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Formation of galaxies in cosmological models /

Nouran Essam Eldien Abdelhamid Ibrahim

Formation of galaxies in cosmological models / تكون المجرات فى النماذج الكونيه Nouran Essameldien Abdelhamid Ibrahim ; Supervised Mamdouh Isaac Wanas , Gamal Bakr Ali - Cairo : Nouran Essam Eldien Abdelhamid Ibrahim , 2020 - 156 P . : 25cm

Thesis (M.Sc.) - Cairo University - Faculty of Science - Department of Astronomy and Meterology

This thesis represents an attempt to start tackling formation of galax- ies in world models. It aims to study formation of condensations in models in the standard cosmology. This is because the formation of condensation in standard cosmology is a very difficult subject. We begin this study by reviewing briefly the general theory of rela- tivity (GR) and the cosmological principle, the basis necessary to start standard cosmology. This part is terminated by discussing the main problems of standard cosmology. In the second part of this thesis, we reviewed briefly one of the old problems of standard cosmology, the apparent constancy of the density of matter-energy in the Universe. We reviewed an attempt to solve this problem by modifying Gr field equations.The attempt contains how to modify the cosmological principle to the perfect cosmological principle to account for continuous creation of matter (violation of the law of conservation). In place of the field equations of GR, we reviewed the equations of the modified theory, the steady state theory. We showed how forma- tion of condensations is tackled in this type of cosmology, the steady state cosmology. We showed that how at the end of sixties and the beginning of the seventies of the last century, the interest in the steady state cosmology decreased and the interest of the big-bang standard cosmology becomes great again. The third part of this thesis we include the use of a pure geometric field theory to construct a new cosmological model. The model ob- tained is free from two of standard cosmology problems: flatness prob- lem and the particle horizons problem. We attempted in this part, to examine formation of condensations in the new model. This attempt still need big efforts to be concluded. The use of pure geometric field theories enabled us to remove most if not all the problems of standard cosmology



Cosmological models Formation of galaxies Standard cosmology