Gravity and Structure of Universe

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As to the structure of universe, there are two kinds of problem, that is, "global" and "local". Global structure implies an overall structure beyond the present horizon ahd this problem is related to a scenario of quantum creation of universe and the Inflation afte that. Local structure comprises problems on generation of density perturbation and recognition of the present density structure for dark matter as well as for baryon matter. On the other hand, trial of the unified theory including gravity such as the string theory has indicated a modifiction of the general relativity, which might affect the process near the creation of universe. Considering these situations, this research project was organised in order to study these two aspects of the structure in relation to the theory of gravity.The subjects stdied in this project include the followings. Quantum Cosmology : Schrodinger like formulation of the Wheeler-DeWitt equation through an introduction of the cosmic-time variables, quantum black hole. Lagrangian with R^2 : New effects for chaotic inflation, black hole structure, nonlinear gravitational wave Universe models : higher dimensional mixmaster model, Nariai metric and Kantowski metric Inflation : chaotic inflation of closed models, baryon number generation during the inflation stage, generation of curveture fluctuation and separation of particle and antiparticles at the reheating phase. Dark matter and nucleosynthesis : lepton number and He, Li abundance, spectrum modification of the cosmic background by decaying particles Structure formation : growth of isothermal perturbation in gauge-invariant theory, galaxy formation by cosmic string and rotation velocity of spiral galaxy, comparison of IRAS data with universe models containing decaying particles and cosmological constant.