E. P. Berni Ann Thushari, Riou Nakamura, Mikio Ikeda, Masa-aki Hashimoto
We re-investigate the cosmic thermal evolution with a cosmological term which
decay into photon. We assume that the cosmological term is a function of the
scale factor that increases toward the early universe. We put on the
constraints from recent type Ia supernovae (SNIa) by Union-2 compilation and
the cosmic microwave background (CMB) temperature at $0.02 < z < 3$. From SNIa,
we find that the effects of a decaying cosmological term on the cosmic
expansion rate should be very small at $z < 1.5$.
On the other hand, we obtain the severe constraints for parameters from the
CMB temperature observations. This results mean the temperature can be still
lower than the case of the standard cosmological model. Its should only affect
the thermal evolution at the earlier epoch. Therefore we need to do analysis
precisely such as the newest WMAP observational data.
View original:
http://arxiv.org/abs/1112.2911
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