Effective equation of state in modified gravity and observational constraints

Abstract

In this article, the bulk viscosity is introduced in a modified gravity model. The gravitational action has a general $f(R,T)$ form, where $R$ and $T$ are the curvature scalar and the trace of energy momentum tensor respectively. An effective equation of state (EoS) has been investigated in the cosmological evolution with bulk viscosity. In the present scenario, the Hubble parameter which has a scaling relation with the redshift can be obtained generically. The role of deceleration parameter $q$ and equation of state parameter $\omega$ is discussed to explain the late-time accelerating expansion of the universe. The statefinder parameters and Om diagnostic analysis are discussed for our obtained model to distinguish from other dark energy models together with the analysis of energy conditions and velocity of sound for the model. We have also numerically investigated the model by detailed maximum likelihood analysis of $580$ Type Ia supernovae from Union $2.1$ compilation datasets and updated $57$ Hubble datasets ($31$ data points from differential age method and $26$ points from BAO and other methods). It is with efforts found that the present model is in good agreement with observations.

CQG accepted version

References in corpus (21)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• Unified cosmic history in modified gravity: from F(R) theory to Lorentz non-invariant models
• f(R,T) gravity
• Raising the bar: new constraints on the Hubble parameter with cosmic chronometers at z$\sim$2
• Baryon Acoustic Oscillations in the Lyα forest of BOSS DR11 quasars
• Two new diagnostics of dark energy
• Baryon Acoustic Oscillations in the Ly-α forest of BOSS quasars
• Inflationary cosmology in modified gravity theories
• Viscous Cosmology for Early- and Late-Time Universe
• FRW Cosmology in F(R,T) gravity
• The simplest non-minimal matter-geometry coupling in the $f(R,T)$ cosmology
• Kinematic Constraints to the Transition Redshift from SNe Ia Union Data
• Friedmann model with viscous cosmology in modified $f(R,T)$ gravity theory
• A litmus test for Lambda
• Dark energy with non-adiabatic sound speed: initial conditions and detectability
• $Om$ diagnostic applied to scalar field models and slowing down of cosmic acceleration
• When did cosmic acceleration start? How fast was the transition?
• Testing the equation of state for viscous dark energy
• Finite-time future singularities models in $f(T)$ gravity and the effects of viscosity
• Viscosity in modified gravity
• Viscous Dark Energy in $f(T)$ Gravity

Cited by in corpus (3)

• Cosmography in $f(Q)$ gravity
• Power-law cosmology in Weyl-type $f(Q,T)$ gravity
• Viscous cosmology in $f(T)$ gravity