Dynamics of fast spinning neutron stars around a black hole

强束缚引力系统经常表现出有趣的动力学现象。在重力中旋转有限大小的物体不会遵循时空流形中的测地线。由于各种相对论耦合，一颗快速自转的中子星或围绕黑洞运行的中子星双星系统将表现出复杂的自旋和轨道行为。这个项目研究了两类特殊的这样的系统：(1)围绕黑洞运行的快速旋转的NS系统，以及(2)围绕黑洞运行的双中子星系统(这是一个分级的三体系统)。在(1)中，除了中子星自旋的De-Sitter和Lense-Thirring进动外，自旋-曲率耦合导致非平面的NS轨道。(2)轨道-轨道耦合产生重磁效应，表现为双中子星系统的复杂轨道运动和自旋运动。射电脉冲星计时和引力波观测将能够研究这些系统的动力学特性。黑洞-中子星系统在基础物理学和天体物理学的研究中很有用。它们可以用来绘制黑洞周围的时空结构图，并确定星系中大质量核黑洞的质量和自转。这是一个理论项目。它涉及唯象建模、代数计算和数值计算。

Strongly bound gravitational systems often show interesting dynamical phenomena. Spinning finite-size objects in gravity would not follow geodesics in a space-time manifold. A fast spinning neutron stars or a neutron-star binary system orbiting around a black hole would exhibit complex spin and orbital behaviours due to various relativistic coupling. This project investigates two special classes of such systems: (1) a fast spinning NS orbiting around a BH, and (2) a double neutron-star system orbiting around a BH (which is a hierarchical 3-body system). In (1) spin-curvature coupling leads to non-planar NS orbits, in addition to de-Sitter and Lense-Thirring precessions of the neutron star's spin. In (2) orbit-orbit coupling induces gravito-magnetism, which manifests in the complex orbital and spin motion of the double neutron-star system. Radio pulsar timing and gravitational wave observations will be able to study the dynamical properties of these systems. Black hole - neutron star systems are useful in the study of fundamental physics and in astrophysics. They can be used to map the space-time structure around black holes and to determine the masses and spins of the massive nuclear black holes in galaxies. This is a theoretical project. It involves phenomenological modelling, algebraic computation and numerical calculations.