The ultimate goal of this project is to clarify the birth and evolution of the Universe via the observation and the theory of fundamental physics.
Over the last decade, cosmological observations using new technologies have greatly developed, and our fundamental view of the Universe has been significantly progressed. One important milestone has been the establishment of a "concordant cosmological model" that emerged a few years ago, based on the measurements of cosmic microwave backgrounds and the observation of large-scale structure of the Universe. The concordant cosmological model can explain many observational facts, and it consistently describes the dynamics of the cosmic expansion and the structure formation of the Universe. On the other hand, the great success of this model highlights various fundamental problems that cannot be clearly answered at present. Among these, the origin of dark energy, which accounts for 70 % of the energy density of the Universe and explains the late-time cosmic acceleration discovered recently, is one of the most challenging problem in cosmology and fundamental physics.
In order to deeply understand the Universe and to clarify the nature of dark energy, it is important to develop the top-down approach based on the theory of fundamental physics to construct a consistent scenario for cosmic history from the early universe to the observed universe. Also, the bottom-up approach to precisely reveal the current status of the Universe through the observational data is indispensable.