Super-acceleration on the Brane by Energy Flow from the Bulk

TL;DR

This paper presents an exact solution for a brane cosmological model with energy exchange from the bulk, showing the universe can naturally enter a super-accelerating phase consistent with observational data.

Contribution

It introduces a solvable brane-world model with energy flow from the bulk, demonstrating a transition in effective dark energy behavior and fitting observational data.

Findings

The universe is in a super-accelerating phase with w_eff < -1.

The model predicts w_de0_eff = -1.21, consistent with super-acceleration.

The equation of state transitions from > -1 to < -1 for effective dark energy.

Abstract

We consider a brane cosmological model with energy exchange between brane and bulk. Parameterizing the energy exchange term by the scale factor and Hubble parameter, we are able to exactly solve the modified Friedmann equation on the brane. In this model, the equation of state for the effective dark energy has a transition behavior changing from $w_{de}^{eff}>-1$ to $w_{de}^{eff}<-1$, while the equation of state for the dark energy on the brane has $w>-1$. Fitting data from type Ia supernova, Sloan Digital Sky Survey and Wilkinson Microwave Anisotropy Probe, our universe is predicted now in the state of super-acceleration with $w_{de0}^{eff}=-1.21$.