Effective equation of state in modified gravity and observational constraints. (29th September 2020)

• Record Type: Journal Article
• Authors: Arora, Simran; Meng, Xin-he; Pacif, S K J; Sahoo, P K
• Is Part Of: Classical and quantum gravity. Volume 37:Number 20(2020:Oct.)
• Publication Date: 2020-09-29
• Subjects: f(R, T) gravity -- equation of state -- bulk viscosity -- energy conditions -- observational constraints; Quantum gravity -- Periodicals; Gravitation -- Periodicals; Relativity (Physics) -- Periodicals; Space and time -- Periodicals; Periodicals; 521.1
• DOI: 10.1088/1361-6382/aba587
• Languages: English
• ISSNs: 0264-9381

Abstract

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 EoS parameter ω 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.