Structure Formation

There are rich structures in the present-day universe, such as stars, galaxies, and large-scale structure. We study how these objects are formed using large computer simulations and sophisticated theoretical models.

The standard Big Bang model posits that the universe was nearly homogeneous and very hot when it was born. Tiny “ripples” in the distribution of matter were generated through a rapid expansion phase called inflation in the very early universe. These primeval density fluctuations grew by the action of gravity, eventually forming luminous objects such as galaxies.

The energy content of the universe and basic statistic that describe the condition of the early universe have been determined with great accuracy from recent observations of cosmic microwave background radiation, large-scale galaxy distribution and distant supernovae. Cosmology is now at a stage where theory can make solid predictions, whereas a broad class of observations can be directly used to verify them. Planned large astronomical surveys such as Sloan Digital Sky Survey III and Subaru Hyper Sprime-Cam Survey will provide rich information on the nature of dark matter and dark energy. Accurate theoretical predictions are needed to make the full use of the observational data.

Our primary interests are in primordial star formation in the early universe, the formation and evolution of galaxies, and the formation of large-scale structure. Results from these studies will be used for making good plans and proposals for Subaru-HSC/PFS dark energy survey.

Group Members