Three Components Evolution in a Simple Big Bounce Cosmological Model

Abstract

We consider a five-dimensional Ricci flat Bouncing cosmology and assume that the four-dimensional universe is permeated smoothly by three minimally coupled matter components: CDM+baryons $\rho_{m}$, radiation $\rho_{r}$ and dark energy $\rho_{x}$. Evolutions of these three components are studied and it is found that dark energy dominates before the bounce, and pulls the universe contracting. In this process, dark energy decreases while radiation and the matter increase. After the bounce, the radiation and matter dominates alternatively and then decrease with the expansion of the universe. At present, the dark energy dominates again and pushes the universe accelerating. In this model, we also obtain that the equation of state (EOS) of dark energy at present time is $w_{x0}\approx -1.05$ and the redshift of the transition from decelerated expansion to accelerated expansion is $z_{T}\approx 0.37$, which are compatible with the current observations.