Crossing the Phantom Divide in Extended Dvali-Gabadadze-Porrati Gravity

TL;DR

This paper introduces an extended DGP gravity model that allows the effective equation of state to cross the phantom divide, explaining late-time cosmic acceleration without dark energy.

Contribution

The authors develop a modified DGP model that achieves phantom crossing, which was not possible in previous DGP models, providing a new approach to late-time acceleration.

Findings

The model successfully demonstrates crossing of the phantom divide.

Smaller parameter $eta$ leads to earlier crossing epochs.

The model explains late-time acceleration without dark energy.

Abstract

We propose a phantom crossing Dvali--Gabadadze--Porrati (DGP) model. In our model, the effective equation of state of the DGP gravity crosses the phantom divide line. We demonstrate crossing of the phantom divide does not occur within the framework of the original DGP model or the DGP model developed by Dvali and Turner. By extending their model, we construct a model that realizes crossing of the phantom divide. We find that the smaller the value of the new introduced parameter $\beta$ is, the older epoch crossing of the phantom divide occurs in. Our model can account for late-time acceleration of the universe without dark energy. We investigate and show the property of Phantom crossing DGP model.