Semiclassical methods in mathematical quantum mechanics
 Date
 January 23 (Thu) at 16:00  18:10, 2020 (JST)
 Speaker

 Shu Nakamura (Professor, Gakushuin University)
 Language
 English
Plan of the seminar: we separate each talk into two. In the first 60 minutes the speaker gives an introductory talk for nonmathematicians. After a short break, the second 60 minutes is spent for a bit more detailed talk for mathematicians (working in other areas). We welcome you joining both parts of the seminar or only the first/second half.
Talk 1: Semiclassical analysis, microlocal analysis and scattering theory.
I plan to talk about overview on the semiclassical analysis and related topics, especially its intrinsic relationship with microlocal analysis and (microlocal) scattering theory. Roughly speaking, the microlocal analysis is an application of semiclassical idea to the analysis of singularities, and its analogue in momentum space is the microlocal scattering theory. We discuss basic notions of these, and mention several recent results.
Talk 2: Microlocal structure of the scattering matrix with longrange perturbations.
As an example of topics discussed in Talk 1, we discuss recent results on the scattering matrix with longrange perturbations. In particular, we show that the scattering matrix is expressed as a Fourier integral operator, and in some cases we can decide its spectral properties. Our approach is fairly geometric and abstract, and thus applies not only to usual Schrödinger operators but also to higher order operators and discrete Schrödinger operators.