arXiv subjects

Saeeda Zia

Publications and source records attributed to Saeeda Zia.

3 recordsLinked to original sources

arXiv2018

Existence of Static Wormhole Solutions in $f(R,G)$ Gravity

This work investigates some feasible regions for the existence of traversable wormhole geometries in $f(R,G)$ gravity, where $R$ and $G$ represent the Ricci scalar and the Gauss-Bonnet invariant respectively. Three different matter contents anisotropic fluid, isotropic fluid and barotropic fluid have been considered for the analysis. Moreover, we split $f(R,G)$ gravity model into Strobinsky like $f(R)$ model and a power law $f(G)$ model to explore wormhole geometries. We select red-shift and shape functions which are suitable for the existence of wormhole solutions for the chosen $f(R,G)$ gravity model. It has been analyzed with the graphical evolution that the null energy and weak energy conditions for the effective energy-momentum tensor are usually violated for the ordinary matter content. However, some small feasible regions for the existence of wormhole solutions have been found where the energy conditions are not violated. The overall analysis confirms the existence of the wormhole geometries in $f(R,G)$ gravity under some reasonable circumstances.

physics.gen-ph↗

arXiv2018

Analysis of Charged Compact Stars in Modified Gravity

Current study highlights the physical characteristics of charged anisotropic compact stars by exploring some exact solutions of modified field equations in $f(R,G)$ gravity. A comprehensive analysis is performed from the obtained solutions regarding stability, energy conditions, regularity, sound velocity and compactness. These solutions can be referred to model the compact celestial entities. In particular, a compact star named, $Her X-1$ has been modeled which indicates that current solution fits and is in conformity to the observational data as well. A useful and interesting fact from this model arises that relative difference between two forces of anisotropic pressure and electromagnetic force may occur inside the aforementioned compact star. This is another mechanism which is essential for stability of the compact object and prevent stellar object to annihilate.

gr-qc↗

arXiv2017

Physical Attributes of Anisotropic Compact Stars in $f(R,G)$ Gravity

Modified gravity is one of the potential candidates to explain the accelerated expansion of the universe. Current study highlights the materialization of anisotropic compact stars in the context of $f(R,G)$ theory of gravity. In particular, to gain insight in the physical behavior of three stars namely, Her $X1$, SAX J $1808$-$3658$ and 4U $1820$-$30$, energy density, and radial and tangential pressures are calculated. The $f(R,G)$ gravity model is split into a Starobinsky like $f(R)$ model and a power law $f(G)$ model. The main feature of the work is a $3$-dimensional graphical analysis in which, anisotropic measurements, energy conditions and stability attributes of these stars are discussed. It is shown that all three stars behave as usual for positive values of $f(G)$ model parameter $n$.

physics.gen-ph↗