An analytic model for the transition from decelerated to accelerated cosmic expansion
| dc.creator | de Leon, J. Ponce | |
| dc.date | 2005-11-29 | |
| dc.date | 2006-03-16 | |
| dc.date.accessioned | 2026-07-07T11:26:20Z | |
| dc.date.available | 2026-07-07T11:26:20Z | |
| dc.description | We consider the scenario where our observable universe is devised as a dynamical four-dimensional hypersurface embedded in a five-dimensional bulk spacetime, with a large extra dimension, which is the {\it generalization of the flat FRW cosmological metric to five dimensions}. This scenario generates a simple analytical model where different stages of the evolution of the universe are approximated by distinct parameterizations of the {\it same} spacetime. In this model the evolution from decelerated to accelerated expansion can be interpreted as a "first-order" phase transition between two successive stages. The dominant energy condition allows different parts of the universe to evolve, from deceleration to acceleration, at different redshifts within a narrow era. This picture corresponds to the creation of bubbles of new phase, in the middle of the old one, typical of first-order phase transitions. Taking $Ω_{m} = 0.3$ today, we find that the cross-over from deceleration to acceleration occurs at $z \sim 1-1.5 $, regardless of the equation of state in the very early universe. In the case of primordial radiation, the model predicts that the deceleration parameter "jumps" from $q \sim + 1.5$ to $q \sim - 0.4$ at $z \sim 1.17$. At the present time $q = - 0.55$ and the equation of state of the universe is $w = p/ρ\sim - 0.7 $, in agreement with observations and some theoretical predictions. | |
| dc.description | The abstract and introduction are improved and the discussion section is expanded. A number of references are added | |
| dc.identifier | https://arxiv.org/abs/gr-qc/0511150 | |
| dc.identifier | http://arxiv.org/abs/gr-qc/0511150 | |
| dc.identifier | Int.J.Mod.Phys.D15:1237-1257,2006 | |
| dc.identifier | doi:10.1142/S0218271806008929 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/195790 | |
| dc.subject | General Relativity and Quantum Cosmology | |
| dc.title | An analytic model for the transition from decelerated to accelerated cosmic expansion | |
| dc.type | text |