Eur. Phys. J. C (2012) 72: 2260
https://doi.org/10.1140/epjc/s10052-012-2260-2

Regular Article - Theoretical Physics

Equation-of-state formalism for dark energy models on the brane and the future of brane universes

¹ Department of Theoretical Physics, Baltic Federal University of I. Kant, 236041, 14 Nevsky St., Kaliningrad, Russia
² Consejo Superior de Investigaciones Científicas, ICE/CSIC and IEEC Campus UAB, Facultat de Ciències, Torre C5-Par-2a pl, 08193, Bellaterra, Barcelona, Spain
³ Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain

^* e-mail: elizalde@ieec.uab.es
^** e-mail: elizalde@math.mit.edu

Received: 25 September 2012
Revised: 27 November 2012
Published online: 28 December 2012

Abstract

Brane dark energy cosmologies, leading to various possible evolutions of our universe, are investigated. The discussion shows that while all these models can be made arbitrarily close to the standard ΛCDM cosmology at present, their future evolutions can be very different, even diverge with time in a number of ways. This includes asymptotic de-Sitter evolution, Little Rip with dissolution of bound structures, and various possible singularities, as the Big Rip, a sudden future singularity (Type II), and Type III and Type IV cases. Specifically, some interesting effects coming from the brane tension are investigated. It is shown, in particular, that the Little Rip occurs faster on the brane model than in usual FRW cosmology. In the asymptotic de-Sitter regime the influence of the brane tension leads to a deviation of the value of the effective cosmological constant from that corresponding to ordinary dark energy. As a consequence, the value of the inertial force from the accelerating expansion can greatly exceed the corresponding inertial force in ordinary cosmological models.