Relativistic anisotropic charged fluid spheres with varying cosmological constant

TL;DR

This paper investigates static, spherically symmetric anisotropic charged fluid spheres with a spatially varying cosmological constant, deriving solutions that can be electromagnetic in origin and challenging the necessity of the pure charge condition.

Contribution

It introduces new solutions to Einstein-Maxwell equations with a variable cosmological constant, showing electromagnetic mass models without requiring the pure charge condition.

Findings

Solutions reduce to isotropic cases under certain conditions

Electromagnetic origin of solutions demonstrated

Pure charge condition not always necessary for electromagnetic mass models

Abstract

Static spherically symmetric anisotropic source has been studied for the Einstein-Maxwell field equations assuming the erstwhile cosmological constant $ \Lambda $ to be a space-variable scalar, viz., $ \Lambda = \Lambda(r) $. Two cases have been examined out of which one reduces to isotropic sphere. The solutions thus obtained are shown to be electromagnetic in origin as a particular case. It is also shown that the generally used pure charge condition, viz., $ \rho + p_r = 0 $ is not always required for constructing electromagnetic mass models.