![]() | Only 14 pages are availabe for public view |
Abstract The thesis contains three Chapters. It contains also a list of abbrevia- tions, symbols, tables and a list of references and an English and Arabic summary. The references in the list are arranged alphabetically and enu- merated consequently. Chapter I: Field Theories in Riemannian Geometry and their Cosmological Applications This Chapter reviews briefly the general theory of relativity (GR), the standard theory of gravity. Also, it reviews FRW- standard cosmology. Some problems of GR in the domain of cosmology are reviewed. Also, it contains an alternative theory of gravity, f(R) gravity theory, that is constructed in the context of Riemannian geometry. Moreover, we review a contribution of f(R) to interpret the accelerating expansion of the Universe. Chapter II: Field Theories in The AP-Geometry and Their Cosmology This Chapter, gives a brief account on a more wider geometry than the Riemannian geometry, the AP-geometry. Also we review two theories constructed in this version of geometry. These are the teleparallel equivalence of general relativity vii (TEGR) and f(T) theories. Moreover, it contains standard and non-standard cosmological application performed in the context of f(T) theories. Chapter III: A Suggested Field Theory in The PAP-Geometry In this chapter, we give a brief account on PAP-geometry. Also, we give a new field theory constructed in the context of the PAP-geometry. The field equations are derived using the differential identity method. The theory used is a pure geometric one. We have used three schemes to extracting physical meaning of the geometric objects included in the field theory. A spherical symmetric solution of the field equations of the suggested theory is obtained. This solution gives rise to the Schwarzchild exterior field. In this thesis Sections are enumerated from 1 to 17, along the thesis, while equations are enumerated after the Section number. Tables and Figures are enumerated after the Chapter number. |