arXiv subjects

V. J. Dagwal

Publications and source records attributed to V. J. Dagwal.

5 recordsLinked to original sources

arXiv2023

Two fluid cosmological models in $f(R, T)$ theory of gravity

Present work deals with the two fluid Bianchi Type-V cosmological models consisting of matter and radiating source in the $f(R, T)$ theory of gravity studied by Harko et al. (2011). In this paper, we developed a new idea about $f(R, T)$ gravity with the help of two fluids: one fluid is matter field modeling material content of the Universe and other fluid is radiation field modeling the CMB. We have determined the solution of the two fluid gravitational field equations with the systematic structure in $f(R, T)$ gravity. Here we have deliberated four types of universe such as dust universe, radiation universe, hard universe and Zeldovich universe and also extended our work to observe the big rip and big bang singularity. We have also tested the cosmological parameters.

gr-qc↗

arXiv2023

Cold Dark Matter and Holographic Dark Energy Cosmological Model with Big rip singularity

We have explored cold dark matter and holographic dark energy cosmological models with big rip singularity. To obtain the solution of the field equation, we have supposed that scalar expansion $θ$ is proportional to shear scalar $σ^2 $ which leads to $p_1=(p_2) ^n $, where $A_1 $, $A_2$ are metric potentials and $ n$ is constant. Big bang and Big rip singularity are investigated and analyzed the state-finder parameter. The physical and geometrical parameters of the universe are explained.

gr-qc↗

arXiv2020

Role of the constant deceleration parameter in cosmological models with perfect fluid and dark energy

The main purpose of the present paper is to investigate LRS Bianchi type I metric in the presence of perfect fluid and dark energy. In order to obtain a deterministic solution of the field equations we have assumed that, the two sources of the perfect fluid and dark energy interact minimally with separate conservation of their energy momentum tensors. The EoS parameter of the perfect fluid is also assumed to be constant. In addition to these we have used a special law of variation of Hubble parameter proposed by Berman that yields constant deceleration parameter. For two different values of the constant deceleration parameters we have obtained two different cosmological models. The physical behaviors of both the models have been discussed by using some physical parameters.

gr-qc↗

arXiv2018

Tilted Two Fluids Cosmological Models with Variable G and Λ In General Relativity

Tilted two fluids cosmological models with variable G and Λ In General Relativity are presented. Here one fluid is matter field modelling material content of the universe and another fluid is radiation field modelling the cosmic microwave background (CMB). The tiltedness is also considered .To get the deterministic model, we have assumed a supplementary condition where s and n are constants. We have also discussed the behaviours of some physical parameters.

gr-qc↗

arXiv2016

Tilted and Non Tilted C-Field Cosmological Models

Tilted and non tilted homogeneous plane symmetric C-field cosmological models are investigated. Using the method of Narlikar and Padmanabhan [4], the solutions have been presented when the creation field C is function of time t only. To get the deterministic model, we have assumed the supplementary condition between pressure and density . The behaviour of different stages of the universe has been studied in non tilted models. We have also investigated the behaviours of some physical parameters.

gr-qc↗