论文标题
新的各向异性星溶液中的模拟重力
New anisotropic star solutions in mimetic gravity
论文作者
论文摘要
我们通过将托尔曼 - 丝裂度量和不直接依赖于它的特定各向异性应用于模拟重力的框架中提取新类别的各向异性溶液，并通过将内部各向异性溶液平滑匹配到Schwarzschild溶液中。然后，为了提供透明图片，我们使用4U 1608-52 PULSAR的数据。我们研究能量密度以及径向压力和切向压力的轮廓，我们表明它们都是正面的，并且朝着恒星的中心降低。此外，我们研究了半径的增加功能，这两者都意味着后者是排斥的。另外，通过检查径向和切向方程参数，我们表明它们在单调上增加，而不是对应于外来物质。关于度量电位，我们发现它们没有奇异性，无论是在恒星的中心还是在边界处。此外，我们验证所有能量条件都得到满足，我们证明了径向和切向声速度的正方形是正和亚亮体的，我们发现表面红移满足了理论要求。最后，为了研究稳定性，我们应用了Tolman-Oppenheimer-Volkoff方程，我们执行绝热指数分析，并检查静态情况，表明在所有情况下，恒星都是稳定的。
We extract new classes of anisotropic solutions in the framework of mimetic gravity, by applying the Tolman-Finch-Skea metric and a specific anisotropy not directly depending on it, and by matching smoothly the interior anisotropic solution to the Schwarzschild exterior one. Then, in order to provide a transparent picture we use the data from the 4U 1608-52 pulsar. We study the profile of the energy density, as well as the radial and tangential pressures, and we show that they are all positive and decrease towards the center of the star. Furthermore, we investigate the anisotropy parameter and the anisotropic force, that are both increasing functions of the radius, which implies that the latter is repulsive. Additionally, by examining the radial and tangential equation-of-state parameters, we show that they are monotonically increasing, not corresponding to exotic matter. Concerning the metric potentials we find that they have no singularity, either at the center of the star or at the boundary. Furthermore, we verify that all energy conditions are satisfied, we show that the radial and tangential sound speed squares are positive and sub-luminal, and we find that the surface redshift satisfies the theoretical requirement. Finally, in order to investigate the stability we apply the Tolman-Oppenheimer-Volkoff equation, we perform the adiabatic index analysis, and we examine the static case, showing that in all cases the star is stable.
