Evolution of the density parameter in the anisotropic DGP cosmology

TL;DR

This paper investigates how anisotropy and shear influence the evolution of the density parameter in the DGP braneworld cosmology, revealing significant deviations from standard models and implications for cosmic acceleration.

Contribution

It provides a detailed analysis of the density parameter evolution in anisotropic DGP models, highlighting the effects of shear and cross-over scale, and estimates shear consistent with observational constraints.

Findings

Evolution of $ ho$ parameter is significantly altered by anisotropy.

The universe's transition to acceleration depends on shear, not just density.

Estimated shear parameter aligns with observational limits.

Abstract

Evolution of the density parameter in the anisotropic DGP braneworld model is studied. The role of shear and cross-over scale in the evolution of $\Omega_\rho$ is examined for both the branches of solution in the DGP model. The evolution is modified significantly compared to the FRW model and further it does not depend on the value of $\gamma$ alone. Behaviour of the cosmological density parameter $\Omega_\rho$ is unaltered in the late universe. The study of decceleration parameter shows that the entry of the universe into self accelerating phase is determined by the value of shear. We also obtain an estimate of the shear parameter $\frac{\Sigma}{H_0} \sim 1.68 \times 10^{-10}$, which is in agreement with the constraints obtained in the literature using data.