Relativistic compact stars in Tolman spacetime via an anisotropic approach

In this present work, we have obtained a singularity-free spherically symmetric stellar model with anisotropic pressure in the background of Einstein's general theory of relativity. The Einstein's field equations have been solved by exploiting Tolman {\em ansatz} [Richard C Tolman, Phys. Rev. 55:364, 1939] in $(3+1)$-dimensional space-time. Using observed values of mass and radius of the compact star PSR J1903+327, we have calculated the numerical values of all the constants from the boundary conditions. All the physical characteristics of the proposed model have been discussed both analytically and graphically. The new exact solution satisfies all the physical criteria for a realistic compact star. The matter variables are regular and well behaved throughout the stellar structure. Constraints on model parameters have been obtained. All the energy conditions are verified with the help of graphical representation. The stability condition of the present model has been described through different testings.Comment: 18 Pages, 8 Figures, Accepted in European Physical Journal C on 12.06.202

Model of compact star with ordinary and darkmatter

We study compact stars formed by dark and ordinary matter, with attributes of both neutron star matter and quark star matter. We assume an equation of state for dark matter which is consistent with the rotational curves of galaxies and for color-flavor-locked (CFL) distributions for ordinary matter. This is done in the curved Krori-Barua spacetime geometry in general relativity. We find new exact solutions of dark matter admixed compact objects, with maximum mass 2.67 M and radius around 11.16 km, with 52.40% of dark matter content. By varying the dark matter ratio, we obtain the masses of dark compact stars with masses less than 2.67 M

Effect of electric charge on conformal compact stars

Abstract We investigate the effect of electric charge in anisotropic compact stars with conformal symmetry. We assume that the pressure and the density of the matter inside the stellar structure are large with strong gravitational fields. The strong electric field produces significant effects on the phenomenology of the stellar objects, in order of $$10^{20}~\text {V m}^{-1}$$ 1020Vm-1 in MKSA units. The conformal symmetry condition produces an integral relationship between the metric functions. We use this condition to find a new anisotropic solution to the Einstein–Maxwell field equations. This solution is relevant in modelling a relativistic compact star. Radii and masses are consistent with stellar objects such PSR J1614-2230, Vela X1, PSR J1903+327 and Cen X-3. The mass-radius ratio and the surface red shift are in agreement with realistic constraints. Also our model displays constraint on the maximum stellar mass, central density and radius for the upper bound redshift requirements

Spherical conformal models for compact stars

Abstract We consider spherical exact models for compact stars with anisotropic pressures and a conformal symmetry. The conformal symmetry condition generates an integral relationship between the gravitational potentials. We solve this condition to find a new anisotropic solution to the Einstein field equations. We demonstrate that the exact solution produces a relativistic model of a compact star. The model generates stellar radii and masses consistent with PSR J1614-2230, Vela X1, PSR J1903+327 and Cen X-3. A detailed physical examination shows that the model is regular, well behaved and stable. The mass–radius limit and the surface red shift are consistent with observational constraints