Chaplygin DGP cosmologies

TL;DR

This paper introduces a new class of braneworld cosmological models based on the generalized Chaplygin gas, which exhibit late-time phantom acceleration without phantom fluids, smoothly transitioning from matter-dominated to accelerated expansion.

Contribution

It presents a novel braneworld model where effective phantom behavior persists at all redshifts, based on the generalized Chaplygin gas, avoiding future singularities.

Findings

Models show late-time phantom acceleration without phantom fluids.

Cosmological evolution interpolates between matter-like and de Sitter-like phases.

No future singularity occurs in these models.

Abstract

A new class of braneworld models displaying late-time phantom acceleration without resorting to a phantom fluid is presented. In this scenario expansion is fuelled by dark matter together with some effective dark energy capable of crossing the phantom divide. Unlike a previous proposal of this nature, in these models the effective phantom behaviour remains valid at all redshifts for some choices of the free parameters of the models. The construction is based on the generalised Chaplygin gas, and the cosmological history interpolates between a standard CDM-like behaviour at early times and a de Sitter-like behaviour at late times, so no future singularity is reached.