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Analysis of the fractional relativistic polytropic gas sphere

Many stellar configurations, including white dwarfs, neutron stars, black holes, supermassive stars, and star clusters, rely on relativistic effects. The Tolman–Oppenheimer–Volkoff (TOV) equation of the polytropic gas sphere is ultimately a hydrostatic equilibrium equation developed from the general...

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Autores principales: Aboueisha, Mohamed S., Nouh, Mohamed I., Abdel-Salam, Eamad A. -B., Kamel, Tarek M., Beheary, M. M., Gadallah, Kamel A. K.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10471581/
https://www.ncbi.nlm.nih.gov/pubmed/37652937
http://dx.doi.org/10.1038/s41598-023-41392-y
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author Aboueisha, Mohamed S.
Nouh, Mohamed I.
Abdel-Salam, Eamad A. -B.
Kamel, Tarek M.
Beheary, M. M.
Gadallah, Kamel A. K.
author_facet Aboueisha, Mohamed S.
Nouh, Mohamed I.
Abdel-Salam, Eamad A. -B.
Kamel, Tarek M.
Beheary, M. M.
Gadallah, Kamel A. K.
author_sort Aboueisha, Mohamed S.
collection PubMed
description Many stellar configurations, including white dwarfs, neutron stars, black holes, supermassive stars, and star clusters, rely on relativistic effects. The Tolman–Oppenheimer–Volkoff (TOV) equation of the polytropic gas sphere is ultimately a hydrostatic equilibrium equation developed from the general relativity framework. In the modified Riemann Liouville (mRL) frame, we formulate the fractional TOV (FTOV) equations and introduce an analytical solution. Using power series expansions in solving FTOV equations yields a limited physical range to the convergent power series solution. Therefore, combining the two techniques of Euler–Abel transformation and Padé approximation has been applied to improve the convergence of the obtained series solutions. For all possible values of the relativistic parameters ([Formula: see text] ), we calculated twenty fractional gas models for the polytropic indexes n = 0, 0.5, 1, 1.5, 2. Investigating the impacts of fractional and relativistic parameters on the models revealed fascinating phenomena; the two effects for n = 0.5 are that the sphere’s volume and mass decrease with increasing [Formula: see text] and the fractional parameter ([Formula: see text] ). For n = 1, the volume decreases when [Formula: see text]  = 0.1 and then increases when [Formula: see text]  = 0.2 and 0.3. The volume of the sphere reduces as both [Formula: see text] and [Formula: see text] increase for n = 1.5 and n = 2. We calculated the maximum mass and the corresponding minimum radius of the white dwarfs modeled with polytropic index n = 3 and several fractional and relativistic parameter values. We obtained a mass limit for the white dwarfs somewhat near the Chandrasekhar limit for the integer models with small relativistic parameters ([Formula: see text] , [Formula: see text] ). The situation is altered by lowering the fractional parameter; the mass limit increases to M(limit) = 1.63348 M(⊙) at [Formula: see text] and [Formula: see text] .
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spelling pubmed-104715812023-09-02 Analysis of the fractional relativistic polytropic gas sphere Aboueisha, Mohamed S. Nouh, Mohamed I. Abdel-Salam, Eamad A. -B. Kamel, Tarek M. Beheary, M. M. Gadallah, Kamel A. K. Sci Rep Article Many stellar configurations, including white dwarfs, neutron stars, black holes, supermassive stars, and star clusters, rely on relativistic effects. The Tolman–Oppenheimer–Volkoff (TOV) equation of the polytropic gas sphere is ultimately a hydrostatic equilibrium equation developed from the general relativity framework. In the modified Riemann Liouville (mRL) frame, we formulate the fractional TOV (FTOV) equations and introduce an analytical solution. Using power series expansions in solving FTOV equations yields a limited physical range to the convergent power series solution. Therefore, combining the two techniques of Euler–Abel transformation and Padé approximation has been applied to improve the convergence of the obtained series solutions. For all possible values of the relativistic parameters ([Formula: see text] ), we calculated twenty fractional gas models for the polytropic indexes n = 0, 0.5, 1, 1.5, 2. Investigating the impacts of fractional and relativistic parameters on the models revealed fascinating phenomena; the two effects for n = 0.5 are that the sphere’s volume and mass decrease with increasing [Formula: see text] and the fractional parameter ([Formula: see text] ). For n = 1, the volume decreases when [Formula: see text]  = 0.1 and then increases when [Formula: see text]  = 0.2 and 0.3. The volume of the sphere reduces as both [Formula: see text] and [Formula: see text] increase for n = 1.5 and n = 2. We calculated the maximum mass and the corresponding minimum radius of the white dwarfs modeled with polytropic index n = 3 and several fractional and relativistic parameter values. We obtained a mass limit for the white dwarfs somewhat near the Chandrasekhar limit for the integer models with small relativistic parameters ([Formula: see text] , [Formula: see text] ). The situation is altered by lowering the fractional parameter; the mass limit increases to M(limit) = 1.63348 M(⊙) at [Formula: see text] and [Formula: see text] . Nature Publishing Group UK 2023-08-31 /pmc/articles/PMC10471581/ /pubmed/37652937 http://dx.doi.org/10.1038/s41598-023-41392-y Text en © The Author(s) 2023 https://creativecommons.org/licenses/by/4.0/Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) .
spellingShingle Article
Aboueisha, Mohamed S.
Nouh, Mohamed I.
Abdel-Salam, Eamad A. -B.
Kamel, Tarek M.
Beheary, M. M.
Gadallah, Kamel A. K.
Analysis of the fractional relativistic polytropic gas sphere
title Analysis of the fractional relativistic polytropic gas sphere
title_full Analysis of the fractional relativistic polytropic gas sphere
title_fullStr Analysis of the fractional relativistic polytropic gas sphere
title_full_unstemmed Analysis of the fractional relativistic polytropic gas sphere
title_short Analysis of the fractional relativistic polytropic gas sphere
title_sort analysis of the fractional relativistic polytropic gas sphere
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10471581/
https://www.ncbi.nlm.nih.gov/pubmed/37652937
http://dx.doi.org/10.1038/s41598-023-41392-y
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