银河系中心存在一个由中心大质量黑洞和一些近邻恒星组成的相对论性动力学系统。它是目前唯一可以精确测量单个恒星运动并被长期监测的星系核区。大质量黑洞近邻区域的恒星轨道运动受黑洞的相对论势场影响从而可以作为测定中心黑洞度规无与伦比的探针。因此，银河系中心为人们研究星系中心大质量黑洞周围恒星的相对论性动力学、测量黑洞度规和检验引力理论提供了独一无二的实验室。在本项目申请书中我们计划研究银心大质量黑洞周围恒星的相对论性动力学及其轨道的长期演化，通过这些恒星的观测统计性质限制并确定它们的起源，探索银心大质量黑洞周围S0-2及S0-102轨道以内的恒星、中子星甚至是恒星级黑洞的分布，甄别相对论效应与周围背景恒星扰动的差异，研究如何建立一有效模型利用观测到的这些恒星的轨道和运动来提取中心黑洞的度规参量并检验引力理论。

The Galactic Center (GC) is a unique relativistic dynamical system, composed of a central massive black hole (MBH) and its surrounding stars, where the motion of individual stars can be accurately measured and have been monitored for many years. The kinematics of those stars rotating in the vicinity of the central MBH is controlled by the relativistic potential of the MBH and is a superb tool for studying the relativistic dynamics, measuring the MBH metric, and testing the gravity theory. In this proposal, we plan to study the relativistic dynamics of those stars in the vicinity of the MBH in the GC and the secular evolution of their orbits, to figure out the origin of those stars through their observational properties, to distinguish the relativistic effects on the stellar orbits from those caused by the perturbation of background stars, to explore the existence and the distribution of pulsars, neutron stars, and stellar-mass black holes in the vicinity of the MBH, and to construct an effective model, based on fully relativistic and post-Newtonian calculations and Markov Chain Monte-Carlo methods, to extract fundamental parameters of the MBH metric and test gravity theory.