Attractors, Statefinders and Observational Measurement for Chameleonic Brans--Dicke Cosmology

TL;DR

This paper explores a chameleonic Brans-Dicke cosmological model, analyzing its stability, attractor solutions, and observational signatures, revealing phantom-like behavior without exotic fields and comparing predictions with current data.

Contribution

It develops a phase space framework for stability analysis and introduces statefinder diagnostics for the chameleonic Brans-Dicke model, highlighting its ability to mimic phantom behavior.

Findings

Phantom-like behavior achieved without phantom fields.

Stability and attractor solutions identified in phase space.

Model consistent with current cosmological observations.

Abstract

We investigate chameleonic Brans--Dicke model applied to the FRW universes. A framework to study stability and attractor solutions in the phase space is developed for the model. We show that depending on the matter field and stability conditions, it is possible to realize phantom-like behavior without introducing phantom filed in the model while the stability is fulfilled and phantom crossing occurs. The statefinder parameters to the model for different kinds of matter interacting with the chameleon scalar field are studied. We also compare our model with present day observations.