One Small Step for an Inflaton, One Giant Leap for Inflation: a novel non-Gaussian tail and primordial black holes

Abstract

We report a novel prediction from single-field inflation that even a tiny step in the inflaton potential can change our perception of primordial non-Gaussianities of the curvature perturbation. Our analysis focuses on the tail of probability distribution generated by an upward step transition between two stages of slow-roll evolution. The nontrivial background dynamics with off-attractor behavior is identified. By using a non-perturbative $\delta N$ analysis, we explicitly show that a highly non-Gaussian tail can be generated by a tiny upward step, even when the conventional nonlinearity parameters $f_{NL}$, $g_{NL}$, etc. remain small. With this example, we demonstrate for the first time the sensitive dependence of non-perturbative effects on the tail of probability distribution. Our scenario has an inconceivable application to primordial black holes by either significantly boosting their abundance or completely forbidding their appearance.

arXiv comment7 pages, 4 figures

References in corpus (15)

• Planck 2018 results. X. Constraints on inflation
• Axion Cosmology
• A General Analytic Formula for the Spectral Index of the Density Perturbations produced during Inflation
• The inflationary prediction for primordial non-gaussianity
• Primordial Non-Gaussianities from Inflation Models
• Super-Horizon Scale Dynamics of Multi-Scalar Inflation
• Violation of non-Gaussianity consistency relation in a single field inflationary model
• Primordial Black Holes from Sound Speed Resonance during Inflation
• Primordial Black Holes and Local Non-Gaussianity in Canonical Inflation
• A Single Field Inflation Model with Large Local Non-Gaussianity
• Non-Gaussian tail of the curvature perturbation in stochastic ultra-slow-roll inflation: implications for primordial black hole production
• Dissecting the growth of the power spectrum for primordial black holes
• Primordial black holes and stochastic gravitational wave background from inflation with a noncanonical spectator field
• A Note on the Abundance of Primordial Black Holes: Use and Misuse of the Metric Curvature Perturbation
• Axion excursions of the landscape during inflation

Cited by in corpus (35)

• Anatomy of single-field inflationary models for primordial black holes
• Logarithmic Duality of the Curvature Perturbation
• PBH formation from spherically symmetric hydrodynamical perturbations: a review
• Primordial Black Holes
• Constraining Primordial Black Hole Formation from Single-Field Inflation
• Highly non-Gaussian tails and primordial black holes from single-field inflation
• Hybrid $\alpha$-attractors, primordial black holes and gravitational wave backgrounds
• Primordial black holes and gravitational waves induced by exponential-tailed perturbations
• Complete analysis of the background and anisotropies of scalar-induced gravitational waves: primordial non-Gaussianity $f_{\mathrm{NL}}$ and $g_{\mathrm{NL}}$ considered
• Missing one-loop contributions in secondary gravitational waves
• Highly asymmetric probability distribution from a finite-width upward step during inflation
• Quantum Diffusion in Sharp Transition to Non-Slow-Roll Phase
• Uphill inflation
• Multiple Field Ultra Slow Roll Inflation: Primordial Black Holes From Straight Bulk And Distorted Boundary
• Primordial black hole compaction function from stochastic fluctuations in ultra-slow-roll inflation
• Primordial black holes from Higgs inflation with a Gauss-Bonnet coupling
• Primordial black holes from an inflationary potential valley
• Smooth vs instant inflationary transitions: steepest growth re-examined and primordial black holes
• Constraints on ultra-slow-roll inflation from the third LIGO-Virgo observing run
• Sudden braking and turning with a two-field potential bump: primordial black hole formation
• Extended $\delta N$ formalism: Nonspatially Flat Separate Universe Approach
• Enhance Primordial Black Hole Abundance through the Non-linear Processes around Bounce Point
• Angular bispectrum and trispectrum of scalar-induced gravitational waves: all contributions from primordial non-Gaussianity $f_{\mathrm{NL}}$ and $g_{\mathrm{NL}}$
• Mechanisms for producing Primordial Black Holes from Inflationary Models Beyond Fine-Tuning
• Gravitational Waves From No-Scale Supergravity
• Constraints on Non-Gaussian primordial curvature perturbation from the LIGO-Virgo-KAGRA third observing run
• Detecting sublunar-mass primordial black holes with the Earth-Moon binary system
• Non-Gaussianities and Primordial Black Holes
• Generating large primordial fluctuations in single-field inflation for PBH formation
• Dip and non-linearity in the curvature perturbation from inflation with a transient non-slow-roll stage
• Primordial black holes save $R^2$ inflation
• Constraints on ultra-slow-roll inflation with the NANOGrav 15-Year Dataset
• Gravitational waves from primordial black hole dominance: The effect of inflaton decay rate
• Eternal inflation near inflection points: a challenge to primordial black hole models
• Effect of stochastic kicks on primordial black hole abundance and mass via the compaction function