Simple single-field inflation models with arbitrarily small tensor/scalar ratio

Abstract

We construct a family of simple single-field inflation models consistent with Planck / BICEP Keck bounds which have a parametrically small tensor amplitude and no running of the scalar spectral index. The construction consists of a constant-roll hilltop inflaton potential with the end of inflation left as a free parameter induced by higher-order operators which become dominant late in inflation. This construction directly demonstrates that there is no lower bound on the tensor/scalar ratio for simple single-field inflation models.

arXiv comment14 pages, 2 figures (V3: Version submitted to JCAP)

References in corpus (55)

• Planck 2015 results. XIII. Cosmological parameters
• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• Planck 2018 results. X. Constraints on inflation
• On the Geometry of the String Landscape and the Swampland
• BICEP / Keck XIII: Improved Constraints on Primordial Gravitational Waves using Planck, WMAP, and BICEP/Keck Observations through the 2018 Observing Season
• What would we learn by detecting a gravitational wave signal in the cosmic microwave background anisotropy?
• Planck 2015 results. XI. CMB power spectra, likelihoods, and robustness of parameters
• Cosmological parameters from combining the Lyman-alpha forest with CMB, galaxy clustering and SN constraints
• Horizon crossing and inflation with large η
• Ultra Slow-Roll Inflation and the non-Gaussianity Consistency Relation
• Violation of non-Gaussianity consistency relation in a single field inflationary model
• Inflation with a constant rate of roll
• Inflation after WMAP3: Confronting the Slow-Roll and Exact Power Spectra with CMB Data
• Inflation: flow, fixed points and observables to arbitrary order in slow roll
• Inflation model constraints from the Wilkinson Microwave Anisotropy Probe three-year data
• Cosmic microwave background measurements can discriminate among inflation models
• Ultra slow-roll inflation demystified
• Unification of Constant-roll Inflation and Dark Energy with Logarithmic $R^2$-corrected and Exponential $F(R)$ Gravity
• A Hamilton-Jacobi approach to non-slow-roll inflation
• Revisiting non-Gaussianity from non-attractor inflation models
• Constant-roll Inflation in $f(T)$ Teleparallel Gravity
• $f(R)$ constant-roll inflation
• Curvature perturbation at the local extremum of the inflaton's potential
• BICEP2 / Keck Array V: Measurements of B-mode Polarization at Degree Angular Scales and 150 GHz by the Keck Array
• Constant-roll Inflation in $F(R)$ Gravity
• Stochastic inflation in phase space: Is slow roll a stochastic attractor?
• Constraining Inflation with Cosmic Microwave Background Polarization
• On the constant-roll inflation
• Constant-Roll (Quasi-)Linear Inflation
• Consistently violating the non-Gaussian consistency relation
• A generalized non-Gaussian consistency relation for single field inflation
• Systematics of Constant Roll Inflation
• Inflation with a Smooth Constant-Roll to Constant-Roll Era Transition
• Inflation at Low Scales: General Analysis and a Detailed Model
• Inflation models after WMAP year three
• Inflationary Dynamics with a Smooth Slow-Roll to Constant-Roll Era Transition
• Large-$\eta$ Constant-Roll Inflation Is Never An Attractor
• New perspectives on constant-roll inflation
• Constant-roll tachyon inflation and observational constraints
• Features from the non-attractor beginning of inflation
• CMB targets after the latest Planck data release
• Initial Conditions for Critical Higgs Inflation
• Tachyon constant-roll inflation
• Eternal Hilltop Inflation
• Dynamical Analysis of Attractor Behavior in Constant Roll Inflation
• Constant-roll approach to non-canonical inflation
• Vanishing of local non-Gaussianity in canonical single field inflation
• Large Local Non-Gaussianity from General Single-field Inflation
• Effective Field Theory of non-Attractor Inflation
• A Smooth Constant-Roll to a Slow-Roll Modular Inflation Transition
• The observational constraint on constant-roll inflation
• Transients in finite inflation
• Running primordial perturbations: Inflationary Dynamics and Observational Constraints
• How to Produce an Arbitrarily Small Tensor to Scalar Ratio
• On Non-slow Roll Inflationary Regimes

Cited by in corpus (12)

• Inflationary interpretation of the stochastic gravitational wave background signal detected by pulsar timing array experiments
• Underdetermination of dark energy
• Squeezed bispectrum and one-loop corrections in transient constant-roll inflation
• Testing scale-invariant inflation against cosmological data
• Inflationary attractors and radiative corrections in light of ACT data
• Optimal Inflationary Potentials
• Minimizing the tensor-to-scalar ratio in single-field inflation models
• On the constant roll complex scalar field inflationary models
• A universal bound on the duration of a kination era
• Analytical Insights into Constant-Roll Condition: Extending the Paradigm to Non-Canonical Models
• Gravitational waves in a cyclic Universe: resilience through cycles and vacuum state
• Preheating and gravitational waves in large-field hilltop inflation