Gravitational Constraint Effects In General Relativity

It is meaningful for astrophysics to study gravitational effects in General Rel-ativity. The gravitational properties of massive celestial body consists of the inter-nal properties and external properties of gravitational field. Besides gravitational properties, there’s thermodynamical properties in the internal field. External field properties includes the motion of test particle in the geodesic and the radiant properties of accretion disks. In this paper the author studied relevant work of two published paper [8,9] by him. The thesis is divided into six chapters.In chapter one, we introduced several gravitational effects in General Rela-tivity briefly and why we should study the gravitational effects. Then we studied the solution for the wave equation of charged mass point in Quantum Mechanics. We deduced magnetic monopole could exist in nature from the singularity of the solution and finally deduced neutron star could have plenty of magnetic monopole using Rubakov-Callan model.In chapter two, we studied the constraint classical Schwarzschild black hole placed on the test particle moving on its geodesics. The orbit of test particle should satisfy request of real movement and stability of radial movement. There-fore,circular orbits close to source of the field is not stable against perturbation.In chapter three, we studied the constraint Kerr black hole placed on its orbit. State of test particle depends on direction of its movement and circumambulation direction relative to source of mass. Calculation indicates that compared to parti-cles circumambulate negatively, particles circumambulate positively have smaller radius of orbit. Particles of different circumambulate directions will separate fi-nally.In chapter four, we get properties of Bose gas and Fermi gas from calculation of thermodynamic equation of neutron star. From state equation of neutron star we get structure equation of neutron star. Nuclear reaction placed restriction on mass of neutron star. A massive neutron star would turn into black hole whereas a neutron with too small mass could not exist because degeneracy pressure is stronger than gravitation. In this way we acquire the upper limits and lower limits of mass of neutron star.Chapter five studied constraint magnetic monopoles placed on mass-radius ratio of neutron star. Using the structure equation of neutron stars we obtain upper limit and lower limit of mass-radius ratio for magnetic charged neutron star. Then we calculated stability of neutron star with minimum mass-radius ratio.In chapter six, we study circular timelike geodesics in the spacetime of a black hole including global monopole. We show that when the range of parameter changed the properties of the circular geodesics and the radiation of accretion disks are different. It follows that the properties of the accretion disk around black hole including global monopole can be different from that of a disk around Schwarzschild black hole. Black hole including global monopole and Schwarzschild black hole can be distinguished from their radiation spectrum of accretion disks.