Dynamical-Screening and the Phantom-Like Effects in a DGP-Inspired $F(R,\phi)$ Model

TL;DR

This paper explores a DGP-inspired $F(R,)$ model where modifications to induced gravity and scalar field coupling enable phantom-like effects and better fit with observations than other theories.

Contribution

It extends the DGP scenario to a general $F(R,)$ framework, analyzing how gravity modification and scalar coupling influence cosmological screening and phantom behavior.

Findings

Phantom-like behavior achieved without null energy condition violation.

Model fits observational data better than other alternatives.

Modification of induced gravity impacts brane cosmological constant screening.

Abstract

Based on the Lue-Starkman conjecture on the dynamical screening of the brane cosmological constant in the DGP scenario, we extend this proposal to a general DGP-inspired $F(R,\phi)$ Model. We show that modification of the induced gravity and its coupling to a quintessence field localized on the brane, affects the screening of the brane cosmological constant and also phantom-like behavior on the brane. We extend our study to possible modification of the induced gravity on the brane and for clarification some specific examples are presented. As a result, phantom-like behavior can be realized in this setup without violating the null energy condition at least in some subspaces of the model parameter space. The key result of our study is the fact that a DGP-inspired $F(R,\phi)$ scenario has the best fit with LCDM and recent observations than other alternative theories.