Constant-roll Inflation in $F(R)$ Gravity

Abstract

We propose the study of constant-roll inflation in $F(R)$ gravity. We use two different approaches, one that relates an $F(R)$ gravity to well known scalar models of constant-roll and a second that examines directly the constant-roll condition in $F(R)$ gravity. With regards to the first approach, by using well known techniques, we find the $F(R)$ gravity which realizes a given constant-roll evolution in the scalar-tensor theory. We also perform a conformal transformation in the resulting $F(R)$ gravity and we find the Einstein frame counterpart theory. As we demonstrate, the resulting scalar potential is different in comparison to the original scalar constant-roll case, and the same applies for the corresponding observational indices. Moreover, we discuss how cosmological evolutions that can realize constant-roll to constant-roll eras transitions in the scalar-tensor description, can be realized by vacuum $F(R)$ gravity. With regards to the second approach, we examine directly the effects of the constant-roll condition on the inflationary dynamics of vacuum $F(R)$ gravity. We present in detail the formalism of constant-roll $F(R)$ gravity inflationary dynamics and we discuss how the inflationary indices become in this case. We use two well known $F(R)$ gravities in order to illustrate our findings, the $R^2$ model and a power-law $F(R)$ gravity in vacuum. As we demonstrate, in both cases the parameter space is enlarged in comparison to the slow-roll counterparts of the models, and in effect, the models can also be compatible with the observational data. Finally, we briefly address the graceful exit issue.

CQG accepted

References in corpus (15)

• Unified cosmic history in modified gravity: from F(R) theory to Lorentz non-invariant models
• The Standard Model Higgs boson as the inflaton
• Modified f(R) gravity consistent with realistic cosmology: from matter dominated epoch to dark energy universe
• Primordial Non-Gaussianities from Inflation Models
• Inflationary Cosmology
• de Sitter space and the equivalence between f(R) and scalar-tensor gravity
• $f(R)$ constant-roll inflation
• Constant-roll inflation: confrontation with recent observational data
• Inflationary $\alpha$-attractors from $F(R)$ Gravity
• Deceleration versus Acceleration Universe in Different Frames of $F(R)$ Gravity
• Viable Mimetic Completion of Unified Inflation-Dark Energy Evolution in Modified Gravity
• Inflation over the hill
• Inflation with a Smooth Constant-Roll to Constant-Roll Era Transition
• Inflationary Dynamics with a Smooth Slow-Roll to Constant-Roll Era Transition
• Features from the non-attractor beginning of inflation

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