18,687 research outputs found

    Behaviour of spin-half particles in curved space-time

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    We study the behaviour of spin-half particles in curved space-time. Since Dirac equation gives the dynamics of spin-half particles, we mainly study the Dirac equation in Schwarzschild, Kerr, Reissner-Nordstr\"om geometry. Due to the consideration of existence of black hole in space-time (the curved space-time), particles are influenced and equation will be modified. As a result the solution will be changed from that due to flat space.Comment: 2 Latex pages, World Scientific Style; ws-p9-75x6-50.cls; To appear in the Proceedings of 9th Marcel Grossman Meeting, Rome, 2000 (World Scientific

    Nucleosynthesis Around Black Holes

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    Study of nucleosynthesis in accretion disks around black holes was initiated by Chakrabarti et al. (1987). In the present work we do the similar analysis using the state-of-the-art disk model, namely, Advective Accretion Disks. During the infall, matter temperature and density are generally increased which are first computed. These quantities are used to obtain local changes in composition, amount of nuclear energy released or absorbed, etc. under various inflow conditions. In the cases where the magnetic viscosity is dominant neutron torus may be formed. We also talk about the fate of Li^7 and D during the accretion. The outflowing winds from the disk could carry the new isotopes produced by nucleosynthesis and contaminate the surroundings. From the degree of contamination, one could pinpoint the inflow parameters.Comment: 9 Latex pages and 2 Figures. crckapb.st