Inflation with a constant rate of roll

Abstract

We consider an inflationary scenario where the rate of inflaton roll defined by $\ddot{\varphi }/H\dot{\varphi }$ remains constant. The rate of roll is small for slow-roll inflation, while a generic rate of roll leads to the interesting case of `constant-roll' inflation. We find a general exact solution for the inflaton potential required for such inflaton behaviour. In this model, due to non-slow evolution of background, the would-be decaying mode of linear scalar (curvature) perturbations may not be neglected. It can even grow for some values of the model parameter, while the other mode always remains constant. However, this always occurs for unstable solutions which are not attractors for the given potential. The most interesting particular cases of constant-roll inflation remaining viable with the most recent observational data are quadratic hilltop inflation (with cutoff) and natural inflation (with an additional negative cosmological constant). In these cases even-order slow-roll parameters approach non-negligible constants while the odd ones are asymptotically vanishing in the quasi-de Sitter regime.

12 pages, 11 figures; v2. paper expanded, title changed; v3. three minor typos corrected

References in corpus (6)

• Single-field inflation, anomalous enhancement of superhorizon fluctuations, and non-Gaussianity in primordial black hole formation
• Whipped inflation
• Consistency relation for $R^p$ inflation
• Constraint on reheating after f(R) inflation from gravitational waves
• Tensor to scalar ratio and large scale power suppression from pre-slow roll initial conditions
• Stability of cosmological solutions in extended quasidilaton massive gravity

Cited by in corpus (168)

• Primordial Black Holes and Slow-Roll Violation
• The CosmoVerse White Paper: Addressing observational tensions in cosmology with systematics and fundamental physics
• Primordial Black Holes from $\alpha$-attractors
• Primordial black holes and second order gravitational waves from ultra-slow-roll inflation
• Primordial Black Holes from a tiny bump/dip in the Inflaton potential
• PBHs and secondary GWs from ultra slow roll and punctuated inflation
• Inflation and Primordial Black Holes
• Unification of Constant-roll Inflation and Dark Energy with Logarithmic $R^2$-corrected and Exponential $F(R)$ Gravity
• Primordial Black Holes from String Inflation
• Anatomy of single-field inflationary models for primordial black holes
• PBH in single field inflation: the effect of shape dispersion and non-Gaussianities
• Constant-roll Inflation in $f(T)$ Teleparallel Gravity
• $f(R)$ constant-roll inflation
• Planck scale black hole dark matter from Higgs inflation
• Constant-roll Inflation in $F(R)$ Gravity
• Constant-roll inflation: confrontation with recent observational data
• Inflation with Gauss-Bonnet coupling
• Inflation after Planck: Judgment Day
• Primordial black holes and secondary gravitational waves from inflationary model with a non-canonical kinetic term
• Constraining Primordial Black Hole Formation from Single-Field Inflation
• On the slope of curvature power spectrum in non-attractor inflation
• Stochastic Ultra Slow Roll Inflation
• An analytic approach to non-slow-roll inflation
• On the constant-roll inflation
• The attractive behaviour of ultra-slow-roll inflation
• Scalar induced gravitational waves in light of Pulsar Timing Array data
• Constant roll and primordial black holes
• Constant-Roll (Quasi-)Linear Inflation
• Squeezed bispectrum and one-loop corrections in transient constant-roll inflation
• Constraints on primordial curvature power spectrum with pulsar timing arrays
• Anisotropic Constant-roll Inflation
• Systematics of Constant Roll Inflation
• Failure of the stochastic approach to inflation beyond slow-roll
• Primordial black holes from modified supergravity
• The Primordial Black Holes that Disappeared: Connections to Dark Matter and MHz-GHz Gravitational Waves
• Inflation with a Smooth Constant-Roll to Constant-Roll Era Transition
• Logarithmic-corrected $R^2$ Gravity Inflation in the Presence of Kalb-Ramond Fields
• Inflationary Dynamics with a Smooth Slow-Roll to Constant-Roll Era Transition
• Primordial black holes and secondary gravitational waves from the Higgs field
• Large-$\eta$ Constant-Roll Inflation Is Never An Attractor
• Reheating in Constant-roll $F(R)$ Gravity
• Constant-roll inflation in scalar-tensor gravity
• New perspectives on constant-roll inflation
• Constant-roll tachyon inflation and observational constraints
• Features from the non-attractor beginning of inflation
• Stochastic constant-roll inflation and primordial black holes
• Constraints on primordial curvature spectrum from primordial black holes and scalar-induced gravitational waves
• Non-Gaussianity in inflationary scenarios for primordial black holes
• Reviving non-Minimal Horndeski-like Theories after GW170817: Kinetic Coupling Corrected Einstein-Gauss-Bonnet Inflation
• Model-independent reconstruction of the primordial curvature power spectrum from PTA data
• Primordial black holes and scalar-induced gravitational waves from the generalized Brans-Dicke theory
• Ultra slow-roll G-inflation
• Primordial black holes and secondary gravitational waves from chaotic inflation
• Numerical 1-loop correction from a potential yielding ultra-slow-roll dynamics
• Tachyon constant-roll inflation
• NANOGrav signal and LIGO-Virgo Primordial Black Holes from the Higgs field
• Constant-roll in the Palatini-$R^2$ models
• On Primordial Black Holes from Rapid Turns in Two-field Models
• A Nearly Massless Graviton in Einstein-Gauss-Bonnet Inflation with Linear Coupling Implies Constant-roll for the Scalar Field
• Disformal invariance of curvature perturbation
• Non-slow-roll dynamics in $\alpha -$attractors
• Dynamical Analysis of Attractor Behavior in Constant Roll Inflation
• Constant-roll approach to non-canonical inflation
• Reconstruction of constant slow-roll inflation
• Generalized Slow Roll in the Unified Effective Field Theory of Inflation
• Brane Constant-roll Inflation
• Squeezed tensor non-Gaussianity in non-attractor inflation
• Anisotropic constant-roll inflation with noncommutative model and swampland conjectures
• Constant-roll $k$-Inflation Dynamics
• Constant roll inflation in multifield models
• A new mechanism to enhance primordial tensor fluctuations in single field inflation
• Observational Constraints on Constant Roll Inflation
• One-loop infrared rescattering by enhanced scalar fluctuations during inflation
• The method of generating functions in exact scalar field cosmology
• The reconstruction of tachyon inflationary potentials
• Reconstruction of extended inflationary potentials for attractors
• Primordial black holes and induced gravitational waves from logarithmic non-Gaussianity
• Swampland Conjecture and Inflation Model from Brane Perspective
• Comparing sharp and smooth transitions of the second slow-roll parameter in single-field inflation
• Beta-function formalism for k-essence constant-roll inflation
• Absence of one-loop effects on large scales from small scales in non-slow-roll dynamics II: Quartic interactions and consistency relations
• Relaxing the TCC Bound on Inflationary Cosmology?
• Large Slow Roll Parameters in Single Field Inflation
• Are there really conformal frames? Uniqueness of affine inflation
• Constant-roll inflation in the generalized SU(2) Proca theory
• Stochastic non-attractor inflation
• On the constant-roll inflation with large and small ${\eta }_H$
• Observational constraints on DBI constant-roll inflation
• Cosmic evolution of the logarithmic f(R) model and the dS swampland conjecture
• A Smooth Constant-Roll to a Slow-Roll Modular Inflation Transition
• Why Must Primordial Non-Gaussianity Be Very Small?
• Brane inflation and Trans-Planckian censorship conjecture
• The observational constraint on constant-roll inflation
• Inflation with $0\le c_{\mathrm{s}}\le 1$
• Simple single-field inflation models with arbitrarily small tensor/scalar ratio
• Cosmological Perturbations and the Weinberg Theorem
• Dressed Power-law Inflation with Cuscuton
• Nonminimal coupling inflation with constant slow roll
• Natural Inflation with non minimal coupling to gravity in $R^2$ gravity under the Palatini formalism
• The primordial black hole from running curvaton
• Generalizing the Constant-roll Condition in Scalar Inflation
• Sudden braking and turning with a two-field potential bump: primordial black hole formation
• Absence of one-loop effects on large scales from small scales in non-slow-roll dynamics
• Constant roll warm inflation in high dissipative regime
• Constant-Roll Inflation in modified $f(R,\varphi )$ gravity model using Palatini Formalism
• Inflation and Bounce from Classical and Loop Quantum Cosmology Imperfect Fluids
• Boosting GWs in Supersolid Inflation
• Anisotropic constant-roll inflation for the Dirac-Born-Infeld model
• Gravitational waves in ultra-slow-roll and their anisotropy at two loops
• Hidden symmetries of two-field cosmological models
• $\alpha$-attractor from superconformal E-models in brane inflation
• Mutated hilltop inflation revisited
• Two-field constant roll inflation
• The cosmic coincidences of primordial-black-hole dark matter
• Constant roll and non-Gaussian tail in light of logarithmic duality
• The generalized $sl(2,R)$ and $su(1,1)$ in non-minimal constant-roll inflation
• Non-minimal coupling influence on the deviation from de Sitter cosmological expansion
• Intrinsic Entropy Perturbations from the Dark Sector
• Baryogenesis from ultra-slow-roll inflation
• On the constant roll complex scalar field inflationary models
• Parity violation in primordial tensor non-Gaussianities from matter bounce cosmology
• Superpotential method and the amplification of inflationary perturbations
• Global Portraits of Nonminimal Inflation: Metric and Palatini
• Fundamental Physics and Cosmology with TianQin
• Banks-Zaks Cosmology, Inflation, and the Big Bang Singularity
• Reconstruction methods and the amplification of the inflationary spectrum
• New one-parametric extension of the Starobinsky inflationary model
• Power-law Inflation Satisfies Penrose's Weyl Curvature Hypothesis
• Analytical Insights into Constant-Roll Condition: Extending the Paradigm to Non-Canonical Models
• Constant-roll Inflation in Brane Induced Gravity Cosmology
• Constant-roll, cosmic acceleration, and massive neutrinos
• Constant-roll inflation driven by a scalar field with non-minimal derivative coupling
• End of the constant-roll inflation, and the reheating temperature
• Adiabatic Media Inflation
• Potential-driven Inflation with Disformal Coupling to Gravity
• $\Delta N$ Formalism and Conserved Currents in Cosmology
• Non-Gaussianities and Primordial Black Holes
• Inflationary models that generalize the constant roll constraint
• Holographic inflation and holographic dark energy from entropy of the anti-de Sitter black hole
• Inflation as de Sitter instability
• Generating large primordial fluctuations in single-field inflation for PBH formation
• New method of exponential potentials reconstruction based on given scale factor in phantonical two-field models
• Reassessing constant-roll Warm Inflation
• The multi-measure cosmological model and its peculiar effective potential
• Natural inflation with natural number of e-foldings
• Cosmology from a running vacuum model driven by a scalar field
• Warm constant-roll inflation in brane-world cosmology
• Constant-roll warm inflation and the $\beta$-function approach
• On Non-slow Roll Inflationary Regimes
• Uniform Rate Inflation
• Notes on the post-bounce background dynamics in bouncing cosmologies
• Confronting Inflation Models with the Coming Observations on Primordial Gravitational Waves
• Primordial black holes and scalar-induced gravitational waves from the polynomial attractor model
• Constraints on Tensor to Scalar Ratio using WKB Approximation
• Glueball Inflation and Gauge/Gravity Duality
• The Trans-Planckian Censorship Conjecture in different frameworks of viable inflation
• Stochastic Inflation with Interacting Noises
• Constant-roll inflation with non-minimally derivative coupling
• Constant-roll inflation with tachyon field in the holographic braneworld
• Constant-rate inflation: primordial black holes from conformal weight transitions
• Dynamical Shortcomings in the Generalized SU(2) Proca Theory: Challenges for Cosmic Acceleration
• Eternal inflation near inflection points: a challenge to primordial black hole models
• $\delta N$ formalism with gradient interactions
• Tachyon constant-roll inflation in Randall-Sundrum II cosmology
• On solving dynamical equations in general homogeneous isotropic cosmologies with scalaron
• Constant-roll inflation and primordial black holes within Barrow entropic framework
• Anisotropic constant-roll k-inflation model
• How to obtain slow roll inflation driven by non-linear electrodynamics