theoretical astrophysics
theory of stellar oscillation, asteroseismology
Pulsating variable stars are those stars that periodically undergo deformation and change their luminosity.
Because those stars provide more information than normal stars with constant luminosity, they can be used to
study in detail the internal structure and the evolution of the stars. Moreover, accumulation of the properties of each pulsating star leads to those of the group of the stars, and hence contributes to our understanding of the chemical and dynamical structure of the Galaxy. The research topics include theoretical understanding of the pulsating variable stars (physical mechanism and mathematical structure) and the diagnostics of the stellar interior based on the oscillation (asteroseismology).
http://seismology.astron.s.u-tokyo.ac.jp/