A shear-free lattice method bridges stochastic inflation and δN formalism by enabling fully nonlinear calculations of curvature perturbations in single-field models with ultra-slow-roll phases.
Ultra Slow-Roll Inflation and the non-Gaussianity Consistency Relation
6 Pith papers cite this work. Polarity classification is still indexing.
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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UNVERDICTED 6representative citing papers
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.
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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Nonlinear Lattice Framework for Inflation: Bridging stochastic inflation and the $\delta{N}$ formalism
A shear-free lattice method bridges stochastic inflation and δN formalism by enabling fully nonlinear calculations of curvature perturbations in single-field models with ultra-slow-roll phases.
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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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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.