The Study Of Distribution For Axion Dark Matter On Galaxies And Black Holes Background

Abstract:Astronomical observations show that dark matter may exist in the universe, and it is a major part of the universe, this matter also play an important role for the structure formation of the universe. Study of the dark matter is an important topic in astrophysics and particle physics. At present, the specific composition of dark matter is not very clear, therefore, many theoretical predictions of the dark matter are produced. The axion is one of the candidates of dark matter, it is may be a boson with small mass and is produced in QCD phase transition of early universe.The axion is a research object in this thesis. At first, the relationship between the rotation velocity of celestial bodies around the centre of galaxies and the distance from certre is studied in chapter4, and their relationship diagrams were maked. At the same time, Rubin’s actual observations were regarded as a reference. There are four cases were considered in this thesis:When the chemical potential is zero, the angular quantum number was taken as l=0or l=1; when the chemical potential is not zero, the same quantum numbers were considered as above case. The result shown that theoretical calculation conforms qualitatively with an actual observation; when the chemical potential is not zero, only the case of l=1consists qualitatively with the actual observation. In addition, the physics meaning of these results were analyzed and discussed.The distribution law of the axion dark matter on several black holes background are studied in chapter5, the density distribution of axion in two dimensional charged point mass black hole and four dimensional charged black hole were calculated respectively, the density distribution of axion in four dimensional string black hole was also calculated, the calculation results were discussed and analyzed. Moreover, the density distribution and correlation function of axion in de Sitter and anti de Sitter space were also calculated, the impact of chemical potential and cosmological constant on correlation effects were discussed.The new work of this paper as follows:1. The influence of axion dark matter with chemical potential to rotation curves of galaxies is analyzed in chapter4.2. The condensation equation of Popov on curve space-time was derived in chapter5, the density distribution of axion in two dimensional point mass black hole、four dimensional charged black hole and four dimensional dilation black hole were calculated. Moreover, the density distribution law was discussed and analyzed.3. The density distribution of axion in three dimensional and four dimensional de Sitter and anti de Sitter space were calculated in chapter5, and the asymptotic correlation functions of axion were also calculated.