Late-Time Viscous Cosmology in $f(R,T)$ Gravity

Abstract

The article communicates an alternative route to suffice the late-time acceleration considering a bulk viscous fluid with viscosity coefficient $\zeta ={\zeta }_0+{\zeta }_{1}H+{\zeta }_2{H}^2$, where ${\zeta }_0,{\zeta }_1,{\zeta }_2$ are constants in the framework of $f(R,T)$ modified gravity. We presume the $f(R,T)$ functional form to be $f=R+2\alpha T$ where $\alpha$ is a constant. We then solve the field equations for the Hubble Parameter and study the cosmological dynamics of kinematic variables such as deceleration, jerk, snap and lerk parameters as a function of cosmic time. We observe the deceleration parameter to be highly sensitive to $\alpha$ and undergoes a signature flipping at around $t\sim 10$ Gyrs for $\alpha =-0.179$ which is favored by observations. The EoS parameter for our model assumes values close to $-1$ at $t_0=13.7$Gyrs which is in remarkable agreement with the latest Planck measurements. Next, we study the evolution of energy conditions and find that our model violate the Strong Energy Condition in order to explain the late-time cosmic acceleration. To understand the nature of dark energy mimicked by the bulk viscous baryonic fluid, we perform some geometrical diagnostics like the $\{r,s\}$ and $\{r,q\}$ plane. We found the model to mimic the nature of a Chaplygin gas type dark energy model at early times while a Quintessence type in distant future. Finally, we study the violation of continuity equation for our model and show that in order to explain the cosmic acceleration at the present epoch, energy-momentum must violate.

New Astronomy accepted version

References in corpus (18)

• f(R,T) gravity
• Viscous Cosmology for Early- and Late-Time Universe
• Modelling wormholes in $f(R,T)$ gravity
• Entropic Accelerating Universe
• The simplest non-minimal matter-geometry coupling in the $f(R,T)$ cosmology
• Dark Matter From f(R,T) Gravity
• Does Bulk Viscosity Create a Viable Unified Dark Matter Model?
• Friedmann model with viscous cosmology in modified $f(R,T)$ gravity theory
• Non-exotic matter wormholes in a trace of the energy-momentum tensor squared gravity
• Wormholes in $R^2$-gravity within the $f(R,T)$ formalism
• Dissipation of dark matter
• Non-adiabatic dark fluid cosmology
• Propagation of Polar Gravitational Waves in f(R,T) Scenario
• Viscous dark energy and generalized second law of thermodynamics
• Big Bang Nucleosynthesis and Entropy Evolution in $f(R,T)$ Gravity
• Does information entropy play a role in the expansion and acceleration of the Universe?
• Temporally Varying Universal Gravitational "Constant" and Speed of Light in Energy Momentum Squared Gravity
• Configuration entropy of the Cosmic Web: Can voids mimic the dark energy?

Cited by in corpus (2)

• Evaluation of cosmological models in $f(R,T)$ gravity in different dark energy scenario
• Swampland dS conjecture in Mimetic $f(R,T)$ gravity