Cosmological dynamics of a non-minimally coupled bulk scalar field in DGP setup

TL;DR

This paper explores how a non-minimally coupled bulk scalar field influences the cosmological dynamics in a DGP brane-world model, potentially explaining late-time cosmic acceleration without ghosts.

Contribution

It introduces a non-minimally coupled bulk scalar field into the DGP model and analyzes its effects on cosmological evolution and late-time acceleration.

Findings

Non-minimal coupling significantly alters jump conditions.

Normal branch can exhibit phantom-like behavior.

Model can explain late-time acceleration without ghosts.

Abstract

We consider cosmological dynamics of a canonical bulk scalar field, which is coupled non-minimally to 5-dimensional Ricci scalar in a DGP setup. We show that presence of this non-minimally coupled bulk scalar field affects the jump conditions of the original DGP model significantly. Within a superpotential approach, we perform some numerical analysis of the model parameter space and consider bulk-brane energy exchange in this setup. Also we show that the normal, ghost-free branch of the DGP solutions in this case has the potential to realize a self-consistent phantom-like behavior and therefore explains late time acceleration of the universe in a consistent way.