{"title":"最小耦合重力下带电各向异性奇异星模型","authors":"H. Nazar, G. Abbas","doi":"10.1155/2021/6698208","DOIUrl":null,"url":null,"abstract":"<jats:p>In the present article, we have investigated a new family of nonsingular solutions of static relativistic compact sphere which incorporates the characteristics of anisotropic fluid and electromagnetic field in the context of minimally coupled <jats:inline-formula>\n <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M2\">\n <mi>f</mi>\n <mfenced open=\"(\" close=\")\" separators=\"|\">\n <mrow>\n <mi>R</mi>\n </mrow>\n </mfenced>\n </math>\n </jats:inline-formula> theory of gravity. The strange matter <jats:inline-formula>\n <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M3\">\n <mtext>MIT</mtext>\n </math>\n </jats:inline-formula> bag model equation of state (EoS) has been considered along with the usual forms of the Karori–Barua <jats:inline-formula>\n <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M4\">\n <mfenced open=\"(\" close=\")\" separators=\"|\">\n <mrow>\n <mtext>KB</mtext>\n </mrow>\n </mfenced>\n </math>\n </jats:inline-formula> metric potentials. For this purpose, we derived the Einstein–Maxwell field equations in the assistance of strange matter EoS and <jats:inline-formula>\n <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M5\">\n <mtext>KB</mtext>\n </math>\n </jats:inline-formula> type ansatz by employing the two viable and cosmologically well-consistent models of <jats:inline-formula>\n <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M6\">\n <mi>f</mi>\n <mfenced open=\"(\" close=\")\" separators=\"|\">\n <mrow>\n <mi>R</mi>\n </mrow>\n </mfenced>\n <mo>=</mo>\n <mi>R</mi>\n <mo>+</mo>\n <mi>γ</mi>\n <msup>\n <mrow>\n <mi>R</mi>\n </mrow>\n <mrow>\n <mn>2</mn>\n </mrow>\n </msup>\n </math>\n </jats:inline-formula> and <jats:inline-formula>\n <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M7\">\n <mi>f</mi>\n <mfenced open=\"(\" close=\")\" separators=\"|\">\n <mrow>\n <mi>R</mi>\n </mrow>\n </mfenced>\n <mo>=</mo>\n <mi>R</mi>\n <mo>+</mo>\n <mi>γ</mi>\n <mi>R</mi>\n <mfenced open=\"(\" close=\")\" separators=\"|\">\n <mrow>\n <mi>R</mi>\n <mo>+</mo>\n <mi>α</mi>\n <msup>\n <mrow>\n <mi>R</mi>\n </mrow>\n <mrow>\n <mn>2</mn>\n </mrow>\n </msup>\n </mrow>\n </mfenced>\n </math>\n </jats:inline-formula>. Thereafter, we have checked the physical acceptability of the proposed results such as pressure, energy density, energy conditions, <jats:inline-formula>\n <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M8\">\n <mtext>TOV</mtext>\n </math>\n </jats:inline-formula> equation, stability conditions, mass function, compactness, and surface redshift by using graphical representation. Moreover, we have investigated that the energy density and radial pressure are nonsingular at the core or free from central singularity and always regular at every interior point of the compact sphere. The numerical values of such parameters along with the surface density, charge to radius ratio, and bag constant are computed for three well-known compact stars such as <jats:inline-formula>\n <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M9\">\n <mfenced open=\"(\" close=\")\" separators=\"|\">\n <mrow>\n <mtext>CS1</mtext>\n </mrow>\n </mfenced>\n <mtext>SAXJ</mtext>\n <mn>1808</mn>\n <mtext>.</mtext>\n <mn>4</mn>\n <mo>−</mo>\n <mn>3658</mn>\n </math>\n </jats:inline-formula> (<jats:inline-formula>\n <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M10\">\n <mfenced open=\"(\" close=\")\" separators=\"|\">\n <mrow>\n <mover accent=\"true\">\n <mi>x</mi>\n <mo>˜</mo>\n </mover>\n <mo>=</mo>\n <mn>7.07</mn>\n <mo> </mo>\n <mtext>km</mtext>\n </mrow>\n </mfenced>\n </math>\n </jats:inline-formula>, <jats:inline-formula>\n <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M11\">\n <mfenced open=\"(\" close=\")\" separators=\"|\">\n <mrow>\n <mtext>CS2</mtext>\n </mrow>\n </mfenced>\n <mtext>VelaX</mtext>\n <mo>−</mo>\n <mn>1</mn>\n </math>\n </jats:inline-formula>\n <jats:inline-formula>\n <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M12\">\n <mfenced open=\"(\" close=\")\" separators=\"|\">\n <mrow>\n <mover accent=\"true\">\n <mi>x</mi>\n <mo>˜</mo>\n </mover>\n <mo>=</mo>\n <mn>9.56</mn>\n <mo> </mo>\n <mtext>km</mtext>\n </mrow>\n </mfenced>\n </math>\n </jats:inline-formula>, and <jats:inline-formula>\n <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M13\">\n <mfenced open=\"(\" close=\")\" separators=\"|\">\n <mrow>\n <mtext>CS3</mtext>\n </mrow>\n </mfenced>\n <mtext>4U1820</mtext>\n <mo>−</mo>\n <mn>30</mn>\n </math>\n </jats:inline-formula>\n <jats:inline-formula>\n <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M14\">\n <mfenced open=\"(\" close=\")\" separators=\"|\">\n <mrow>\n <mover accent=\"true\">\n <mi>x</mi>\n <mo>˜</mo>\n </mover>\n <mo>=</mo>\n <mn>10</mn>\n <mo> </mo>\n <mtext>km</mtext>\n </mrow>\n </mfenced>\n </math>\n </jats:inline-formula> and are presented in Tables 1–6. Conclusively, we have noticed that our presented charged compact stellar object in the background of two well-known <jats:inline-formula>\n <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M15\">\n <mi>f</mi>\n <mfenced open=\"(\" close=\")\" separators=\"|\">\n <mrow>\n <mi>R</mi>\n </mrow>\n </mfenced>\n </math>\n </jats:inline-formula> models obeys all the necessary conditions for the stable equilibrium position and which is also perfectly fit to compose the strange quark star object.</jats:p>","PeriodicalId":48962,"journal":{"name":"Advances in Astronomy","volume":" ","pages":""},"PeriodicalIF":1.6000,"publicationDate":"2021-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"3","resultStr":"{\"title\":\"Model of Charged Anisotropic Strange Stars in Minimally Coupled \\n f\\n \\n \\n R\\n \\n \\n Gravity\",\"authors\":\"H. Nazar, G. Abbas\",\"doi\":\"10.1155/2021/6698208\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<jats:p>In the present article, we have investigated a new family of nonsingular solutions of static relativistic compact sphere which incorporates the characteristics of anisotropic fluid and electromagnetic field in the context of minimally coupled <jats:inline-formula>\\n <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\" id=\\\"M2\\\">\\n <mi>f</mi>\\n <mfenced open=\\\"(\\\" close=\\\")\\\" separators=\\\"|\\\">\\n <mrow>\\n <mi>R</mi>\\n </mrow>\\n </mfenced>\\n </math>\\n </jats:inline-formula> theory of gravity. The strange matter <jats:inline-formula>\\n <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\" id=\\\"M3\\\">\\n <mtext>MIT</mtext>\\n </math>\\n </jats:inline-formula> bag model equation of state (EoS) has been considered along with the usual forms of the Karori–Barua <jats:inline-formula>\\n <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\" id=\\\"M4\\\">\\n <mfenced open=\\\"(\\\" close=\\\")\\\" separators=\\\"|\\\">\\n <mrow>\\n <mtext>KB</mtext>\\n </mrow>\\n </mfenced>\\n </math>\\n </jats:inline-formula> metric potentials. For this purpose, we derived the Einstein–Maxwell field equations in the assistance of strange matter EoS and <jats:inline-formula>\\n <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\" id=\\\"M5\\\">\\n <mtext>KB</mtext>\\n </math>\\n </jats:inline-formula> type ansatz by employing the two viable and cosmologically well-consistent models of <jats:inline-formula>\\n <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\" id=\\\"M6\\\">\\n <mi>f</mi>\\n <mfenced open=\\\"(\\\" close=\\\")\\\" separators=\\\"|\\\">\\n <mrow>\\n <mi>R</mi>\\n </mrow>\\n </mfenced>\\n <mo>=</mo>\\n <mi>R</mi>\\n <mo>+</mo>\\n <mi>γ</mi>\\n <msup>\\n <mrow>\\n <mi>R</mi>\\n </mrow>\\n <mrow>\\n <mn>2</mn>\\n </mrow>\\n </msup>\\n </math>\\n </jats:inline-formula> and <jats:inline-formula>\\n <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\" id=\\\"M7\\\">\\n <mi>f</mi>\\n <mfenced open=\\\"(\\\" close=\\\")\\\" separators=\\\"|\\\">\\n <mrow>\\n <mi>R</mi>\\n </mrow>\\n </mfenced>\\n <mo>=</mo>\\n <mi>R</mi>\\n <mo>+</mo>\\n <mi>γ</mi>\\n <mi>R</mi>\\n <mfenced open=\\\"(\\\" close=\\\")\\\" separators=\\\"|\\\">\\n <mrow>\\n <mi>R</mi>\\n <mo>+</mo>\\n <mi>α</mi>\\n <msup>\\n <mrow>\\n <mi>R</mi>\\n </mrow>\\n <mrow>\\n <mn>2</mn>\\n </mrow>\\n </msup>\\n </mrow>\\n </mfenced>\\n </math>\\n </jats:inline-formula>. Thereafter, we have checked the physical acceptability of the proposed results such as pressure, energy density, energy conditions, <jats:inline-formula>\\n <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\" id=\\\"M8\\\">\\n <mtext>TOV</mtext>\\n </math>\\n </jats:inline-formula> equation, stability conditions, mass function, compactness, and surface redshift by using graphical representation. Moreover, we have investigated that the energy density and radial pressure are nonsingular at the core or free from central singularity and always regular at every interior point of the compact sphere. The numerical values of such parameters along with the surface density, charge to radius ratio, and bag constant are computed for three well-known compact stars such as <jats:inline-formula>\\n <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\" id=\\\"M9\\\">\\n <mfenced open=\\\"(\\\" close=\\\")\\\" separators=\\\"|\\\">\\n <mrow>\\n <mtext>CS1</mtext>\\n </mrow>\\n </mfenced>\\n <mtext>SAXJ</mtext>\\n <mn>1808</mn>\\n <mtext>.</mtext>\\n <mn>4</mn>\\n <mo>−</mo>\\n <mn>3658</mn>\\n </math>\\n </jats:inline-formula> (<jats:inline-formula>\\n <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\" id=\\\"M10\\\">\\n <mfenced open=\\\"(\\\" close=\\\")\\\" separators=\\\"|\\\">\\n <mrow>\\n <mover accent=\\\"true\\\">\\n <mi>x</mi>\\n <mo>˜</mo>\\n </mover>\\n <mo>=</mo>\\n <mn>7.07</mn>\\n <mo> </mo>\\n <mtext>km</mtext>\\n </mrow>\\n </mfenced>\\n </math>\\n </jats:inline-formula>, <jats:inline-formula>\\n <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\" id=\\\"M11\\\">\\n <mfenced open=\\\"(\\\" close=\\\")\\\" separators=\\\"|\\\">\\n <mrow>\\n <mtext>CS2</mtext>\\n </mrow>\\n </mfenced>\\n <mtext>VelaX</mtext>\\n <mo>−</mo>\\n <mn>1</mn>\\n </math>\\n </jats:inline-formula>\\n <jats:inline-formula>\\n <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\" id=\\\"M12\\\">\\n <mfenced open=\\\"(\\\" close=\\\")\\\" separators=\\\"|\\\">\\n <mrow>\\n <mover accent=\\\"true\\\">\\n <mi>x</mi>\\n <mo>˜</mo>\\n </mover>\\n <mo>=</mo>\\n <mn>9.56</mn>\\n <mo> </mo>\\n <mtext>km</mtext>\\n </mrow>\\n </mfenced>\\n </math>\\n </jats:inline-formula>, and <jats:inline-formula>\\n <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\" id=\\\"M13\\\">\\n <mfenced open=\\\"(\\\" close=\\\")\\\" separators=\\\"|\\\">\\n <mrow>\\n <mtext>CS3</mtext>\\n </mrow>\\n </mfenced>\\n <mtext>4U1820</mtext>\\n <mo>−</mo>\\n <mn>30</mn>\\n </math>\\n </jats:inline-formula>\\n <jats:inline-formula>\\n <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\" id=\\\"M14\\\">\\n <mfenced open=\\\"(\\\" close=\\\")\\\" separators=\\\"|\\\">\\n <mrow>\\n <mover accent=\\\"true\\\">\\n <mi>x</mi>\\n <mo>˜</mo>\\n </mover>\\n <mo>=</mo>\\n <mn>10</mn>\\n <mo> </mo>\\n <mtext>km</mtext>\\n </mrow>\\n </mfenced>\\n </math>\\n </jats:inline-formula> and are presented in Tables 1–6. Conclusively, we have noticed that our presented charged compact stellar object in the background of two well-known <jats:inline-formula>\\n <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\" id=\\\"M15\\\">\\n <mi>f</mi>\\n <mfenced open=\\\"(\\\" close=\\\")\\\" separators=\\\"|\\\">\\n <mrow>\\n <mi>R</mi>\\n </mrow>\\n </mfenced>\\n </math>\\n </jats:inline-formula> models obeys all the necessary conditions for the stable equilibrium position and which is also perfectly fit to compose the strange quark star object.</jats:p>\",\"PeriodicalId\":48962,\"journal\":{\"name\":\"Advances in Astronomy\",\"volume\":\" \",\"pages\":\"\"},\"PeriodicalIF\":1.6000,\"publicationDate\":\"2021-01-02\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"3\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Advances in Astronomy\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://doi.org/10.1155/2021/6698208\",\"RegionNum\":4,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"ASTRONOMY & ASTROPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Advances in Astronomy","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1155/2021/6698208","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
Model of Charged Anisotropic Strange Stars in Minimally Coupled
f
R
Gravity
In the present article, we have investigated a new family of nonsingular solutions of static relativistic compact sphere which incorporates the characteristics of anisotropic fluid and electromagnetic field in the context of minimally coupled theory of gravity. The strange matter bag model equation of state (EoS) has been considered along with the usual forms of the Karori–Barua metric potentials. For this purpose, we derived the Einstein–Maxwell field equations in the assistance of strange matter EoS and type ansatz by employing the two viable and cosmologically well-consistent models of and . Thereafter, we have checked the physical acceptability of the proposed results such as pressure, energy density, energy conditions, equation, stability conditions, mass function, compactness, and surface redshift by using graphical representation. Moreover, we have investigated that the energy density and radial pressure are nonsingular at the core or free from central singularity and always regular at every interior point of the compact sphere. The numerical values of such parameters along with the surface density, charge to radius ratio, and bag constant are computed for three well-known compact stars such as (, , and and are presented in Tables 1–6. Conclusively, we have noticed that our presented charged compact stellar object in the background of two well-known models obeys all the necessary conditions for the stable equilibrium position and which is also perfectly fit to compose the strange quark star object.
期刊介绍:
Advances in Astronomy publishes articles in all areas of astronomy, astrophysics, and cosmology. The journal accepts both observational and theoretical investigations into celestial objects and the wider universe, as well as the reports of new methods and instrumentation for their study.