Systematics of constant roll inflation

  title={Systematics of constant roll inflation},
  author={Lilia Anguelova and P{\'e}ter Sur{\'a}nyi and L. C. Rohana Wijewardhana},
  journal={Journal of Cosmology and Astroparticle Physics},
  pages={004 - 004}
We study constant roll inflation systematically. This is a regime, in which the slow roll approximation can be violated. It has long been thought that this approximation is necessary for agreement with observations. However, recently it was understood that there can be inflationary models with a constant, and not necessarily small, rate of roll that are both stable and compatible with the observational constraint ns ≈ 1. We investigate systematically the condition for such a constant-roll… 

Figures from this paper

On Non-slow Roll Inflationary Regimes

We summarize our work on constant roll inflationary models. It was understood recently that constant roll inflation, in a regime beyond the slow roll approximation, can give models that are in

Constant roll warm inflation in high dissipative regime

Constant-roll warm inflation is introduced in this work. A novel approach to finding an exact solution for Friedman equations in the constant-roll framework is presented for cold inflation and is

Observational constraints on constant roll inflation

Constant-roll inflation was recently introduced by Motohashi, Starobinsky and Yokoyama as a phenomenological way to parametrize deviations from the slow-roll scenarios. In this paper, we investigate

Constant-roll (quasi-)linear inflation

In constant-roll inflation, the scalar field that drives the accelerated expansion of the Universe is rolling down its potential at a constant rate. Within this framework, we highlight the relations

Dynamical analysis of attractor behavior in constant roll inflation

There has been considerable recent interest in a new class of non-slow roll inflationary solutions known as constant roll inflation. Constant roll solutions are a generalization of the ultra-slow

Tachyon constant-roll inflation

The constant-roll inflation is studied where the inflaton is taken as a tachyon field. Based on this approach, the second slow-roll parameter is taken as a constant which leads to a differential

Large- η constant-roll inflation is never an attractor

Slow roll solutions to inflationary potentials have been widely believed to be the only universal attractor. Over the last few years there has been growing interest in a new class of inflationary

Constant-roll k-inflation dynamics

In this work we shall investigate the phenomenological implications of the constant-roll condition on a k-Inflation theory of gravity. The latter theories are particularly promising, since these

Constant-roll tachyon inflation and observational constraints

For the constant-roll tachyon inflation, we derive the analytical expressions for the scalar and tensor power spectra, the scalar and tensor spectral tilts and the tensor to scalar ratio to the first



Inflation with a constant rate of roll

We consider an inflationary scenario where the rate of inflaton roll defined by ̈ϕ/H ϕ̇ remains constant. The rate of roll is small for slow-roll inflation, while a generic rate of roll leads to the

Inflation with a smooth constant-roll to constant-roll era transition

In this paper we study canonical scalar field models with a varying second slow-roll parameter, that allow transitions between constant-roll eras. In the models with two constant-roll eras it is

Inflationary dynamics with a smooth slow-roll to constant-roll era transition

The theoretical implications of having a varying second slow-roll index on the canonical scalar field inflationary dynamics are investigated and various illustrative examples are used in order to better understand the new features that the varying second Slow-Roll index introduces.

Ultra Slow-Roll Inflation and the non-Gaussianity Consistency Relation

It is demonstrated that the power spectrum remains scale-invariant and that the bi-spectrum is of the local type with fnl=5(3-ns)/4 which represents a modification of the consistency relation.

A Smooth Constant-Roll to a Slow-Roll Modular Inflation Transition

In this work, we investigate how a smooth transition from a constant-roll to a slow-roll inflationary era may be realized, in the context of a canonical scalar field theory. We study in some detail

Constant-roll inflation: Confrontation with recent observational data

The previously proposed class of phenomenological inflationary models in which the assumption of inflaton slow-roll is replaced by the more general, constant-roll condition is compared with the most

Horizon crossing and inflation with large η

I examine the standard formalism of calculating curvature perturbations in inflation at horizon crossing, and derive a general relation which must be satisfied for the horizon-crossing formalism to

f(R) constant-roll inflation

The previously introduced class of two-parametric phenomenological inflationary models in general relativity in which the slow-roll assumption is replaced by the more general, constant-roll condition

Ultra slow-roll G-inflation

The conventional slow-roll approximation is broken in the so-called "ultra slow-roll" models of inflation, for which the inflaton potential is exactly (or extremely) flat. The interesting nature of

Formalizing the slow-roll approximation in inflation.

This work proposes a new measure of inflation, based upon contraction of the comoving Hubble length as opposed to the usual $e$-foldings of physical expansion, and derives relevant formulae from an infinite hierarchy of slow-roll parameters.