A generalized family of anisotropic compact object in general relativity

TL;DR

This paper develops a generalized model for anisotropic compact stars within Einstein's general relativity, providing solutions that match observed data and analyzing their physical viability through various stability and astrophysical criteria.

Contribution

It introduces a new class of solutions for anisotropic compact stars using a 5D embedding approach, with specific models for known stars and detailed physical analysis.

Findings

Model solutions match observed star parameters.

Stars satisfy energy and stability conditions.

Numerical results align with observational data.

Abstract

We present model for anisotropic compact star under the general theory of relativity of Einstein. In the study a 4-dimensional spacetime has been considered which is embedded into the 5-dimensional flat metric so that the spherically symmetric metric has class 1 when the condition $e^{\lambda}=\left(\,1+C\,e^{\nu} \,{\nu'}^2\,\right)$ is satisfied ($\lambda$ and $\nu$ being the metric potentials along with a constant $C$). A set of solutions for the field equations are found depending on the index $n$ involved in the physical parameters. The interior solutions have been matched smoothly at the boundary of the spherical distribution to the exterior Schwarzschild solution which necessarily provides values of the unknown constants. We have chosen the values of $n$ as $n=2$ and $n$=10 to 20000 for which interesting and physically viable results can be found out. The numerical values of the parameters and arbitrary constants for different compact stars are assumed in the graphical plots and tables as follows: (i) LMC X-4 : $a=0.0075$, $b=0.000821$ for $n=2$ and $a=0.0075$, $nb=0.00164$ for $n\ge 10$, (ii) SMC X-1: $a=0.00681$, $b=0.00078$ for $n=2$, and $a=0.00681$, $nb=0.00159$ for $n \ge 10$. The investigations on the physical features of the model include several astrophysical issues, like (i) regularity behavior of stars at the centre, (ii) well behaved condition for velocity of sound, (iii) energy conditions, (iv) stabilty of the system via the following three techniques - adiabatic index, Herrera cracking concept and TOV equation, (v) total mass, effective mass and compactification factor and (vi) surface redshift. Specific numerical values of the compact star candidates LMC X-4 and SMC X-1 are calculated for central and surface densities as well as central pressure to compare the model value with actual observational data.