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.

Traversable phantom wormholes via conformal symmetry in f(R,φ,χ) gravity

This analysis explores the solutions for wormhole in [Formula: see text] gravity, where [Formula: see text], and [Formula: see text] represent the kinetic term, scalar potential, and Ricci scalar, respectively. For this study, we use the spherically symmetric spacetime with the anisotropic source of matter. Further, we use the linear equation of state to complete this current investigation in the background of conformal symmetry motion. By plugging non-zero conformal Killing vectors, we discuss the feasible phantom wormhole configurations. Under the linear equation of state, the stability of wormhole solutions with specific values of parameters is also checked by using the Tolman–Oppenheimer–Volkoff equation. Further, the energy conditions are also discussed with conformal motions. Moreover, it is concluded that our inquired solutions are physically viable in [Formula: see text] gravity.

Gravitationally decoupled non-static anisotropic spherical solutions

This paper is devoted for the formulation of new anisotropic solutions for non-static spherically symmetric self-gravitating systems through gravitational decoupling technique. Initially, we add a gravitational source in the perfect matter distribution for inducing the effects of anisotropy in the considered model. We then decouple the field equations through minimal geometric deformation approach and derive three new anisotropic solutions. Among these, two anisotropic solutions are evaluated by applying specific constraints on anisotropic source and the third solution is obtained by employing the barotropic equation of state. The physical acceptability and stability of the anisotropic models are investigated through energy conditions and causality condition, respectively. We conclude that all the derived anisotropic solutions are physically viable as well as stable.

Decoupled Embedding Class-One Strange Stars in Self-Interacting Brans–Dicke Gravity

This work aims to extend two isotropic solutions to the anisotropic domain by decoupling the field equations in self-interacting Brans–Dicke theory. The extended solutions are obtained by incorporating an additional source in the isotropic fluid distribution. We deform the radial metric potential to disintegrate the system of field equations into two sets such that each set corresponds to only one source (either isotropic or additional). The system related to the anisotropic source is solved by employing the MIT bag model as an equation of state. Further, we develop two isotropic solutions by plugging well-behaved radial metric potentials in Karmarkar’s embedding condition. The junction conditions at the surface of the star are imposed to specify the unknown constants appearing in the solution. We examine different physical characteristics of the constructed quark star models by using the mass and radius of PSR J1903+327. It is concluded that, in the presence of a massive scalar field, both stellar structures are well-behaved, viable and stable for smaller values of the decoupling parameter.

Anisotropic source modelling for turbulent jet noise prediction

An anisotropic component of the jet noise source model for the Reynolds-averaged Navier–Stokes equation-based jet noise prediction method is proposed. The modelling is based on Goldstein's generalized acoustic analogy, and both the fine-scale and large-scale turbulent noise sources are considered. To model the anisotropic characteristics of jet noise source, the Reynolds stress tensor is used in place of the turbulent kinetic energy. The Launder–Reece–Rodi model (LRR), combined with Menter's ω -equation for the length scale, with modified coefficients developed by the present authors, is used to calculate the mean flow velocities and Reynolds stresses accurately. Comparison between predicted results and acoustic data has been carried out to verify the accuracy of the new anisotropic source model. This article is part of the theme issue ‘Frontiers of aeroacoustics research: theory, computation and experiment’.

Strange stars with MIT bag model in the Rastall theory of gravity

The aim of this paper is to study the charged anisotropic strange stars in the Rastall framework. Basic formulation of field equations in this framework is presented in the presence of charged anisotropic source. To obtain the solutions of the Rastall field equations in spherically symmetric Karori and Barua (KB) type space-time, we have considered a linear equation of state of strange matter, using the MIT bag model. The constraints on the Rastall dimensionless parameter [Formula: see text] are also discussed to obtain the physically reasonable solution. We explore some physical features of the presented model like energy conditions, stability and hydrostatic equilibrium, which are necessary to check the physical viability of the model. We also sought for the influence of the Rastall dimensionless parameter on the behavior of the physical features of obtained solution. We plot the graphs of matter variables for different chosen values of the parameter [Formula: see text] to inspect more details of analytical investigations and predict the numerical values of these variables exhibited in the tabular form. For this analysis, we choose four different arbitrary models of strange stars with compactness [Formula: see text] 0.25, 0.30, 0.35 and 0.40. We observed that all the necessary physical conditions are satisfied and the presented model is quite reasonable to study the strange stars.

Collapse and expansion of plane symmetric charged anisotropic source

In this paper, we have investigated the final evolutionary stages of charged non-static plane symmetric anisotropic source. To this end, we have solved the Einstein–Maxwell field equations with the charged plane symmetric source. We have found that vanishing of radial heat flux in the gravitating source provides the parametric form of the metric functions. The new form of the metric functions can generate a class of physically acceptable solutions depending on the choice parameter. These solutions may be classified as expanding or collapsing solutions with the particular values of generating parameter. The gravitational collapse in this case ends with the formation of single apparent horizon while there exists two such horizons in the case of charged spherical anisotropic source.