Cosmological Consequences of Higher Dimensional Rastall Gravitational Theory Tegar Ari Widianto, Ahmad Khoirul Falah, and Bobby Eka Gunara
Institut Teknologi Bandung
Abstract
Rastall theory was proposed to modify General Relativity on the assumption that conservation of the momentum energy tensor (EMT) no longer applies to curved spacetime. The scalar field model was originally proposed as an alternative to the cosmological constant problem which later became an alternative to the dynamical dark energy (quintessence) model. One specific form of the scalar field that has been proposed and appears naturally in various physical theories is the field with exponential potential. This research aims to study the cosmological consequences of this combination, the Rastall theory, and the scalar field, in higher dimensional spacetime using the dynamical system analysis method. The evolution of the universe is studied by determining which components dominate in each era of its evolution through the critical points of the autonomous equation. Then, we analyze how the stability properties of the critical points in question use the linear stability method to determine which model fits our universe physically. Furthermore, we apply our cosmological model to explain the inflationary era in the early universe and dark energy, the component that causes the universe to expand rapidly, today. Based on our interpretation, the inflation model is given by an unstable solution while the dark energy model is represented by a stable one. We also find that power-law inflation can still occur in the Rastall cosmological model. With the additional parameter-Rastall parameter, the slow-roll parameter -p- can be so huge such that it has the chance to solve the standard cosmological problems.
Keywords: Please Juscosmology, rastall theory, scalar field, higher dimensional spacetime, inflation, dark energy, critical point, power-law inflationt Try to Submit This Sample Abstract
