Charged anisotropic matter with linear or nonlinear equation of state
Victor Varela, Farook Rahaman, Saibal Ray, Koushik Chakraborty, Mehedi Kalam
备注：
22 Latex pages, 17 figures, Inclusion of new paragraph at the end of Conclusion & some of the old captions of the Figures are replaced with new captions
Ivanov pointed out substantial analytical difficulties associated with self-gravitating, static, isotropic fluid spheres when pressure explicitly depends on matter density. Simplification achieved with the introduction of electric charge were noticed as well. We deal with self-gravitating, charged, anisotropic fluids and get even more flexibility in solving the Einstein-Maxwell equations. In order to discuss analytical solutions we extend Krori and Barua's method to include pressure anisotropy and linear or non-linear equations of state. The field equations are reduced to a system of three algebraic equations for the anisotropic pressures as well as matter and electrostatic energy densities. Attention is paid to compact sources characterized by positive matter density and positive radial pressure. Arising solutions satisfy the energy conditions of general relativity. Spheres with vanishing net charge contain fluid elements with unbounded proper charge density located at the fluid-vacuum interface. Notably the electric force acting on these fluid elements is finite, although the acting electric field is zero. Net charges can be huge ($10^{19}\,C$) and maximum electric field intensities are very large ($10^{23}-10^{24}\,statvolt/cm$) even in the case of zero net charge. Inward-directed fluid forces caused by pressure anisotropy may allow equilibrium configurations with larger net charges and electric field intensities than those found in studies of charged isotropic fluids. Links of these results with charged strange quark stars as well as models of dark matter including massive charged particles are highlighted. The van der Waals equation of state leading to matter densities constrained by cubic polynomial equations is briefly considered. The fundamental question of stability is left open.
Dissipative Spherical Collapse of Charged Anisotropic Fluid in f(R) Gravity
本文研究了一个可行的模型f（R）= R + αR^n与电磁场的联合作用对引力坍缩不稳定性范围的影响。我们假设带电各向异性流体通过热流耗散能量，讨论了局部各向异性背景可以包含天体上的电磁场、密度不均匀性、剪切和相变。动力学方程有助于研究自引力天体的演化，并得出绝热指数依赖于电磁背景、天体质量和半径的结论。
Rotating and non-linear magnetic-charged black hole with an anisotropic matter field
School of Physics Science and Technology, Xinjiang University（新疆大学物理科学与技术学院）；Faculty of Science, Kunming University of Science and Technology（昆明理工大学理学院）
Charged anisotropic white dwarfs in $f\left({R}, {T}\right)$ gravity
CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences（中国科学院理论物理研究所）；School of Physical Sciences, University of Chinese Academy of Sciences（中国科学院大学）；Hohai University（河海大学）
Karmarkar-Tolman Embedded Charged Anisotropic Stars in f(R) Gravity
School of Physics and Electronics, Hunan University（湖南大学物理与电子学院）；Institute of Physics, Gomal University（戈尔姆大学物理研究所）；Hunan Provincial Key Laboratory of High-Energy Scale Physics and Applications, Hunan University（湖南大学高能标物理与应用湖南省重点实验室）
Physical Features of Geometrically Deformed Anisotropic Charged Three-dimensional BTZ Black Holes
Institute of Mathematics, University of the Punjab（旁遮普大学数学研究所）；Faculty of Symbiotic Systems Science, Fukushima University（福岛大学共生系统科学学院）；Department of Mathematics, College of Science, King Saud University（国王沙特大学理学院数学系）；Department of Mathematics, Quaid-i-Azam University（真纳大学数学系）；Research Center of Astrophysics and Cosmology, Khazar University（哈扎尔大学天体物理学与宇宙学研究中心）
Charged black holes embedded in matter with anisotropic pressure: Horizon Structure and Quasinormal Mode Spectra
Illinois Center for Advanced Studies of the Universe, University of Illinois Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校宇宙高级研究中心）；Center for AstroPhysical Surveys, National Center for Supercomputing Applications, University of Illinois Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校国家超级计算应用中心天体物理调查中心）；Department of Astronomy, University of Illinois Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校天文系）
本文从多方状态方程出发，研究了各向异性压力和电磁场作用下的Einstein-麦克斯韦方程组。场方程的新的精确解是根据初等函数生成的。Feroze和Siddiqui（Gen Relativ Gravit 43：1025，2011）和Maharaj和Mafa Takisa（Gen Relativ Gravit 44：1419，2012）的不带电溶液的特殊情况被恢复。从一般的处理中，我们也得到了中性各向异性引力体的多面体的精确解。图形显示，能量密度，切向压力和各向异性的配置文件是一致的，与早期的治疗，这表明在描述相对论性致密星的相关性。
