UV divergences of one-loop primordial tensor and scalar spectra are absorbed by covariant and tadpole counterterms using only the universal WKB expansion of internal modes, yielding finite model-independent renormalized expressions.
Mixed citations
Ultra Slow-Roll Inflation and the non-Gaussianity Consistency Relation
Mixed citation behavior. Most common role is background (60%).
abstract
Ultra slow-roll inflation has recently been used to challenge the non-Gaussianity consistency relation. We show that this inflationary scenario belongs to a one parameter class of models and we study its properties and observational predictions. We demonstrate that the power spectrum remains scale-invariant and that the bi-spectrum is of the local type with fnl=5(3-ns)/4 which, indeed, represents a modification of the consistency relation. However, we also show that the system is unstable and suffers from many physical problems among which is the difficulty to correctly WMAP normalize the model. We conclude that ultra slow-roll inflation remains a very peculiar case, the physical relevance of which is probably not sufficient to call into question the validity of the consistency relation.
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representative citing papers
Hybrid inflation's waterfall tachyonic instability grows isocurvature modes that convert to curvature perturbations at the field-space turn, yielding a k^{3}-peaked spectrum with always-positive f_NL that enhances PBH formation.
Analytical formulae for power spectrum peaks in constant-roll inflation enable parameter reconstruction from peak features and smoothed approximations for induced gravitational wave estimates.
The authors define a locality condition for hard-mode states during inflation that unifies local effective dynamics for soft modes, suppression of loop corrections, generalized soft theorems, and absence of infrared divergences in observable correlators.
Derives all-order Hamiltonians via EFT of inflation for USR models and shows L-loop corrections to CMB-scale perturbations scale as (ΔN P_e L)^L, exiting perturbative control at L=4 for typical ΔN≈2.5.
Tree-level multi-soft theorems for scalar and graviton correlation functions are derived at leading soft order via background-wave coordinate rescaling, including tensor exchanges in scalars and scalar exchanges in tensors.
A shear-free locally FLRW lattice framework for single-field inflation captures spatially varying expansion, curvature corrections, and nonlinear δN observables at a fraction of the cost of full numerical relativity.
One-loop time dependence in superhorizon curvature perturbations cancels when all-scale contributions and boundary terms are included consistently via the δN formalism.
Ward identities derived from perturbation-theory symmetries enforce non-perturbative constraints on the infrared power spectrum and guarantee conservation of super-horizon modes in non-attractor inflation.
Non-standard reheating imprints detectable features on SIGW spectra via non-Gaussianity, with dynamics that can suppress or boost the signal amplitude for LISA.
citing papers explorer
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Background-independent one-loop renormalization of tensor and scalar primordial spectra
UV divergences of one-loop primordial tensor and scalar spectra are absorbed by covariant and tadpole counterterms using only the universal WKB expansion of internal modes, yielding finite model-independent renormalized expressions.
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Superhorizon curvature perturbations in hybrid inflation revisited
Hybrid inflation's waterfall tachyonic instability grows isocurvature modes that convert to curvature perturbations at the field-space turn, yielding a k^{3}-peaked spectrum with always-positive f_NL that enhances PBH formation.
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Constant-Roll Inflation: Analytical Formulae for Power Spectrum and Implications for Induced Gravitational Waves
Analytical formulae for power spectrum peaks in constant-roll inflation enable parameter reconstruction from peak features and smoothed approximations for induced gravitational wave estimates.
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Locality in effective field theory for inflationary soft modes
The authors define a locality condition for hard-mode states during inflation that unifies local effective dynamics for soft modes, suppression of loop corrections, generalized soft theorems, and absence of infrared divergences in observable correlators.
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Hamiltonians to all Orders in Perturbation Theory and Higher Loop Corrections in Single Field Inflation with PBHs Formation
Derives all-order Hamiltonians via EFT of inflation for USR models and shows L-loop corrections to CMB-scale perturbations scale as (ΔN P_e L)^L, exiting perturbative control at L=4 for typical ΔN≈2.5.
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Multi-soft theorems for cosmological correlators: Background wave method for scalars & gravitons
Tree-level multi-soft theorems for scalar and graviton correlation functions are derived at leading soft order via background-wave coordinate rescaling, including tensor exchanges in scalars and scalar exchanges in tensors.
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Nonlinear Lattice Framework for Inflation: Bridging stochastic inflation and the $\delta{N}$ formalism
A shear-free locally FLRW lattice framework for single-field inflation captures spatially varying expansion, curvature corrections, and nonlinear δN observables at a fraction of the cost of full numerical relativity.
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Cancellation of one-loop time dependence in superhorizon curvature perturbations from all scales
One-loop time dependence in superhorizon curvature perturbations cancels when all-scale contributions and boundary terms are included consistently via the δN formalism.
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Ward Identity Constraints on Loop Corrections in Non-Attractor Inflation
Ward identities derived from perturbation-theory symmetries enforce non-perturbative constraints on the infrared power spectrum and guarantee conservation of super-horizon modes in non-attractor inflation.
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Probing non-Gaussianity during reheating with SIGW in the LISA band
Non-standard reheating imprints detectable features on SIGW spectra via non-Gaussianity, with dynamics that can suppress or boost the signal amplitude for LISA.