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arxiv: 2605.19331 · v1 · pith:TL3RHOBNnew · submitted 2026-05-19 · 🌀 gr-qc · astro-ph.CO· hep-th

Locality in effective field theory for inflationary soft modes

Pith reviewed 2026-05-20 05:16 UTC · model grok-4.3

classification 🌀 gr-qc astro-ph.COhep-th
keywords inflationary cosmologysoft modeseffective field theorygradient expansionsoft theoremsinfrared divergenceslocality conditionconsistency relations
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The pith

A locality condition on hard-mode states unifies the effective description of inflationary soft modes with soft theorems and IR regularity.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper establishes that a quantum state satisfies a locality condition when the hard-mode configuration inside each local patch depends on the soft modes only through the local values of those soft modes inside the same patch. When this holds, the coarse-grained dynamics of the soft modes stays local after integrating out shorter wavelengths. The same condition suppresses perturbative loop corrections from hard modes to superhorizon correlators of the curvature perturbation and guarantees infrared regularity for operators that are invariant under large gauge transformations. It also yields a generalized soft theorem from which the usual consistency relations follow once extra assumptions are added. A sympathetic reader cares because the condition supplies a model-independent test for when the gradient expansion and separate-universe picture remain reliable even in multi-field or non-attractor settings.

Core claim

When the hard-mode state in each local universe depends on the soft modes only through the local soft-mode values in the same patch, the coarse-grained soft-mode dynamics remains local, loop corrections from hard modes to superhorizon correlators of the adiabatic curvature perturbation are perturbatively suppressed, a generalized soft theorem holds, and correlators of operators invariant under a large gauge transformation remain free of infrared divergences. This supplies a unified criterion that diagnoses when enhanced hard-mode corrections can invalidate the gradient expansion and clarifies the origin of possible deviations from standard consistency relations.

What carries the argument

The locality condition that the hard-mode state inside each patch depends on soft modes solely through the local soft-mode values inside that patch.

If this is right

  • Coarse-grained soft-mode dynamics remains local after integrating out hard modes.
  • Perturbative loop corrections from hard modes to superhorizon correlators are suppressed.
  • A generalized soft theorem holds, from which standard consistency relations follow under additional assumptions.
  • Correlators of operators invariant under large gauge transformations are free of infrared divergences.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The criterion could be checked directly in lattice simulations by verifying whether subhorizon mode amplitudes depend only on the local superhorizon background inside each patch.
  • Models that violate the condition may produce observable departures from consistency relations without requiring new light degrees of freedom.
  • The same locality requirement might apply to soft-mode descriptions in other expanding cosmologies where a gradient expansion is used.

Load-bearing premise

A quantum state obeying the locality condition can be consistently defined and preserved by the inflationary dynamics.

What would settle it

An explicit construction or numerical simulation of an inflationary state in which the hard-mode configuration in a patch depends on non-local soft-mode information, followed by the appearance of unsuppressed hard-mode loop corrections or infrared divergences in gauge-invariant correlators, would falsify the central claim.

Figures

Figures reproduced from arXiv: 2605.19331 by Takahiro Tanaka, Yuko Urakawa.

Figure 1
Figure 1. Figure 1: Schematic illustration of the locality condition. After dividing the spatial slice into local patches [PITH_FULL_IMAGE:figures/full_fig_p005_1.png] view at source ↗
read the original abstract

The gradient expansion and the separate universe approach provide an effective description of inflationary soft modes after coarse-graining shorter-wavelength degrees of freedom. We formulate a locality condition on the quantum state, requiring that the hard-mode state in each local universe depend on the soft modes only through the local soft-mode values in the same patch. When this condition is satisfied, the coarse-grained soft-mode dynamics remains local, and loop corrections from hard modes to superhorizon correlators of the adiabatic curvature perturbation are perturbatively suppressed. This provides a model-independent diagnosis of when enhanced corrections due to hard modes can invalidate the gradient expansion. We further show that the same locality condition implies a generalized soft theorem, from which the standard consistency relations follow under additional assumptions. This formulation clarifies the origin of possible deviations from the standard consistency relations in multi-field systems or in a non-attractor background. We also show that the locality condition guarantees the absence of infrared divergences for the correlators of operators invariant under a large gauge transformation. Thus, locality of the hard-mode state provides a unified criterion for the effective description of inflationary soft modes, generalized soft theorems, the suppression of hard-mode loop corrections, and the infrared regularity of observable correlators.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 2 minor

Summary. The paper formulates a locality condition on the quantum state of hard modes in inflationary cosmology: the hard-mode state in each local patch depends on soft modes only through the local soft-mode values in that patch. When satisfied, this condition implies that coarse-grained soft-mode dynamics remains local, hard-mode loop corrections to superhorizon correlators of the adiabatic curvature perturbation are perturbatively suppressed, a generalized soft theorem holds (from which standard consistency relations follow under further assumptions), and correlators of operators invariant under large gauge transformations are free of infrared divergences. The locality condition is presented as a model-independent diagnostic for the validity of the gradient expansion and separate-universe approach, with implications for multi-field and non-attractor backgrounds.

Significance. If the locality condition can be consistently defined and preserved under inflationary dynamics, the work supplies a unified criterion linking the effective description of soft modes, suppression of hard-mode corrections, generalized soft theorems, and IR regularity. This could clarify the origin of deviations from standard consistency relations and provide a diagnostic for when enhanced hard-mode effects invalidate the gradient expansion. The approach is grounded in the separate-universe and gradient-expansion frameworks standard in the field.

major comments (2)
  1. [Abstract and introduction] The central claim requires that the locality condition be preserved under the unitary time evolution generated by the inflationary Hamiltonian (or under decoherence). The abstract states implications hold 'when this condition is satisfied' but does not appear to contain an explicit derivation or check that the full dynamics maintains the locality property rather than inducing non-local dependence across patches. This is load-bearing for all listed consequences.
  2. [Section on generalized soft theorems] § on generalized soft theorem: the derivation that the locality condition implies the generalized soft theorem (and that standard consistency relations follow under additional assumptions) needs explicit verification against a concrete multi-field or non-attractor example where deviations are known to occur, to confirm the condition is the precise origin of such deviations.
minor comments (2)
  1. [Formulation of locality condition] Clarify the precise mathematical statement of the locality condition (e.g., whether it is formulated in terms of the wavefunctional or density matrix) and its relation to the coarse-graining procedure.
  2. [Introduction] Add a brief discussion of how the condition relates to existing literature on separate-universe approaches and soft theorems (e.g., references to Maldacena, Creminelli et al.).

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for their careful reading of our manuscript and for the constructive comments. We address the major comments point by point below, indicating the revisions we plan to make.

read point-by-point responses
  1. Referee: [Abstract and introduction] The central claim requires that the locality condition be preserved under the unitary time evolution generated by the inflationary Hamiltonian (or under decoherence). The abstract states implications hold 'when this condition is satisfied' but does not appear to contain an explicit derivation or check that the full dynamics maintains the locality property rather than inducing non-local dependence across patches. This is load-bearing for all listed consequences.

    Authors: We agree that the preservation of the locality condition under the dynamics is a key point. The manuscript defines the condition on the state and derives the consequences assuming it holds at the relevant time. We do not claim that the condition is automatically preserved by the full unitary evolution; rather, it serves as a criterion for the validity of the effective description. In the revised version, we will expand the discussion in the introduction and add a new paragraph explaining how the condition can be preserved under evolution in the inflationary context, particularly when hard modes decouple and decoherence occurs locally. This addresses the load-bearing aspect by clarifying the regime of applicability. revision: yes

  2. Referee: [Section on generalized soft theorems] § on generalized soft theorem: the derivation that the locality condition implies the generalized soft theorem (and that standard consistency relations follow under additional assumptions) needs explicit verification against a concrete multi-field or non-attractor example where deviations are known to occur, to confirm the condition is the precise origin of such deviations.

    Authors: The derivation of the generalized soft theorem is presented as a direct consequence of the locality condition in the dedicated section, without relying on specific model details. It shows how the condition leads to the soft theorem, with standard relations emerging under further assumptions such as attractor behavior. While we do not include a full numerical verification in a specific multi-field model in the current manuscript, the general argument identifies the breakdown of locality as the source of deviations, aligning with known results in the literature for such backgrounds. To strengthen this, we will add in the revision a short discussion referencing a concrete example from the literature (e.g., a multi-field model with known consistency relation violations) and explain how locality is violated there. This provides the requested verification without requiring new computations. revision: partial

Circularity Check

0 steps flagged

No significant circularity: locality condition posited independently with self-contained derivations

full rationale

The paper introduces the locality condition on the quantum state as an explicit premise ('We formulate a locality condition on the quantum state, requiring that the hard-mode state in each local universe depend on the soft modes only through the local soft-mode values in the same patch'). From this assumption it derives the listed consequences for coarse-grained dynamics, loop suppression, generalized soft theorems, and IR regularity. No quoted step reduces any prediction or result to the input by construction, renames a known pattern, or loads the central claim on a self-citation chain whose verification is internal to the present work. The derivation therefore remains logically independent of its starting assumption and does not exhibit any of the enumerated circularity patterns.

Axiom & Free-Parameter Ledger

0 free parameters · 2 axioms · 0 invented entities

Based on the abstract alone, the central claims rest on standard domain assumptions of inflationary effective field theory and the separate-universe picture; no explicit free parameters or new invented entities are mentioned.

axioms (2)
  • domain assumption The gradient expansion and separate-universe approach provide a valid effective description of inflationary soft modes after coarse-graining.
    Invoked at the opening of the abstract as the starting point for the effective description.
  • domain assumption Hard-mode states can be defined locally in patches whose size is set by the soft-mode wavelength.
    Implicit in the formulation of the locality condition on the quantum state.

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Works this paper leans on

75 extracted references · 75 canonical work pages · 43 internal anchors

  1. [1]

    E. M. Lifshitz and I. M. Khalatnikov. Investigations in relativistic cosmology. Sov. Phys. Usp., 6:495–522, 1964. [Usp. Fiz. Nauk 80, 391 (1963)].doi:10.1070/PU1964v006n04ABEH003585

  2. [2]

    Starobinsky

    Alexei A. Starobinsky. Dynamics of Phase Transition in the New Inflationary Universe Scenario and Generation of Perturbations. Phys. Lett., 117B:175–178, 1982.doi:10.1016/0370-2693(82)90541-X

  3. [3]

    Long wavelength iteration of Einstein's equations near a spacetime singularity

    Nathalie Deruelle and David Langlois. Long wavelength iteration of Einstein’s equations near a space-time singularity. Phys. Rev., D52:2007–2019, 1995.arXiv:gr-qc/9411040,doi:10.1103/PhysRevD.52.2007

  4. [4]

    D. S. Salopek and J. R. Bond. Nonlinear evolution of long wavelength metric fluctuations in inflationary models. Phys. Rev., D42:3936–3962, 1990.doi:10.1103/PhysRevD.42.3936

  5. [5]

    Misao Sasaki and Ewan D. Stewart. A General analytic formula for the spectral index of the density perturbations produced during inflation. Prog. Theor. Phys., 95:71–78, 1996.arXiv:astro-ph/9507001,doi:10.1143/PTP.95.71

  6. [6]

    A new approach to the evolution of cosmological perturbations on large scales

    David Wands, Karim A. Malik, David H. Lyth, and Andrew R. Liddle. A New approach to the evolution of cosmological perturbations on large scales. Phys. Rev., D62:043527, 2000.arXiv:astro-ph/0003278,doi:10.1103/PhysRevD.62. 043527

  7. [7]

    A general proof of the conservation of the curvature perturbation

    David H. Lyth, Karim A. Malik, and Misao Sasaki. A General proof of the conservation of the curvature perturbation. JCAP, 0505:004, 2005.arXiv:astro-ph/0411220,doi:10.1088/1475-7516/2005/05/004

  8. [8]

    Starobinsky

    Alexei A. Starobinsky. Multicomponent de Sitter (Inflationary) Stages and the Generation of Perturbations. JETP Lett., 42:152–155, 1985. [Pisma Zh. Eksp. Teor. Fiz.42,124(1985)]

  9. [9]

    Super-Horizon Scale Dynamics of Multi-Scalar Inflation

    Misao Sasaki and Takahiro Tanaka. Superhorizon scale dynamics of multiscalar inflation. Prog. Theor. Phys., 99:763–782, 1998.arXiv:gr-qc/9801017,doi:10.1143/PTP.99.763

  10. [10]

    Nonlinear Lattice Framework for Inflation: Bridging stochastic inflation and the $\delta{N}$ formalism

    Pankaj Saha, Yuichiro Tada, and Yuko Urakawa. Nonlinear Lattice Framework for Inflation: Bridging stochastic inflation and theδNformalism. 4 2026.arXiv:2604.00978

  11. [11]

    Anisotropic separate universe and Weinberg’s adiabatic mode

    Takahiro Tanaka and Yuko Urakawa. Anisotropic separate universe and Weinberg’s adiabatic mode. JCAP, 07:051, 2021. arXiv:2101.05707,doi:10.1088/1475-7516/2021/07/051

  12. [12]

    Statistical Anisotropy of Primordial Gravitational Waves from GeneralizedδN Formalism

    Takahiro Tanaka and Yuko Urakawa. Statistical Anisotropy of Primordial Gravitational Waves from GeneralizedδN Formalism. Phys. Rev. Lett., 132(23):231003, 2024.arXiv:2309.08497,doi:10.1103/PhysRevLett.132.231003

  13. [13]

    Konoplya, J

    Takahiro Tanaka and Yuko Urakawa. gδN formalism. JCAP, 07:045, 2025.arXiv:2408.13673,doi:10.1088/1475-7516/ 2025/07/045

  14. [14]

    Constraining Primordial Black Hole Formation from Single-Field Inflation

    Jason Kristiano and Jun’ichi Yokoyama. Constraining Primordial Black Hole Formation from Single-Field Inflation. Phys. Rev. Lett., 132(22):221003, 2024.arXiv:2211.03395,doi:10.1103/PhysRevLett.132.221003

  15. [15]

    Benbrik, M

    Jason Kristiano and Jun’ichi Yokoyama. Note on the bispectrum and one-loop corrections in single-field inflation with primordial black hole formation. Phys. Rev. D, 109(10):103541, 2024.arXiv:2303.00341,doi:10.1103/PhysRevD.109. 103541

  16. [16]

    One-loop tensor power spectrum from an excited scalar field during inflation

    Atsuhisa Ota, Misao Sasaki, and Yi Wang. One-loop tensor power spectrum from an excited scalar field during inflation. Phys. Rev. D, 108(4):043542, 2023.arXiv:2211.12766,doi:10.1103/PhysRevD.108.043542

  17. [17]

    Primordial Black Holes and Loops in Single-Field Inflation

    Hassan Firouzjahi and Antonio Riotto. Primordial Black Holes and Loops in Single-Field Inflation. JCAP, 02:021, 2024. arXiv:2304.07801,doi:10.1088/1475-7516/2024/02/021

  18. [18]

    Proving the absence of large one-loop corrections to the power spectrum of curvature perturbations in transient ultra-slow-roll inflation within the path-integral approach

    Ryodai Kawaguchi, Shinji Tsujikawa, and Yusuke Yamada. Proving the absence of large one-loop corrections to the power spectrum of curvature perturbations in transient ultra-slow-roll inflation within the path-integral approach. JHEP, 12:095, 2024.arXiv:2407.19742,doi:10.1007/JHEP12(2024)095

  19. [19]

    Absence of one-loop effects on large scales from small scales in non-slow-roll dynamics II: Quartic interactions and consistency relations

    Jacopo Fumagalli. Absence of one-loop effects on large scales from small scales in non-slow-roll dynamics II: Quartic interactions and consistency relations. JHEP, 01:108, 2025.arXiv:2408.08296,doi:10.1007/JHEP01(2025)108

  20. [20]

    Tsamis and R.P

    N.C. Tsamis and R.P. Woodard. The Physical basis for infrared divergences in inflationary quantum gravity. Class. Quant. Grav., 11:2969–2990, 1994.doi:10.1088/0264-9381/11/12/012

  21. [21]

    N. C. Tsamis and R. P. Woodard. Quantum gravity slows inflation. Nucl. Phys. B, 474:235–248, 1996.arXiv:hep-ph/ 9602315,doi:10.1016/0550-3213(96)00246-5

  22. [22]

    Infrared effects in inflationary correlation functions

    David Seery. Infrared effects in inflationary correlation functions. Class. Quant. Grav., 27:124005, 2010.arXiv:1005.1649, doi:10.1088/0264-9381/27/12/124005

  23. [23]

    Influence on observation from IR divergence during inflation -- Single field inflation --

    Yuko Urakawa and Takahiro Tanaka. Influence on Observation from IR Divergence during Inflation. I.Prog. Theor. Phys., 122:779–803, 2009.arXiv:0902.3209,doi:10.1143/PTP.122.779

  24. [24]

    Influence on observation from IR divergence during inflation -- Multi field inflation --

    Yuko Urakawa and Takahiro Tanaka. Influence on observation from IR divergence during inflation: Multi field inflation. Prog. Theor. Phys., 122:1207–1238, 2010.arXiv:0904.4415,doi:10.1143/PTP.122.1207

  25. [25]

    IR divergence does not affect the gauge-invariant curvature perturbation

    Yuko Urakawa and Takahiro Tanaka. IR divergence does not affect the gauge-invariant curvature perturbation.Phys. Rev. D, 82:121301, 2010.arXiv:1007.0468,doi:10.1103/PhysRevD.82.121301

  26. [26]

    Natural selection of inflationary vacuum required by infra-red regularity and gauge-invariance

    Yuko Urakawa and Takahiro Tanaka. Natural selection of inflationary vacuum required by infra-red regularity and gauge- invariance. Prog. Theor. Phys., 125:1067–1089, 2011.arXiv:1009.2947,doi:10.1143/PTP.125.1067

  27. [27]

    Strong restriction on inflationary vacua from the local gauge invariance II: Infrared regularity and absence of the secular growth in Euclidean vacuum

    Takahiro Tanaka and Yuko Urakawa. Strong restriction on inflationary vacua from the local gauge invariance II: Infrared 18 regularity and absence of secular growth in the Euclidean vacuum. PTEP, 2013(6):063E02, 2013.arXiv:1301.3088, doi:10.1093/ptep/ptt037

  28. [28]

    Large gauge transformation, Soft theorem, and Infrared divergence in inflationary spacetime

    Takahiro Tanaka and Yuko Urakawa. Large gauge transformation, Soft theorem, and Infrared divergence in inflationary spacetime. JHEP, 10:127, 2017.arXiv:1707.05485,doi:10.1007/JHEP10(2017)127

  29. [29]

    Inflationary Correlation Functions without Infrared Divergences

    Mischa Gerstenlauer, Arthur Hebecker, and Gianmassimo Tasinato. Inflationary Correlation Functions without Infrared Divergences. JCAP, 06:021, 2011.arXiv:1102.0560,doi:10.1088/1475-7516/2011/06/021

  30. [30]

    On Loops in Inflation II: IR Effects in Single Clock Inflation

    Leonardo Senatore and Matias Zaldarriaga. On Loops in Inflation II: IR Effects in Single Clock Inflation. JHEP, 01:109, 2013.arXiv:1203.6354,doi:10.1007/JHEP01(2013)109

  31. [31]

    Semiclassical relations and IR effects in de Sitter and slow-roll space-times

    Steven B. Giddings and Martin S. Sloth. Semiclassical relations and IR effects in de Sitter and slow-roll space-times. JCAP, 01:023, 2011.arXiv:1005.1056,doi:10.1088/1475-7516/2011/01/023

  32. [32]

    Cosmological observables, IR growth of fluctuations, and scale-dependent anisotropies

    Steven B. Giddings and Martin S. Sloth. Cosmological observables, IR growth of fluctuations, and scale-dependent anisotropies. Phys. Rev. D, 84:063528, 2011.arXiv:1104.0002,doi:10.1103/PhysRevD.84.063528

  33. [33]

    Loops in inflationary correlation functions

    Takahiro Tanaka and Yuko Urakawa. Loops in inflationary correlation functions. Class. Quant. Grav., 30:233001, 2013. arXiv:1306.4461,doi:10.1088/0264-9381/30/23/233001

  34. [34]

    Adiabatic Modes in Cosmology

    Steven Weinberg. Adiabatic modes in cosmology. Phys. Rev., D67:123504, 2003.arXiv:astro-ph/0302326,doi:10.1103/ PhysRevD.67.123504

  35. [35]

    Conformal Symmetries of Adiabatic Modes in Cosmology

    Kurt Hinterbichler, Lam Hui, and Justin Khoury. An Infinite Set of Ward Identities for Adiabatic Modes in Cosmology. JCAP, 01:039, 2014.arXiv:1203.6351,doi:10.1088/1475-7516/2014/01/039

  36. [36]

    Systematics of Adiabatic Modes: Flat Universes

    Sadra Jazayeri and Enrico Pajer. Systematics of Adiabatic Modes: Flat Universes. JCAP, 04:019, 2018.arXiv:1710.02177, doi:10.1088/1475-7516/2018/04/019

  37. [37]

    Large gauge transformations, local coordinates and cosmological observables

    Ermis Mitsou, Enrico Pajer, and Drian van der Woude. Large gauge transformations, local coordinates and cosmological observables. Phys. Lett. B, 834:137418, 2022.arXiv:2109.13154,doi:10.1016/j.physletb.2022.137418

  38. [38]

    Conservation of $\zeta$ with radiative corrections from heavy field

    Takahiro Tanaka and Yuko Urakawa. Conservation ofζwith radiative corrections from heavy field. JCAP, 1606(06):020, 2016.arXiv:1510.05059,doi:10.1088/1475-7516/2016/06/020

  39. [39]

    Quantum contributions to cosmological correlations

    Steven Weinberg. Quantum contributions to cosmological correlations. Phys. Rev. D, 72:043514, 2005.arXiv:hep-th/ 0506236,doi:10.1103/PhysRevD.72.043514

  40. [40]

    Dominance of gauge artifact in the consistency relation for the primordial bispectrum

    Takahiro Tanaka and Yuko Urakawa. Dominance of gauge artifact in the consistency relation for the primordial bispectrum. JCAP, 05:014, 2011.arXiv:1103.1251,doi:10.1088/1475-7516/2011/05/014

  41. [41]

    Strong restriction on inflationary vacua from the local gauge invariance III: Infrared regularity of graviton loops

    Takahiro Tanaka and Yuko Urakawa. Strong restriction on inflationary vacua from the localgaugeinvariance III: Infrared regularity of graviton loops. PTEP, 2014(7):073E01, 2014.arXiv:1402.2076,doi:10.1093/ptep/ptu071

  42. [42]

    Single field consistency relation for the 3-point function

    Paolo Creminelli and Matias Zaldarriaga. Single field consistency relation for the 3-point function. JCAP, 10:006, 2004. arXiv:astro-ph/0407059,doi:10.1088/1475-7516/2004/10/006

  43. [43]

    One-particle-irreducible consistency relations for cosmological perturbations

    Walter D. Goldberger, Lam Hui, and Alberto Nicolis. One-particle-irreducible consistency relations for cosmological perturbations. Phys. Rev. D, 87(10):103520, 2013.arXiv:1303.1193,doi:10.1103/PhysRevD.87.103520

  44. [44]

    Inflationary Consistency Conditions from a Wavefunctional Perspective

    Guilherme L. Pimentel. Inflationary Consistency Conditions from a Wavefunctional Perspective. JHEP, 02:124, 2014. arXiv:1309.1793,doi:10.1007/JHEP02(2014)124

  45. [45]

    Consistency relations and conservation of $\zeta$ in holographic inflation

    Jaume Garriga and Yuko Urakawa. Consistency relations and conservation ofζin holographic inflation. JCAP, 10:030, 2016.arXiv:1606.04767,doi:10.1088/1475-7516/2016/10/030

  46. [46]

    Lam Hui, Austin Joyce, and Sam S. C. Wong. Inflationary soft theorems revisited: A generalized consistency relation. JCAP, 1902:060, 2019.arXiv:1811.05951,doi:10.1088/1475-7516/2019/02/060

  47. [47]

    Non-Gaussian features of primordial fluctuations in single field inflationary models

    Juan Martin Maldacena. Non-Gaussian features of primordial fluctuations in single field inflationary models. JHEP, 05:013, 2003.arXiv:astro-ph/0210603,doi:10.1088/1126-6708/2003/05/013

  48. [48]

    On Loops in Inflation III: Time Independence of zeta in Single Clock Inflation

    Guilherme L. Pimentel, Leonardo Senatore, and Matias Zaldarriaga. On Loops in Inflation III: Time Independence of zeta in Single Clock Inflation. JHEP, 07:166, 2012.arXiv:1203.6651,doi:10.1007/JHEP07(2012)166

  49. [49]

    William H. Kinney. Horizon crossing and inflation with large eta. Phys. Rev., D72:023515, 2005.arXiv:gr-qc/0503017, doi:10.1103/PhysRevD.72.023515

  50. [50]

    Violation of non-Gaussianity consistency relation in a single field inflationary model

    Mohammad Hossein Namjoo, Hassan Firouzjahi, and Misao Sasaki. Violation of non-Gaussianity consistency relation in a single field inflationary model. EPL, 101(3):39001, 2013.arXiv:1210.3692,doi:10.1209/0295-5075/101/39001

  51. [51]

    Ultra Slow-Roll Inflation and the non-Gaussianity Consistency Relation

    Jerome Martin, Hayato Motohashi, and Teruaki Suyama. Ultra Slow-Roll Inflation and the non-Gaussianity Consistency Relation. Phys. Rev. D, 87(2):023514, 2013.arXiv:1211.0083,doi:10.1103/PhysRevD.87.023514

  52. [52]

    A Single Field Inflation Model with Large Local Non-Gaussianity

    Xingang Chen, Hassan Firouzjahi, Mohammad Hossein Namjoo, and Misao Sasaki. A Single Field Inflation Model with Large Local Non-Gaussianity. EPL, 102(5):59001, 2013.arXiv:1301.5699,doi:10.1209/0295-5075/102/59001

  53. [53]

    In-in and $\delta N$ calculations of the bispectrum from non-attractor single-field inflation

    Xingang Chen, Hassan Firouzjahi, Eiichiro Komatsu, Mohammad Hossein Namjoo, and Misao Sasaki. In-in andδN calculations of the bispectrum from non-attractor single-field inflation. JCAP, 12:039, 2013.arXiv:1308.5341,doi: 10.1088/1475-7516/2013/12/039

  54. [54]

    Revisiting non-Gaussianity in non-attractor inflation models in the light of the cosmological soft theorem

    Teruaki Suyama. Revisiting non-Gaussianity in non-attractor inflation models in the light of the cosmological soft theorem. PTEP, 2021(7):073E02, 2021.arXiv:2101.10682,doi:10.1093/ptep/ptab064

  55. [55]

    Bassett, and Roy Maartens

    Christopher Gordon, David Wands, Bruce A. Bassett, and Roy Maartens. Adiabatic and entropy perturbations from inflation. Phys. Rev. D, 63:023506, Dec 2000. URL:https://link.aps.org/doi/10.1103/PhysRevD.63.023506,doi: 10.1103/PhysRevD.63.023506

  56. [56]

    Enhancement of superhorizon scale inflationary curvature perturbations

    Samuel M Leach, Misao Sasaki, David Wands, and Andrew R Liddle. Enhancement of superhorizon scale inflationary curvature perturbations. Phys. Rev., D64:023512, 2001.arXiv:astro-ph/0101406,doi:10.1103/PhysRevD.64.023512

  57. [57]

    Superhorizon Curvature Perturbations Are Protected against One-Loop Corrections

    Keisuke Inomata. Superhorizon Curvature Perturbations Are Protected against One-Loop Corrections. Phys. Rev. Lett., 133(14):141001, 2024.arXiv:2403.04682,doi:10.1103/PhysRevLett.133.141001. 19

  58. [58]

    Cancellation of loop corrections to soft scalar power spectrum

    Yohei Ema, Muzi Hong, Ryusuke Jinno, and Kyohei Mukaida. Cancellation of loop corrections to soft scalar power spectrum. 2026.arXiv:2603.01961

  59. [59]

    Starobinsky

    Alexei A. Starobinsky. STOCHASTIC DE SITTER (INFLATIONARY) STAGE IN THE EARLY UNIVERSE. Lect. Notes Phys., 246:107–126, 1986.doi:10.1007/3-540-16452-9_6

  60. [60]

    Equilibrium State of a Massless Self-Interacting Scalar Field in the De Sitter Background

    Alexei A. Starobinsky and Junichi Yokoyama. Equilibrium state of a selfinteracting scalar field in the De Sitter background. Phys. Rev., D50:6357–6368, 1994.arXiv:astro-ph/9407016,doi:10.1103/PhysRevD.50.6357

  61. [61]

    Soft de Sitter Effective Theory

    Timothy Cohen and Daniel Green. Soft de Sitter Effective Theory. JHEP, 12:041, 2020.arXiv:2007.03693,doi: 10.1007/JHEP12(2020)041

  62. [62]

    Cohen, D

    Timothy Cohen and Daniel Green. Stochastic Inflation at NNLO. JHEP, 12:036, 2021.arXiv:2106.09728,doi:10.1007/ JHEP12(2021)036

  63. [63]

    Soft Metric Fluctuations During Inflation

    Daniel Green and Kshitij Gupta. Soft Metric Fluctuations During Inflation. Phys. Rev. D, 112(4):043526, 2025.arXiv: 2410.11973,doi:10.1103/9ywk-xccj

  64. [64]

    Strong restriction on inflationary vacua from the local gauge invariance I: Local gauge invariance and infrared regularity

    Takahiro Tanaka and Yuko Urakawa. Strong restriction on inflationary vacua from the local gauge invariance I: Local gauge invariance and infrared regularity. PTEP, 2013:083E01, 2013.arXiv:1209.1914,doi:10.1093/ptep/ptt057

  65. [65]

    Note on the Radiation Field of the Electron

    Felix Bloch and Arnold Nordsieck. Note on the Radiation Field of the Electron. Phys. Rev., 52:54–59, 1937.doi: 10.1103/PhysRev.52.54

  66. [66]

    Infrared Photons and Gravitons

    Steven Weinberg. Infrared Photons and Gravitons. Phys. Rev., 140:B516–B524, 1965.doi:10.1103/PhysRev.140.B516

  67. [67]

    Mass singularities of Feynman amplitudes

    Toichiro Kinoshita. Mass singularities of Feynman amplitudes. J. Math. Phys., 3:650–677, 1962.doi:10.1063/1.1724268

  68. [68]

    T. D. Lee and M. Nauenberg. Degenerate Systems and Mass Singularities. Phys. Rev., 133:B1549–B1562, 1964.doi: 10.1103/PhysRev.133.B1549

  69. [69]

    V. Chung. Infrared Divergence in Quantum Electrodynamics. Phys. Rev., 140:B1110–B1122, 1965.doi:10.1103/PhysRev. 140.B1110

  70. [70]

    L. D. Faddeev and P. P. Kulish. Asymptotic conditions and infrared divergences in quantum electrodynamics. Theor. Math. Phys., 4:745–757, 1970. [Teor. Mat. Fiz. 4, 153 (1970)].doi:10.1007/BF01066485

  71. [71]

    Asymptotic Symmetries of Yang-Mills Theory

    Andrew Strominger. Asymptotic Symmetries of Yang-Mills Theory. JHEP, 07:151, 2014.arXiv:1308.0589,doi:10.1007/ JHEP07(2014)151

  72. [72]

    New Symmetries of Massless QED

    Temple He, Prahar Mitra, Achilleas P. Porfyriadis, and Andrew Strominger. New Symmetries of Massless QED. JHEP, 10:112, 2014.arXiv:1407.3789,doi:10.1007/JHEP10(2014)112

  73. [73]

    Lectures on the Infrared Structure of Gravity and Gauge Theory

    Andrew Strominger. Lectures on the Infrared Structure of Gravity and Gauge Theory. Princeton University Press, 2018. arXiv:1703.05448

  74. [74]

    Infrared Divergences in QED, Revisited

    Daniel Kapec, Malcolm Perry, Ana-Maria Raclariu, and Andrew Strominger. Infrared Divergences in QED, Revisited. Phys. Rev. D, 96(8):085002, 2017.arXiv:1705.04311,doi:10.1103/PhysRevD.96.085002

  75. [75]

    in progress

    Tadashi Kuramoto, Takahiro Tanaka, and Yuko Urakawa. in progress