TY  - BOOK
AU  - Samah Nabil Abuelhamd Osman
AU  - Mamdouh Isaac Wanas , 
TI  - f(R) or  f(T)-Theories : : Unification Priciple and Problems of Standard Cosmology / 
PY  - 2017///
CY  - Cairo : 
PB  - Samah Nabil Abuelhamd Osman , 
KW  - f(R) or  f(T)-Theories
KW  - Standard cosmology problems
KW  - Unification Priciple
N1  - Thesis (Ph.D.) - Cairo University - Faculty of Science - Department of Astronomy and Meteorology; Issued also as CD
N2  - It is known that standard cosmology su{uFB00}ers from some problems. Among suggested solutions are f(R) and f(T) theories in which energy-momentum distri- bution is described by a phenomenological second order tensor. In a version of absolute parallelism (AP-) geometry, a pure geometric {uFB01}eld theory is constructed in the context of the Uni{uFB01}cation Principle. This principle guarantees writing every quantity in the theory using the building blocks (BB) of the AP-geometry only. Physical analysis of the theory shows that the theory represents a uni{uFB01}ed gravity and electromagnetic {uFB01}eld. Geometric expressions for Poisson equation for gravity and electromagnetic {uFB01}elds are obtained. Also, we show that the suggested theory has a successful GR-limit. A general di{uFB00}erential identity is derived in a modi{uFB01}ed version of AP-geometry. The importance of this di{uFB00}erential identity is its relation to conservation in the context of geometrization philosophy. Applications of the suggested theory in the domain of cosmology, satisfying the cosmological principle, solve {uFB02}atness and particle horizons problems
UR  - http://172.23.153.220/th.pdf
ER  -