Paper: astro-ph/0511821
Date: Wed, 30 Nov 2005 11:56:13 GMT (55kb)

Title: Dark Energy Evolution and the Curvature of the Universe from Recent
Observations

Authors: Kazuhide Ichikawa and Tomo Takahashi

Comments: 17 pages, 12 figures
\\
We discuss the constraints on the time-varying equation of state for dark
energy and the curvature of the universe using observations of type Ia
supernovae from Riess et al. and the most recent Supernova Legacy Survey
(SNLS), the baryon acoustic oscillation peak detected in the SDSS luminous red
galaxy survey and cosmic microwave background. Due to the degeneracy among the
parameters which describe the time dependence of the equation of state and the
curvature of the universe, the constraints on them can be weakened when we try
to constrain them simultaneously, in particular when we use a single
observational data. However, we show that we can obtain relatively severe
constraints when we use all data sets from observations above even if we
consider the time-varying equation of state and do not assume a flat universe.
We also found that the combined data set favors a flat universe even if we
consider the time variation of dark energy equation of state.

\\ ( http://arXiv.org/abs/astro-ph/0511821 , 55kb)