arXiv subjects

R. V. Mapari

Publications and source records attributed to R. V. Mapari.

3 recordsLinked to original sources

arXiv2024

Interacting Field Cosmological Model in Lyra Geometry

The paper explores a plane symmetric cosmological model within the framework of the Lyra manifold, incorporating interactions among various fields. These fields include a charged perfect fluid, a mass-less scalar field, and an electromagnetic field. The study focuses on deriving relativistic field equations and exact solutions for this complex system. The relationships between the scalar field (\b{eta}) and the average scale factor (a(t)), as well as between the metric potentials, are assumed to solve the nonlinear field equations. Two specific expansion models are examined: 1) Exponential expansion and 2) Power law expansion. The research delves into the dynamic parameters behavior, observing changes in pressure, density, and cosmological parameters across different models. The findings indicate that while the Universe is expanding, the rate of expansion can vary among the different models. The investigation also involves kinematic parameters, such as jerk and snap parameters derived from the scale factor variation, and compares them to the ΛCDM model.

gr-qc↗

arXiv2024

Energy Conditions in f(R, T) Gravity with an Anisotropic Background

In our study, we explored the properties of a spatially homogeneous and anisotropic Bianchi type V I0 Universe. Our investigation centered on integrating cosmic domain walls into the f(R, T) theory of gravitation, initially proposed by Harko et al. in 2011. To tackle the field equations, we employed the relationship between the expansion scalar (θ) and the shear scalar (σ). Our analysis encompassed both the dynamic and cosmological aspects of the Universe. By comparing our findings to the ΛCDM model, specifically focusing on the evolution of the jerk parameter, we found a striking agreement between the two models. A noteworthy discovery was the verification of accelerated expansion in our described model, consistent with the prevailing observational data. Finally, we examine the energy condition criteria and determine that the violation of the Strong Energy Condition (SEC), while the Null Energy Condition (NEC), Weak Energy Condition (WEC) and Dominant Energy Condition (DEC) continue to meet the requirements for positivity.

gr-qc↗

arXiv2023

Holographic inflation in non-static plane symmetric space-time

The current analysis uses the non-static plane symmetric space-time to dynamically examine the holographic dark energy model as a candidates of IR cut-offs (specifically Hubble's and Granda-Oliveros cut-off). Using the Markov Chain Monte Carlo (MCMC) method, we estimate the best fit values for the model parameters imposed from the combined datasets of $CC+SC+BAO$. Now, it has been found that the characteristics of space-time that have been addressed and formulated using both models are flat universe and observed that the model appears to be in good agreement with the observations. In addition, we investigate the behavior of equation of state parameters along with the energy conditions. Finally, we found that in both the cut-offs the models predict that the present and late universe are accelerating and the equation of state parameter behaves like the quintessence model.

gr-qc↗