Paper: astro-ph/0510006
Date: Fri, 30 Sep 2005 19:52:48 GMT (14kb)

Title: Coincidence Problem in an Oscillating Universe

Authors: Guangcan Yang and Anzhong Wang

Categories: astro-ph

Comments: latex, 3 figures, to appear in Gen. Relativ. Grav
\\
We analyze an oscillating universe model in brane world scenario. The
oscillating universe cycles through a series of expansions and contractions and
its energy density is dominated by dust matter at early-time expansion phase
and by phantom dark energy at late-time expansion phase. We find that the
period of the oscillating universe is not sensitive to the tension of the
brane, but sensitive to the equation-of-state parameter $w$ of the phantom dark
energy, and the ratio of the period to the current Hubble age approximately
varies from 3 to 9 when the parameter $w$ changes from -1.4 to -1.1. The
fraction of time that the oscillating universe spends in the coincidence state
is also comparable to the period of the oscillating universe. This result
indicates that the coincidence problem can be significantly ameliorated in the
oscillating universe without singularity.

\\ ( http://arXiv.org/abs/astro-ph/0510006 , 14kb)