I am working on Supernovae, which are the stellar explosions at the end of their lives. These are the key events in the evolution of stars, formation of neutron stars and black holes, and origin of heavy elements. Supernovae occur under extreme conditions, whose studies could lead to finding a new physics.　

My current focuses are: 1)Type Ia Supernova Cosmology: These supernovae have revealed the presence of cosmic acceleration and Dark Energy. Clarifying the progenitors and explosion mechanism of these supernovae can contribute to precision cosmology. 2)Evolution and Explosion of First Stars and Cosmic Chemical Evolution: Nucleosynthesis of stars with initially no heavy elements is compared with the chemical abundances of old stars. 3)Gamma-Ray Bursts and Hypernovae: Studied are the production mechanisms of huge explosion energy from black holes and neutron stars. Studies of nucleosynthesis in Hypernovae would clarify the important contribution of hypernovae in the origin of elements.