标题： 使用黑洞周围的球对称吸积比较替代时空 显示英文标题

标题： The comparison of alternative spacetimes using the spherical accretion around the black hole

摘要： 在引力场较强的区域，我们研究了不同重力对由于球形吸积形成的吸积盘的影响。 为了实现这一点，我们获得了GRH方程的数值解，利用了Schwarzschild、Kerr、Einstein-Gauss-Bonnet和Hartle-Thorne时空度规。 我们研究了黑洞的旋转参数（a/M）、EGB耦合常数（$\alpha$）以及旋转黑洞的四极矩（q）对在强场中形成的吸积盘的影响。 分别研究了缓慢旋转和快速旋转黑洞模型的盘形成，并进行了比较。 我们的数值模拟显示，在特定条件下，从Hartle-Thorne引力得出的解趋近于从Kerr和其他引力模型得到的解。 在缓慢旋转黑洞的背景下，当$a/M=0.28$时，在0 < q < 0.5范围内，Hartle-Thorne结果与Kerr结果有良好的一致性。 相反，在快速旋转黑洞的情况下，在0.5 < q < 1范围内，Hartle-Thorne结果更明显地与q=1的值一致。 然而，对于q > 1的情况，很明显Hartle-Thorne解与所有引力模型提供的解存在差异。 我们在此的动机是首次在黑洞的GRH方程数值解中使用Hartle-Thorne时空度规，将结果与其他引力的结果进行比较，并确定在哪些条件下Hartle-Thorne解与已知的黑洞时空度规解相容。 这可能使我们能够提供一种替代的观点来解释观测到的X射线数据。 显示英文摘要

摘要： In the region where the gravitational field is strong, we have examined the influence of different gravities on the accretion disk formed due to spherical accretion. To achieve this, we obtain numerical solutions of the GRH equations, utilizing Schwarzschild, Kerr, Einstein-Gauss-Bonnet, and Hartle-Thorne spacetime metrics. We investigate the impact of the rotation parameter of a black hole (a/M), the EGB coupling constant ($\alpha$), and the quadrupole moment of the rotating black hole (q) on the accretion disk formed in a strong field. The formation of the disk for the slowly and rapidly rotating black hole models is separately examined, and comparisons are made. Our numerical simulations reveal that, under the specific conditions, the solution derived from Hartle-Thorne gravity converges towards solutions obtained from Kerr and other gravitational models. In the context of the slowly rotating black hole with $a/M=0.28$, we observe a favorable agreement between the Hartle-Thorne result and the Kerr result within the range of 0 < q < 0.5. Conversely, in the scenario of the rapidly rotating black hole, a more pronounced alignment with the value of q=1 is evident within the range of 0.5 < q < 1. Nevertheless, for q > 1, it becomes apparent that the Hartle-Thorne solution diverges from solutions provided by all gravitational models. Our motivation here is to utilize the Hartle-Thorne spacetime metric for the first time in the numerical solutions of the GRH equations for the black holes, compare the results with those obtained using other gravities, and identify under which conditions the Hartle-Thorne solution is compatible with known black hole spacetime metric solutions. This may allow us to provide an alternative perspective in explaining observed X-ray data.