Formalizing Slow-Roll Inflation in Scalar-Tensor Theories of Gravitation
Published in Physics of the Dark Universe, 2020
Recommended citation: Akın, K., Arapoğlu A. S., Yükselci, A. E. (2020). "Slow-Roll Inflation in Scalar-Tensor Theories of Gravitation" Physics of the Dark Universe.
The viability of slow-roll approximation is examined by considering the structure of phase spaces in scalar-tensor theories of gravitation and the analysis is exemplified with a nonminimally coupled scalar field to the spacetime curvature. The slow-roll field equations are obtained in the Jordan frame in two ways: first using the direct generalization of the slow-roll conditions in the minimal coupling case to nonminimal one, and second, conformal transforming the slow-roll field equations in the Einstein frame to the Jordan frame and then applying the generalized slow-roll conditions. Two inflationary models governed by the potentials $ V(\phi) \propto \phi^2 $ and $ V(\phi) \propto \phi^4 $ are considered to compare the outcomes of two methods based on the analysis of $n_s$ and $r$ values in the light of recent observational data.
Paper: Journal Version arXiv
Recommended citation: Akın, K., Arapoğlu A. S., Yükselci, A. E. (2020). “Slow-Roll Inflation in Scalar-Tensor Theories of Gravitation” Physics of the Dark Universe .