Browsing by Author "Juma, Mahamudu"

Now showing 1 - 3 of 3
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    Generalized quark star models with logarithmic pressure anisotropy
    (The University of Dodoma, 2020) Juma, Mahamudu
    The new exact solutions for the charged anisotropic stellar object were found by using Einstein-Maxwell field equations. In this study, the metric function, linear equation of state, and a new choice of the measure of anisotropy were used to formulate new quark star models. The field equations were transformed by adopting Bannerji and Durgapal transformation variables. The general differential equation governing the model was generated with the help of Einstein field equations, and the form of logarithmic measure of anisotropy. The exact solution for the models was obtained by specifying different values of the parameters used in the models. In this model, anisotropic and isotropic results were regained as a special case. We regained anisotropic models found by Maharaj, and isotropic models performed by Misner and Zapolsky, Harko and Mak, Maharaj and Komathiraj. The plotted graphs and physical analysis revealed that matter variables and the gravitational potentials were behaved well. Therefore the models satisfied the energy conditions, stability condition, and speed of sound that were consistent for quark stars.
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    Physical quark star model with generalized logarithmic anisotropy
    (World Scientific Pub Co Pte Ltd, 2023) Mkenyeleye, Jason M.; Juma, Mahamudu; Sunzu, Jefta M.
    A new quark star model for a charged anisotropic stellar object is generated using the Einstein–Maxwell field equations. We use a metric function, linear equation of state, and a new measure of anisotropy in form of logarithmic function to formulate the model. For particular choices of parameters in the anisotropic measure, some anisotropic and isotropic models are regained as a special case. Physical analysis indicates that matter variables and gravitational potentials in the model are well behaved. The generated model satisfies the energy, regularity, causality, and stability conditions. The speed of sound is consistent with quark stars.
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    Quark star models with logarithmic anisotropy
    (Springer, 2022) Juma, Mahamudu; Mkenyeleye, Jason M.; Sunzu, Jefta M.
    New models for the charged anisotropic stellar object were generated using the Einstein–Maxwell field equations. A new choice of pressure anisotropy in logarithmic form was used to generate a quark star model. Anisotropic and isotropic models were regained as a special case. We regained anisotropic models found by Maharaj, Sunzu and Ray; Abdalla, Sunzu and Mkenyeleye; and Sunzu and Danford. The isotropic models regained include the performance by Mak and Harko, and Maharaj and Komathiraj. Physical analysis showed that matter variables and the gravitational potentials are well behaved. Our model does satisfy the energy conditions and stability condition.