Brane-bulk energy exchange : a model with the present universe as a global attractor

TL;DR

This paper investigates a braneworld model with energy exchange and induced gravity, showing it can naturally lead to an accelerating universe with dark energy properties consistent with observations.

Contribution

It demonstrates the existence of a global attractor in brane-bulk models that accounts for current cosmic acceleration and dark energy behavior.

Findings

The model predicts a dark energy equation of state w_{DE,0} between -1.4 and -1.03.

The universe's evolution includes crossing the w_{DE}=-1 line.

A wide parameter range yields a universe similar to our current observations.

Abstract

The role of brane-bulk energy exchange and of an induced gravity term on a single braneworld of negative tension and vanishing effective cosmological constant is studied. It is shown that for the physically interesting cases of dust and radiation a unique global attractor which can realize our present universe (accelerating and 0<Omega_{m0}<1) exists for a wide range of the parameters of the model. For Omega_{m0}=0.3, independently of the other parameters, the model predicts that the equation of state for the dark energy today is w_{DE,0}=-1.4, while Omega_{m0}=0.03 leads to w_{DE,0}=-1.03. In addition, during its evolution, w_{DE} crosses the w_{DE}=-1 line to smaller values.