local time of simple random walks and Gaussian free fields in two dimensions

April 6 (Thu) at 10:30 - 11:30, 2017

Izumi Okada

By using the method of probability analysis, we have researched the local time of a multidimensional-simple random walk. Note that the local time means the number of visits of a simple random walk to specific points in integer lattice. It is known that functionals of a local time and Gaussian free fields denote a variety of nonlinear and mathematical phenomena such as random media. Then, we are observing the relationship between two processes. As a first step, we especially observe favorite points (the singular sites where the local time is large) et al. By A.Dembo, Y.Peres, O.Zeitouni, J.Rosen, who are leading experts in this field, the importance of this point has been recently shown.

Venue: Seminar Room #160

Event Official Language: English

Fatgraph models for RNA molecules

March 23 (Thu) at 10:30 - 11:30, 2017

Hiroyuki Fuji (Associate Professor, Faculty of Education, Kagawa University)

Concepts of fatgraphs and partial chord diagrams occur in many branches of mathematics, including topology, geometry, and representation theory. During the last decade, some applications of these mathematical objects to the research of the molecular biology have been reported. Among them, in particular, a characterization by the genus in the fatgraph presentation of the RNA has been studied remarkably. In this talk, I will explain how the concepts of fatgraphs and partial chord diagrams are applied to the study of the secondary structure of the RNA with pseudoknots, and introduce the matrix model that is invented by basic techniques of the quantum field theory. If time permits, I shall discuss about the matrix model of the protein, and speculate about further developments.

Venue: Seminar Room #160

Event Official Language: English

T-DUALITY AND SCATTERING OF STRINGY STATES

December 12 (Mon) at 15:00 - 16:00, 2016

Jnan Maharana

I shall first review the salient features of T-duality, paying special attentions to the worldsheet perspective. The construction of vertex operators for Moduli will be discussed. The KLT formalism will be applied to show that the S-matrix for scattering of massless state arising from toroidal compactification of closed bosonic string is T-duality invariant.

Venue: Seminar Room #160

Event Official Language: English

Non-perturabative quantum analysis based on resurgence theory

November 11 (Fri) at 10:30 - 11:30, 2016

Tatsuhiro Misumi (Lecturer, Akita University)

Venue: Seminar Room #160

Event Official Language: Japanese