Browsing by Author "Maharaj, S. D."

Now showing 1 - 6 of 6
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    Charged anisotropic fluid spheres with conformal symmetry
    (Springer, 2023) Jape, J. W.; Maharaj, S. D.; Sunzu, J. M.; Mkenyeleye, J. M.
    We generate charged anisotropic exact models to the Einstein–Maxwell field equations for static spacetime with a conformal Killing vector. The Einstein–Maxwell field equations are solved to generate a realistic stellar model with physical significance. The generated model satisfies important physical requirements. The interior and exterior metrics match smoothly at the stellar surface, the surface red shift and the compactification parameter are within the suggested limits, regularity is obeyed, the energy conditions are satisfied, the sphere is stable, and the natural physical forces are balanced. The class of exact solutions generated in our model regains several models found by various researchers in the past. These include the models of Buchdahl, Vaidya and Tikekar, Durgapal and Bannerji, amongst other well-known solutions. The existence of a conformal Killing vector provides a geometric basis for many astrophysical objects.
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    Charged anisotropic models for quark stars
    (Springer, 2014) Sunzu, J. M.; Maharaj, S. D.; Ray, S.
    We perform a detailed physical analysis for a class of exact solutions for the Einstein-Maxwell equations. The linear equation of state consistent with quark stars has been incorporated in the model. The physical analysis of the exact solutions is performed by considering the charged anisotropic stars for the particular nonsingular exact model obtained by Maharaj, Sunzu and Ray. In performing such an analysis we regain masses obtained by previous researchers for isotropic and anisotropic matter. It is also indicated that other masses and radii may be generated which are in acceptable ranges consistent with observed values of stellar objects. A study of the mass-radius relation indicates the effect of the electromagnetic field and anisotropy on the mass of the relativistic star
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    Charged conformal stars and equation of state
    (Springer, 2023) Jape, J. W .; Sunzu, J. M.; Maharaj, S. D.; Mkenyeleye, J. M.
    Charged anisotropic fluid spheres admitting a conformal Killing vector with a linear equation of state are generated. Our approach incorporates a conformal symmetry and an equation of state to obtain the electric field intensity. The choice for one of the gravitational potentials from the conformal Killing relation is made on physical grounds to generate realistic stellar models with astrophysical significance. Several solutions generated in the past are contained in our generalized class of exact solution. The exact solutions satisfy several important physical conditions. The matching of the interior and exterior metrics is done smoothly at the stellar boundary. The mass, surface red shift, and compactness factor are compatible with observations. The stability requirement is obeyed, and the physical forces balance for equilibrium. The regularity condition is also satisfied.
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    Generalized compact star models with conformal symmetry
    (Springer, 2021) Maharaj, S. D.; Sunzu, J. M.; Mkenyeleye, J. M.; Jape, J. M.
    We generate a new generalized regular charged anisotropic exact model that admits conformal symmetry in static spherically symmetric spacetime. Our model was examined for physical acceptability as realistic stellar models. The regularity is not violated, the energy conditions are satisfied, the physical forces balanced at equilibrium, the stability is satisfied via adiabatic index, and the surface red shift and mass–radius ratio are within the required bounds. Our conformal charged anisotropic exact solution contains models generated by Finch–Skea, Vaidya–Tikekar and Schwarzschild. Also, some recent charged or neutral and anisotropic or isotropic conformally symmetric models are found as special cases of our exact model. Our approach sing a conformal symmetry provides a generalized geometric framework for studying compact objects.
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    Some simple models for quark stars
    (Springer, 2014) Maharaj, S. D.; Sunzu, J. M.; Ray, S.
    We find two new classes of exact solutions for the Einstein-Maxwell equations. The solutions are obtained by considering charged anisotropic matter with a linear equation of state consistent with quark stars. The field equations are integrated by specifying forms for the measure of anisotropy and a gravitational potential which are physically reasonable. The solutions found generalize the Mark-Harko model and the Komathiraj-Maharaj model. A graphical analysis indicates that the matter variables are well behaved.
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    Stellar models with generalized pressure anisotropy
    (Springer, 2019) Sunzu, J. M.; Mathias, A. K.; Maharaj, S. D.
    New models for a charged anisotropic star in general relativity are found. We consider a linear equation of state consistent with a strange quark star. In our models a new form of measure of anisotropy is formulated; our choice is a generalization of other pressure anisotropies found in the past by other researchers. Our results generalize quark star models obtained from the Einstein–Maxwell equations. Well-known particular charged models are also regained. We indicate that relativistic stellar masses for several stars are obtained using the general mass function found in our model.