Abstract:
In this thesis, we studied two different phenomena. In the first part,
the accelerated expansion of the universe without introducing the
concept of dark energy was examined. We studied it in the FRW
metric with perfect and non-perfect fluid, as well as the KantowskiSachs Space-Time and F (R) Gravity models. We confirmed that
geometry has an impact on the accelerated expansion of the universe.
In the second part, the effect of gravitational force on entanglement is
explored, where the elaboration of a general formalism for quantum
spin entanglement in curved space-time is presented. This formulation
permits the study of different models in curved space-time. The
Schwarzschild-de Sitter Space-Time was investigated as well by
inspecting the role of the cosmological constant and its influence on
entanglement. The Kerr and the Reissner-Nordström models are also
considered, where the effect of the non-commutativity of space as
well as black hole rotation on entanglement are discussed by using
concurrence and the spin entanglement of a system of two spin-1/2
particles. With particularity, it contains multiple and various physical
parameters, allowing for a detailed study of this purely quantum
phenomenon in different frames of space and geometry or both at the
same time.
