Narrow Results

This paper is devoted to study static spherically symmetric model in the presence of charged perfect fluid. This is the generalization of neutral perfect fluid (when there is no charge) through the solution of Einstein Maxwell equations. For this purpose, we consider a suitable form of gravitational potential $g_{tt}$ and the electric field $E(r)$, already used in the literature. The value of mass-radius ratio or compactness $u=\frac{M}{R}$, which depends upon the chosen model exceeds the value $\frac{4}{9}$ corresponding to neutral stars. The most important feature of the current study is to use the Bardeen model geometry instead of usual Reissner–Nordström model for the matching conditions. In this case the energy density and pressure remain positive, bounded and monotonically decreasing whereas electric field is monotonically increasing. Also the causality condition, i.e. the magnitude of speed of sound must be less than the speed of light, is satisfied. Moreover, the behavior of all the physical parameters at the center and on surface of star of mass $M\sim M_{\odot }$ and for Her X-1 are tabulated. All the results by graphical analysis and tabular information suggest that Bardeen model provides physically realistic stellar structures.

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 $M=2.01M_{\odot }$, and $R_{𝜖}=9.1$ 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 $n\in [12,15]$, where parameter $n$ is involved in the model under discussion. Beyond this bound $12\le n\le 15$, 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 $\sqrt{R_{𝜖}}/3+\sqrt{R_{𝜖}/9+q^2/3R_{𝜖}}\ge \sqrt{M}$, critically important for the stellar structures, has been achieved in both the models under investigation. Lastly, it is established that the parameter $n$ has a substantial effect on worked-out solutions under the employment of Bardeen and Reissner–Nordstrom’s stellar structures.

This study is explored to discuss the anisotropic nature of charged strange compact stars by considering the MIT bag model in the context of our universe’s accelerated expansion scenario. For this purpose, we choose two models for spherically symmetric space–time components. In Model-I, we plug the embedded space–time to evaluate the Bardeen strange stellar structures. In Model-II, we choose the Krori–Barua space–time. We correlate the Bardeen geometry as an exterior solution with a spherically symmetric interior geometry to acquire unknown parameters involved in the study. We discuss the necessary properties of the strange stellar models with embedded space–time and Krori–Barua space–time via the MIT bag model. After witnessing the minor differences in our proposed models, Andreasson’s limit $\sqrt{M}\le \sqrt{R_{𝜖}}/3+\sqrt{R_{𝜖}/9+q^2/3R_{𝜖}}$ has been fulfilled as required by the charged stellar structures. Further, we conclude that all the acquired results show the stable and self-consistent behavior of charged anisotropic compact structures.

This study enlightens the effect of electric charge in the context of Logarithmic-corrected $R^2$ gravity model by assuming the specific form of metric potentials $\nu (r)=B{r}^2+2ln(C)$ and $\lambda (r)=ln(1+a{r}^2+b{r}^4)$, known as Tolman–Kuchowicz spacetime. The key feature of our study is to assume the Bardeen model to narrate the nature of exterior geometry. This discussion enhances the analysis as the Bardeen black hole solution can be formulated as a gravitationally collapsed magnetic monopole which arises from some particular case of nonlinear electrodynamics. Further, the modified matching conditions, designed for $f(R)$ gravity, have been imposed to compute all the unknown constants involved in metric potentials for the qualitative evaluation of the study. For this purpose, we have studied all the mandatory characteristics of stellar structures like energy density, pressure components, energy bonds, equilibrium condition, stability constraints, mass–radius relation. A comprehensive graphical analysis to ensure the credibility of the $f(R)$ gravity model has been presented. It is worth indicating that our obtained charged anisotropic outcomes are physically well-fitted with the best degree of accuracy.