Formalizing Slow-roll Inflation in Scalar-Tensor Theories of Gravitation

Abstract

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 $V(\varphi )\propto {\varphi }^2$ and $V(\varphi )\propto {\varphi }^4$ 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.

19 pages, 5 figures. arXiv admin note: text overlap with arXiv:1504.02192

References in corpus (5)

• Frame-dependence of higher-order inflationary observables in scalar-tensor theories
• Non-Minimal Two-Loop Inflation
• Inflationary Parameters in Renormalization Group Improved ${\varphi }^4$ Theory
• Consistency of equations of motion in conformal frames
• Higgs Inflation with linear and quadratic curvature corrections

Cited by in corpus (10)

• On the number of $e$-folds in the Jordan and Einstein frames
• New slow-roll approximations for inflation in Einstein-Gauss-Bonnet gravity
• Slow-Roll Inflation in the Jordan Frame
• Global Portraits of Nonminimal Inflation: Metric and Palatini
• The Effect of Non-minimally Coupled Scalar Field on Gravitational Waves from First-order Vacuum Phase Transitions
• More accurate slow-roll approximations for inflation in scalar-tensor theories
• Holographic inflation and holographic dark energy from entropy of the anti-de Sitter black hole
• Global portraits of nonminimal inflation
• Evolution of the early universe in Einstein-Cartan theory
• Global Portraits of Inflation in Nonsingular Variables