A comparative analysis of self-consistent charged anisotropic spheres

This study is devoted to exploring the charged stellar structures under embedded space–time using the Karmarkar condition. For this, spherically symmetric space–time with the anisotropic source of fluid possessing an electric charge has been incorporated. Further, the Bardeen and Reissner–Nordstrom geometries have been employed as exterior space–time to calculate the values of the involved constants. The interior solutions of a stellar object have been worked out with the observational mass [Formula: see text], and [Formula: see text] km. It is argued that the acquired solutions accomplish all the necessary conditions for self-consistent charged stars. It has been noted through the detailed graphical analysis that our obtained solutions are physically stable and self-consistent with the best degree of accuracy for [Formula: see text], where parameter [Formula: see text] is involved in the model under discussion. Beyond this bound [Formula: see text], the realistic solutions of stellar models under discussion could not be found. After perceiving the marginal dissimilarities between our proposed models in both cases, Andreasson’s limit [Formula: see text], critically important for the stellar structures, has been achieved in both the models under investigation. Lastly, it is established that the parameter [Formula: see text] has a substantial effect on worked-out solutions under the employment of Bardeen and Reissner–Nordstrom’s stellar structures.

Stability of anisotropic spheres

This work is devoted to understanding the dynamical instability of spherically symmetric space–time in the background of Einstein-Λ gravity. For this purpose, we have considered a spherical geometric distribution and assumed that it is filled with an anisotropic fluid. To proceed with our analysis, we have calculated the corresponding field as well as the mass function. We found nonlinear behavior of physical variables. To deal with that situation, we have subjected our system to the radial perturbations. We assume that after a particular era, our structural quantities have the same time dependence parameter. After linearizing the basic expressions, we have studied the impact of the cosmological constant in the modeling of relativistic stars. It is concluded that Λ tends to slow down the rate of spherical anisotropic collapse.

Upper bounds on the compactness at the innermost light ring of anisotropic horizonless spheres

In the background of isotropic horizonless spheres, Hod recently provided an analytical proof of a bound on the compactness at the innermost light ring with the dominant energy condition. In this work, we extend the discussion of isotropic spheres to anisotropic spheres. With the dominant energy and non-negative trace conditions, we prove that Hod’s bound also holds in the case of anisotropic horizonless spheres.