|Speaker:||Fuminobu Takahashi (IPMU)|
|Title:||Another dark component of the Universe|
|Date (JST):||Thu, Jan 13, 2011, 13:00 - 14:00|
|Place:||Seminar Room A|
Recent cosmological observations, such as the measurement of the primordial 4He abundance, CMB, and large scale structure,
give slight preference to the existence of extra radiation component. The extra radiation may be accounted for by particles which
were in thermal equilibrium and decoupled before the big bang nucleosynthesis. We discuss several candidates and propose a
model which can be tested at the collider experiments.