Anisotropic extensions of isotropic Finch–Skea metric in the charged modified gravity

The focus of this work is centered on determining whether traversable wormholes admitting Einasto density profile exist within the framework of f(R, T) gravity. Using the Morris–Thorne spacetime, we express the wormhole configuration and formulate the anisotropic gravitational equations for a particular linear modified model. Afterwards, by considering two different (constant and variable) redshift functions, we derive the shape function for wormholes and examine its potential stability. The developed functions conform to the necessary conditions and form a connection between two spacetime regions that are asymptotically flat. We also examine the viability of resulting wormhole solutions by verifying their violation with the null energy conditions. We also investigate the active gravitational mass and the complexity factor for our solutions. The later quantity is found to be negative near the wormhole throat and becomes zero when moving away from this point. Further, various methods of stability analysis are utilized to assess the developed models. Our results suggest that the constructed wormhole geometries meet the necessary conditions, thereby existing within the considered modified gravity.

Imprints of the Einasto density profile and complexity factor on traversable wormholes in f(R, T) theory

Naseer,

Sharif,

Faiza

et al. 2024

Anisotropic extension of the Kohler–Chao–Tikekar cosmological solution with like Wyman IIa complexity factor

Siza,

Andrade,

Santana

et al. 2024

We construct a new stellar compact object model in the regime of anisotropic pressure using the framework of gravitational decoupling via minimal geometric deformation, with the particularity that the seed solution used is the known Kohler–Chao–Tikekar cosmological solution. As an extra condition to close the Einstein’s field equations resulting for this construction, we use a generalised complexity factor for self-gravitating spheres to the well-known Wyman IIa solution. The resulting model fulfils the fundamental physical acceptability stellar conditions for a compactness factor of a pulsar SMC X-1. The stability of the model is also investigated.

Complexity and isotropization based extended models in the context of electromagnetic field: an implication of minimal gravitational decoupling

Naseer

2024

This paper formulates three different analytical solutions to the gravitational field equations in the framework of Rastall theory by taking into account the gravitational decoupling approach. For this, the anisotropic spherical interior fluid distribution is assumed as a seed source characterized by the corresponding Lagrangian. The field equations are then modified by introducing an additional source which is gravitationally coupled with the former fluid setup. Since this approach makes the Rastall equations more complex, the MGD scheme is used to tackle this, dividing these equations into two systems. Some particular ansatz are taken into account to solve the first system, describing initial anisotropic fluid. These metric potentials contain multiple constants which are determined with the help of boundary conditions. On the other hand, the solution for the second set is calculated through different well-known constraints. Afterwards, the estimated data of a pulsar 4U 1820-30 is considered so that the feasibility of the developed models can be checked graphically. It is concluded that all resulting models show physically acceptable behavior under certain choices of Rastall and decoupling parameters.