Systematics of Constant Roll Inflation

Abstract

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 $n_s\approx 1$. We investigate systematically the condition for such a constant-roll regime. In the process, we find a whole new class of inflationary models, in addition to the known solutions. We show that the new models are stable under scalar perturbations. Finally, we find a part of their parameter space, in which they produce a nearly scale-invariant scalar power spectrum, as needed for observational viability.

39 pages; minor corrections, references added

References in corpus (7)

• The Effective Field Theory of Inflation
• Ultra slow-roll inflation demystified
• Unification of Constant-roll Inflation and Dark Energy with Logarithmic $R^2$-corrected and Exponential $F(R)$ Gravity
• Reheating in Constant-roll $F(R)$ Gravity
• Minimal Composite Inflation
• A Smooth Constant-Roll to a Slow-Roll Modular Inflation Transition
• Large tensor-to-scalar ratio from Composite Inflation

Cited by in corpus (45)

• Inflation with Gauss-Bonnet coupling
• On the constant-roll inflation
• The attractive behaviour of ultra-slow-roll inflation
• Constant-Roll (Quasi-)Linear Inflation
• The Primordial Black Holes that Disappeared: Connections to Dark Matter and MHz-GHz Gravitational Waves
• Logarithmic-corrected $R^2$ Gravity Inflation in the Presence of Kalb-Ramond Fields
• Large-$\eta$ Constant-Roll Inflation Is Never An Attractor
• Constant-roll tachyon inflation and observational constraints
• Reviving non-Minimal Horndeski-like Theories after GW170817: Kinetic Coupling Corrected Einstein-Gauss-Bonnet Inflation
• Tachyon constant-roll inflation
• Constant-roll in the Palatini-$R^2$ models
• On Primordial Black Holes from Rapid Turns in Two-field Models
• Dynamical Analysis of Attractor Behavior in Constant Roll Inflation
• Brane Constant-roll Inflation
• Anisotropic constant-roll inflation with noncommutative model and swampland conjectures
• Constant-roll $k$-Inflation Dynamics
• Observational Constraints on Constant Roll Inflation
• Swampland Conjecture and Inflation Model from Brane Perspective
• Beta-function formalism for k-essence constant-roll inflation
• On the constant-roll inflation with large and small ${\eta }_H$
• Observational constraints on DBI constant-roll inflation
• Simple single-field inflation models with arbitrarily small tensor/scalar ratio
• Natural Inflation with non minimal coupling to gravity in $R^2$ gravity under the Palatini formalism
• Generalizing the Constant-roll Condition in Scalar Inflation
• Nonminimal coupling inflation with constant slow roll
• Constant roll warm inflation in high dissipative regime
• Constant-Roll Inflation in modified $f(R,\varphi )$ gravity model using Palatini Formalism
• Anisotropic constant-roll inflation for the Dirac-Born-Infeld model
• Hidden symmetries of two-field cosmological models
• The cosmic coincidences of primordial-black-hole dark matter
• Two-field constant roll inflation
• On the constant roll complex scalar field inflationary models
• Gauss-Bonnet inflation with a constant rate of roll
• Baryogenesis from ultra-slow-roll inflation
• End of the constant-roll inflation, and the reheating temperature
• Constant-roll Inflation in Brane Induced Gravity Cosmology
• Analytical Insights into Constant-Roll Condition: Extending the Paradigm to Non-Canonical Models
• Warm constant-roll inflation in brane-world cosmology
• Constant-roll inflation with non-minimally derivative coupling
• Constant-rate inflation: primordial black holes from conformal weight transitions
• Constant-roll inflation with tachyon field in the holographic braneworld
• $\delta N$ formalism with gradient interactions
• Constant-roll inflation and primordial black holes within Barrow entropic framework
• Tachyon constant-roll inflation in Randall-Sundrum II cosmology
• Anisotropic constant-roll k-inflation model