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T0 review · glm-5.2

Quantum Environment Reshapes Inflation's Gravitational Wave Signal

2026-07-09 05:18 UTC pith:TLBN3KOD

load-bearing objection Real new result: first computation of P_ζ and SIGW from an open quantum system in USR. The headline LISA claims rest on a strong-coupling regime (λ/H=5) where the Gaussian truncation may not be self-consistent. the 2 major comments →

arxiv 2607.07602 v1 pith:TLBN3KOD submitted 2026-07-08 astro-ph.CO gr-qchep-th

When the Environment Speaks: Quantum Signatures in Non-Attractor Inflation

classification astro-ph.CO gr-qchep-th
keywords environmentquantumbackgroundduringimprintinflationprimordialscalar
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved

The pith

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

This paper argues that when the curvature perturbation driving inflation is treated as an open quantum system—coupled to a massive hidden 'entropic' field that acts as an environment—the quantum-to-classical transition (decoherence) is not a passive backdrop but leaves distinct, calculable fingerprints on the primordial power spectrum and on the stochastic gravitational wave background it produces. The authors study a specific inflationary scenario featuring a transient Ultra-Slow-Roll (USR) phase sandwiched between standard Slow-Roll (SR) phases, which is the standard mechanism for amplifying primordial fluctuations to levels relevant for primordial black hole formation. They use a Gaussian two-field effective Lagrangian where the adiabatic curvature perturbation (the system) couples bilinearly to a massive entropic scalar (the environment), and they evolve the full quantum state exactly using the Transport Equations Method, which tracks the covariance matrix of the system without perturbative or Markovian approximations, across the sharp SR-USR-SR transitions using the exact background kinematics. The central discovery is a chain of causal links: the USR phase acts as an engine of violent, irreversible decoherence for modes crossing the horizon during it; the efficiency of this decoherence depends sharply on the environmental mass relative to the Hubble scale, with m/H ≈ 1 producing the fastest loss of quantum coherence; and this rapid decoherence directly erases the destructive interference dip that normally precedes the power spectrum enhancement in single-field USR models, because the environment randomizes the relative phase between the mode function's growing and decaying branches before the interference pattern can form. Under strong coupling (λ/H = 5), additional features appear: suppressed peak amplitudes and oscillatory ringing near the peak. Because the scalar-induced gravitational wave background depends quadratically on the power spectrum, all these distortions propagate into the GW signal—altering its infrared slope, suppressing its peak, shifting it to higher frequencies, and inducing resonant modulations in its tail. These deviations break the degeneracy of single-field USR predictions and fall within the LISA sensitivity band, suggesting that future gravitational wave observations could directly constrain the quantum properties of the inflé

Core claim

The paper establishes that when an entropic environment with mass near the Hubble scale (m/H ≈ 1) interacts with curvature perturbations during a transient USR phase, the resulting rapid decoherence erases the characteristic interference dip in the primordial power spectrum—a feature that is robust in single-field models. This erasure, along with modified growth slopes and strong-coupling-induced oscillatory ringing, propagates quadratically into the scalar-induced gravitational wave background, producing spectral signatures (altered infrared scaling, suppressed peaks, frequency shifts, high-frequency modulations) that are distinguishable from single-field predictions and potentially detect-

What carries the argument

The Transport Equations Method (TEM) for the covariance matrix of a Gaussian two-field system, evolved with exact SR-USR-SR background kinematics; the bilinear interaction ζ'F between the adiabatic curvature perturbation and the entropic environment; the quadratic propagation of scalar power spectrum distortions into the scalar-induced gravitational wave background via second-order cosmological perturbation theory.

Load-bearing premise

The entire analysis rests on a Gaussian two-field effective Lagrangian with a purely bilinear interaction and a Born-Oppenheimer assumption that the environment is a stationary reservoir, meaning the results capture only two-point-level effects and cannot self-consistently predict primordial black hole formation, which depends on non-Gaussian statistics.

What would settle it

If future observations of the stochastic gravitational wave background by LISA or comparable instruments show the standard single-field USR interference dip preserved (rather than erased) in the relevant frequency band, or if they show no oscillatory modulations or altered infrared scalings in the strong-coupling regime, the environmental coupling scenarios predicted here would be constrained or ruled out.

Watch this falsifier — get emailed when new claim-graph text bears on it.

If this is right

  • If the predicted dip erasure and oscillatory features are observed in the gravitational wave background by LISA or similar instruments, they would simultaneously constrain the mass and coupling of hidden environmental fields active during inflation, providing a direct observational window into the quantum-to-classical transition.
  • The correlation between maximal decoherence rate (at m/H ≈ 1) and dip erasure suggests that the presence or absence of the interference dip in the power spectrum could serve as a diagnostic for whether decoherence occurred during the USR phase, linking quantum information properties to spectral shape observables.
  • The suppressed peak amplitudes under strong coupling would directly modify the predicted primordial black hole mass fraction and formation thresholds, potentially easing or tightening PBH dark matter constraints—though the paper notes this requires non-Gaussian extensions to fully quantify.
  • The finding that modes crossing during USR undergo violent, irreversible decoherence (except for very heavy environments that partially recohere) implies that the quantum state of perturbations relevant for structure formation is not a universal feature but depends critically on the timing of horizon crossing relative to the non-attractor phase.

Where Pith is reading between the lines

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

  • The Born-Oppenheimer assumption that the environment is stationary (footnote 3) means the environment does not back-react on the background dynamics. If the environment were dynamically coupled to the inflaton trajectory rather than treated as a reservoir, the SR-USR-SR transition itself could be modified, potentially altering the decoherence-spectral feature correspondence the paper establishes.
  • The strong-coupling regime λ/H = 5 is explored without discussion of whether the effective field theory remains valid at this coupling. If the EFT truncation breaks down for large λ, the oscillatory ringing and peak suppression predictions in this regime could be artifacts of the Lagrangian rather than physical effects, though the qualitative weak-coupling results (dip erasure at m/H ≈ 1) would re
  • The paper's Gaussian interaction closes the transport hierarchy at two-point level, but the PBH-relevant conclusions (suppressed peaks altering mass fractions) implicitly require non-Gaussian statistics. Extending to cubic interactions would not only open the bispectrum transport but could also feed back into the power spectrum through loop corrections, potentially modifying the very spectral feat

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit.

Referee Report

2 major / 7 minor

Summary. This manuscript studies the open quantum dynamics of the adiabatic curvature perturbation coupled to a massive entropic scalar environment during an inflationary background featuring a transient Ultra-Slow-Roll (USR) phase. The authors employ the exact Transport Equations Method (TEM) to evolve the full covariance matrix of a Gaussian two-field system across the SR-USR-SR transition, tracking quantum purity and von Neumann entropy. They find that environmental coupling modifies the primordial scalar power spectrum — erasing the pre-growth interference dip for m/H ~ 1, altering growth slopes, and inducing oscillatory ringing under strong coupling — and propagate these distortions to the scalar-induced gravitational wave (SIGW) background, claiming detectability with LISA. The transport equations for the 11-dimensional covariance system are derived in Appendix A from the quadratic Hamiltonian (Eq. 10), and the SIGW computation uses standard formulas via the public package SIGWfast.

Significance. The paper addresses a timely question at the intersection of quantum information theory and early-universe cosmology. The use of the exact transport equations method for a Gaussian system is a legitimate and well-implemented technical approach, and the exact treatment of the background kinematics across the SR-USR-SR transition is a genuine improvement over constant-H approximations. The identification of a correlation between rapid decoherence (m/H = 1) and dip erasure in the weak-coupling regime is an interesting physical observation. The SIGW computation is reproducible in principle via the cited public package. However, the observational significance of the headline results — order-1 spectral modifications, oscillatory ringing, and LISA-band detectability — rests almost entirely on the strong-coupling regime (λ/H = 5), which raises a self-consistency concern that is not addressed in the manuscript (see Major Comments).

major comments (2)
  1. §II.B, Eq. (6) and §IV.B (Fig. 3, right panel): The most observationally significant results — order-1 modifications to P_ζ, oscillatory ringing near the peak, and the LISA-detectability claim — are obtained in the strong-coupling regime λ/H = 5. The effective Lagrangian (Eq. 6) is a quadratic truncation of the full two-field action; the coupling λ enters both the bilinear mixing term (Eq. 10, Eq. A3) and the effective environmental mass M² = m² + λ² (Eq. A3). At λ/H = 5, the dimensionless coupling is not perturbatively small. During USR, the curvature perturbation reaches P_ζ ~ 10⁻² (ζ_rms ~ 0.1). Cubic interactions — present in any non-trivial two-field UV completion and neglected by the Gaussian closure — would generate loop corrections to the two-point function scaling roughly as (λ/H)² × P_ζ ~ 25 × 10⁻² ~ 0.25, which is not parametrically suppressed relative to the tree-level O(1)修改
  2. §IV.C, Fig. 4 (right panel) and Abstract: The LISA-detectability claim is the headline observational result of the paper. It depends on the strong-coupling results (λ/H = 5), which as noted above may not be self-consistent within the Gaussian truncation. The weak-coupling results (λ/H = 0.05), where the truncation is reliable, show only a highly localized spike in ΔΩ_GW at k ~ 10⁵ Mpc⁻¹ for m/H = 1 (Fig. 4, left panel), with the GW spectrum otherwise indistinguishable from the free case. The paper should either (i) provide a parametric estimate or explicit check that loop corrections remain subdominant at λ/H = 5, or (ii) qualify the LISA-detectability claim to reflect that it rests on a regime where the truncation has not been validated. Without this, the central observational claim is not adequately supported.
minor comments (7)
  1. §II.B, Eq. (6): The parameter λ is described as 'dimensionful' in the text following Eq. (6), but the ratio λ/H is used throughout as a dimensionless coupling. The dimensionality of λ and its relation to the dimensionless ratio λ/H should be clarified.
  2. §II.B, footnote 3: The Born-Oppenheimer assumption that the environment is stationary is stated but not justified quantitatively. A brief comment on the timescale separation argument would strengthen this assumption.
  3. §IV.B, Fig. 3: The y-axis label 'P_ζ(k)' lacks units or normalization annotation. The caption mentions CMB normalization P_ζ ~ 2.1 × 10⁻⁹ but the figure itself would benefit from explicit annotation.
  4. §IV.C, Eq. (23)-(24): The SIGW formula assumes a radiation-dominated universe at horizon reentry. The paper does not discuss whether the USR-enhanced modes reenter during radiation domination; a brief statement confirming this would be appropriate.
  5. Appendix A, Eq. (A4): The notation θ_N ≡ d ln z/dN is introduced but the relation z'/z = aH(1 + ε₂/2) is stated without derivation. A reference or one-line derivation would help the reader.
  6. §V: The paper acknowledges that non-Gaussian correlators are needed for PBH formation predictions but does not discuss whether the suppressed peak amplitudes in the strong-coupling regime (Fig. 3, right) could qualitatively change PBH formation prospects. A brief qualitative statement would be welcome.
  7. References: Several arXiv references use future-dated submissions (e.g., [44] arXiv:2607.00636, [57] arXiv:2606.07663, [58] arXiv:2512.01932, [47] arXiv:2512.14204). These should be verified for correctness.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for a careful and constructive report. The core technical methodology — exact transport equations for a Gaussian two-field system across the SR-USR-SR transition — is acknowledged as legitimate and well-implemented. The referee's major concern is that the most observationally significant results arise in the strong-coupling regime (λ/H = 5), where the quadratic (Gaussian) truncation of the effective Lagrangian may not be self-consistent due to neglected loop corrections from cubic interactions. We address this concern below and agree that the manuscript requires revision to qualify the observational claims accordingly.

read point-by-point responses
  1. Referee: §II.B, Eq. (6) and §IV.B (Fig. 3, right panel): The most observationally significant results — order-1 modifications to P_ζ, oscillatory ringing near the peak, and the LISA-detectability claim — are obtained in the strong-coupling regime λ/H = 5. The effective Lagrangian (Eq. 6) is a quadratic truncation of the full two-field action; the coupling λ enters both the bilinear mixing term (Eq. 10, Eq. A3) and the effective environmental mass M² = m² + λ² (Eq. A3). At λ/H = 5, the dimensionless coupling is not perturbatively small. During USR, the curvature perturbation reaches P_ζ ~ 10⁻² (ζ_rms ~ 0.1). Cubic interactions — present in any non-trivial two-field UV completion and neglected by the Gaussian closure — would generate loop corrections to the two-point function scaling roughly as (λ/H)² × P_ζ ~ 25 × 10⁻² ~ 0.25, which is not parametrically suppressed relative to the tree-level O(1) [

    Authors: The referee raises a valid and important point about the EFT validity of our quadratic truncation in the strong-coupling regime. We address it on two levels. First, a clarification of what is and is not exact in our calculation. Second, an acknowledgment of the genuine limitation. On the first point: the interaction Lagrangian (Eq. 6) contains a bilinear derivative mixing term λ a³ √(2ε) M_Pl ζ'F. The resulting Hamiltonian (Eq. 10) is exactly quadratic in the phase-space variables, and the transport equations (Appendix A) solve the full Gaussian dynamics without any perturbative expansion in λ. Within this specific quadratic theory, our results are exact — there are no loop corrections to the two-point function because the theory contains no cubic vertices. The Gaussian closure is not an approximation applied to a more general theory; it is a property of the specific Lagrangian we wrote down. On the second point: the referee is correct that any non-trivial UV completion of this two-field system would generically contain cubic and higher-order interactions (from the field-space metric, the potential, and the measure factor) that are absent from our quadratic truncation. At λ/H = 5 with P_ζ ~ 10⁻² during USR, the referee's parametric estimate of loop corrections ~(λ/H)² × P_ζ ~ O(0.1–1) is reasonable, and we cannot rule out that such corrections would quantitatively modify our strong-coupling spectra. We note that the parameter λ in our Lagrangian is dimensionful (it carries dimensions of mass), so λ/H = 5 does not correspond to a large dimensionless coupling per se; the relevant question is whether the omitted cubic vertices, whose coefficients depend on the UV completion, produce loop corrections comparable to the tree-level effects we compute. Without specifying a UV完成 revision: partial

  2. Referee: §IV.C, Fig. 4 (right panel) and Abstract: The LISA-detectability claim is the headline observational result of the paper. It depends on the strong-coupling results (λ/H = 5), which as noted above may not be self-consistent within the Gaussian truncation. The weak-coupling results (λ/H = 0.05), where the truncation is reliable, show only a highly localized spike in ΔΩ_GW at k ~ 10⁵ Mpc⁻¹ for m/H = 1 (Fig. 4, left panel), with the GW spectrum otherwise indistinguishable from the free case. The paper should either (i) provide a parametric estimate or explicit check that loop corrections remain subdominant at λ/H = 5, or (ii) qualify the LISA-detectability claim to reflect that it rests on a regime where the truncation has not been validated. Without this, the central observational claim is not adequately supported.

    Authors: The referee is correct that the LISA-detectability claim rests on the strong-coupling regime, and that the weak-coupling results — where the Gaussian truncation is most reliable — produce only a highly localized and modest feature in the GW spectrum. We agree that option (i), an explicit check that loop corrections remain subdominant at λ/H = 5, cannot be honestly provided within the current framework, as it would require extending the transport equations to the three-point function and coupling it back to the two-point system — a significant computational undertaking that we explicitly identify as future work in Section V. We therefore adopt option (ii): we will revise the manuscript to clearly qualify the LISA-detectability claim. Specifically, we will: (a) add a dedicated paragraph in Section IV.C (and a corresponding note in the Abstract) stating that the dramatic GW signatures and their potential LISA detectability arise in the strong-coupling regime (λ/H = 5), where the quadratic truncation has not been validated against loop corrections from cubic interactions that would be present in a UV completion; (b) add a parametric estimate of the expected loop corrections following the referee's scaling argument, explicitly stating the regime of validity; (c) emphasize that the weak-coupling results (λ/H = 0.05), which are robust within the Gaussian truncation, still produce a distinctive physical signature — the dip erasure for m/H = 1 and its corresponding localized GW feature — even if this feature is more modest in amplitude. We believe the weak-coupling dip-erasure result and its correlation with rapid decoherence is a robust and physically interesting finding that stands independently of the strong-coupling regime. revision: yes

Circularity Check

0 steps flagged

No significant circularity found; derivation is self-contained with minor non-load-bearing self-citations.

full rationale

The paper's derivation chain is self-contained. The background potential (Eq. 5) uses fixed parameter values from the literature [20, 67, 71] to produce the SR-USR-SR transition — these are model inputs, not fitted to the paper's predictions. The two-field effective Lagrangian (Eq. 6) is cited to [52] (Assassi, Baumann, Green, McAllister — external authors). The transport equations (Eqs. 16, A1–A5) are derived from the Hamiltonian (Eq. 10) via standard Heisenberg-picture differentiation; the method is cited to [38, 53, 81, 82], none of which are self-citations. The power spectrum P_ζ = Σ₁₁/z² (Eq. 22) is a direct readout of the covariance matrix element produced by solving the transport equations — it is not a fit to data, and the environmental parameters m/H and λ/H are scanned over fixed values (1.0, 1.5, 4.0 and 0.05, 5.0), not fitted to observations. The SIGW spectrum (Eqs. 23–24) is computed via the standard second-order integral using the external package SIGWfast [88], with P_ζ as input — the quadratic dependence is physical (second-order perturbation theory), not circular. The two self-citations present ([29] by Cielo, Mangano, Pisanti, Wands; [58] by Cielo, Scarlatella, Mangano, Pisanti, Hamaide) appear in the literature review for related USR/decoherence work but are not load-bearing for the central derivation: removing them would not affect any equation or result. No uniqueness theorem is invoked, no ansatz is smuggled via self-citation, and no prediction reduces to its inputs by construction. The score of 1 reflects the presence of minor self-citations that are non-load-bearing.

Axiom & Free-Parameter Ledger

6 free parameters · 4 axioms · 1 invented entities

See axiom entries above.

free parameters (6)
  • λ (inflaton self-coupling) = 1.86×10⁻⁶
    Parameter of the inflaton potential (Eq. 5), chosen to produce the SR-USR-SR transition and CMB-normalized amplitude.
  • ν (potential scale) = 0.196
    Parameter of the inflaton potential (Eq. 5).
  • a (potential shape) = 0.7071
    Parameter of the inflaton potential (Eq. 5).
  • b (potential shape) = 1.5
    Parameter of the inflaton potential (Eq. 5).
  • m/H (environmental mass ratio) = 1.0, 1.5, 4.0
    Scanned parameter controlling the environmental field mass; not fitted to data.
  • λ/H (interaction coupling ratio) = 0.05, 5.0
    Scanned parameter controlling the system-environment coupling strength; not fitted to data.
axioms (4)
  • domain assumption Born-Oppenheimer approximation: the environment is stationary and acts as a reservoir
    Invoked in footnote 3 (Sec. II.B) to justify the factorization of the initial density matrix and the tracing-out procedure. This is a standard assumption in open quantum system treatments of inflation but limits the generality of the results.
  • domain assumption The two-field effective Lagrangian (Eq. 6) with bilinear ζ'F coupling captures the relevant system-environment interaction
    The Lagrangian is taken from [52] (Assassi et al. 2014). It is a leading-order effective interaction; higher-order terms are neglected. The Gaussian closure depends on this being the dominant coupling.
  • standard math Bunch-Davies vacuum initial conditions deep inside the horizon
    Standard assumption in inflationary perturbation theory, imposed at k = 10³aH (Appendix A).
  • domain assumption Radiation-dominated universe for the SIGW computation
    The SIGW kernel T(u,v) in Eq. (24) assumes a radiation-dominated post-inflationary era. Alternative reheating histories would modify the GW spectrum.
invented entities (1)
  • Massive entropic scalar environment field F no independent evidence
    purpose: Mediates decoherence of the adiabatic curvature perturbation via bilinear coupling
    The field F is an effective degree of freedom representing hidden sectors. Its mass m and coupling λ are free parameters. The paper provides no independent collider or cosmological evidence for this specific field; it is a model ingredient. However, multi-field inflation generically predicts such sectors, so it is not ad hoc in the strong sense.

pith-pipeline@v1.1.0-glm · 19314 in / 4132 out tokens · 233209 ms · 2026-07-09T05:18:41.287914+00:00 · methodology

0 comments
read the original abstract

We study the open quantum dynamics of the adiabatic curvature perturbation interacting with a massive entropic scalar environment during an inflationary scenario featuring a transient Ultra-Slow-Roll phase. Working within a Gaussian two-field effective Lagrangian, we employ the exact Transport Equations Method to track the full non-unitary, non-Markovian evolution of the system's covariance matrix across the SR-USR-SR transition. We find that the efficiency of decoherence is sensitive to the background kinematics at horizon crossing. Most importantly, the interaction with the environment leaves distinct observable imprints on the primordial scalar power spectrum: the characteristic interference dip preceding the USR-driven enhancement can be partially or completely erased, the growth slope modified, and oscillatory features induced near the peak. Propagated to second order, these distortions further imprint on the stochastic background of Scalar-Induced Gravitational Waves, breaking single-field predictions and yielding unique spectral signatures potentially accessible to LISA. Our results demonstrate that the quantum environment is not a passive spectator during inflation, but an active agent whose imprint on the primordial universe may be within reach of the next generation of cosmological observations.

Figures

Figures reproduced from arXiv: 2607.07602 by Gianpiero Mangano, Mattia Cielo, Ofelia Pisanti, Simone Scarlatella.

Figure 1
Figure 1. Figure 1: FIG. 1. Evolution of the SR parameters showing the sharp [PITH_FULL_IMAGE:figures/full_fig_p002_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: FIG. 2. Evolution of Purity [PITH_FULL_IMAGE:figures/full_fig_p006_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: FIG. 3. Primordial power spectrum of the curvature perturbation for weak ( [PITH_FULL_IMAGE:figures/full_fig_p007_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: FIG. 4. Spectrum of Scalar-Induced Gravitational Waves Ω [PITH_FULL_IMAGE:figures/full_fig_p009_4.png] view at source ↗

discussion (0)

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Reference graph

Works this paper leans on

88 extracted references · 88 canonical work pages · 48 internal anchors

  1. [1]

    A. H. Guth, Phys. Rev. D23, 347 (1981)

  2. [2]

    A. A. Starobinsky, Phys. Lett. B91, 99 (1980)

  3. [3]

    A. D. Linde, Phys. Lett. B108, 389 (1982)

  4. [4]

    A. R. Liddle, P. Parsons, and J. D. Barrow, Physical 11 Review D50, 7222–7232 (1994)

  5. [5]

    V. F. Mukhanov and G. V. Chibisov, Sov. Phys. - JETP (Engl. Transl.); (United States)56:2(1982)

  6. [6]

    Allen, Phys

    B. Allen, Phys. Rev. D32, 3136 (1985)

  7. [7]

    Mukhanov, H

    V. Mukhanov, H. Feldman, and R. Brandenberger, Physics Reports215, 203 (1992)

  8. [8]

    The Effective Field Theory of Inflation

    C. Cheung, P. Creminelli, A. L. Fitzpatrick, J. Kaplan, and L. Senatore, J. High Energy Phys.2008, 014 (2008), arXiv:0709.0293 [hep-th]

  9. [9]

    Lemoine, J

    M. Lemoine, J. Martin, and P. Peter, eds.,Inflationary cosmology(2008)

  10. [10]

    Inflation, Cosmic Perturbations and Non-Gaussianities

    Y. Wang, Commun. Theor. Phys.62, 109 (2014), arXiv:1303.1523 [hep-th]

  11. [11]

    Baumann,Cosmology(Cambridge University Press, 2022)

    D. Baumann,Cosmology(Cambridge University Press, 2022)

  12. [12]

    B. Carr, F. K¨ uhnel, and M. Sandstad, Physical Review D94(2016), 10.1103/physrevd.94.083504

  13. [13]

    Carr and F

    B. Carr and F. K¨ uhnel, Annual Review of Nuclear and Particle Science70, 355–394 (2020)

  14. [14]

    B. Carr, K. Kohri, Y. Sendouda, and J. Yokoyama, Re- ports on Progress in Physics84, 116902 (2021)

  15. [15]

    Primordial Black Hole Formation in Starobinsky's Linear Potential Model

    S. Pi and J. Wang, J. Cosmol. Astropart. Phys.2023, 018 (2023), arXiv:2209.14183 [astro-ph.CO]

  16. [16]

    Garc´ ıa-Bellido and E

    J. Garc´ ıa-Bellido and E. Ruiz Morales, Physics of the Dark Universe18, 47 (2017)

  17. [17]

    Density Perturbations and Black Hole Formation in Hybrid Inflation

    J. Garcia-Bellido, A. D. Linde, and D. Wands, Phys. Rev. D54, 6040 (1996), arXiv:astro-ph/9605094

  18. [18]

    Quantum diffusion during inflation and primordial black holes

    C. Pattison, V. Vennin, H. Assadullahi, and D. Wands, J. Cosmol. Astropart. Phys.2017, 046 (2017), arXiv:1707.00537 [hep-th]

  19. [19]

    Seven Hints for Primordial Black Hole Dark Matter

    S. Clesse and J. Garc´ ıa-Bellido, Phys. Dark Univ.22, 137 (2018), arXiv:1711.10458 [astro-ph.CO]

  20. [20]

    J. M. Ezquiaga and J. Garc´ ıa-Bellido, Journal of Cosmol- ogy and Astroparticle Physics2018, 018–018 (2018)

  21. [21]

    The Primordial Black Hole Dark Matter - LISA Serendipity

    N. Bartolo, V. De Luca, G. Franciolini, A. Lewis, M. Peloso, and A. Riotto, Phys. Rev. Lett.122, 211301 (2019), arXiv:1810.12218 [astro-ph.CO]

  22. [22]

    Primordial black holes and their gravitational-wave signatures

    E. Baguiet al.(LISA Cosmology Working Group), Living Rev. Rel.28, 1 (2025), arXiv:2310.19857 [astro-ph.CO]

  23. [23]

    Inflation and Primordial Black Holes

    O. ¨Ozsoy and G. Tasinato, Universe9, 203 (2023), arXiv:2301.03600 [astro-ph.CO]

  24. [24]

    Primordial black hole dark matter from single field inflation

    G. Ballesteros and M. Taoso, Phys. Rev. D97, 023501 (2018), arXiv:1709.05565 [hep-ph]

  25. [25]

    S. M. Leach, M. Sasaki, D. Wands, and A. R. Liddle, Phys. Rev. D64, 023512 (2001), arXiv:astro-ph/0101406

  26. [26]

    W. H. Kinney, Phys. Rev. D72, 023515 (2005), arXiv:gr- qc/0503017

  27. [27]

    C. T. Byrnes, P. S. Cole, and S. P. Patil, J. Cosmol. As- tropart. Phys.2019, 028 (2019), arXiv:1811.11158 [astro- ph.CO]

  28. [28]

    R. N. Raveendran, K. Parattu, and L. Sriramku- mar, General Relativity and Gravitation54(2022), 10.1007/s10714-022-02974-9

  29. [29]

    Steepest Growth in the Primordial Power Spectrum from Excited States at a Sudden Transition

    M. Cielo, G. Mangano, O. Pisanti, and D. Wands, J. Cosmol. Astropart. Phys.2025, 007 (2025), arXiv:2410.22154 [astro-ph.CO]

  30. [30]

    R. H. Brandenberger, R. Laflamme, and M. Mijic, Mod. Phys. Lett. A5, 2311 (1990)

  31. [31]

    Semiclassicality and Decoherence of Cosmological Perturbations

    D. Polarski and A. A. Starobinsky, Class. Quant. Grav. 13, 377 (1996), arXiv:gr-qc/9504030

  32. [32]

    Quantum-to-classical transition for fluctuations in the early Universe

    C. Kiefer, D. Polarski, and A. A. Starobinsky, Int. J. Mod. Phys. D7, 455 (1998), arXiv:gr-qc/9802003

  33. [33]

    C. P. Burgess, R. Holman, and D. Hoover, Phys. Rev. D77, 063534 (2008), arXiv:astro-ph/0601646

  34. [34]

    Martin and V

    J. Martin and V. Vennin, JCAP2018, 063–063 (2018)

  35. [35]

    Martin and V

    J. Martin and V. Vennin, JCAP2018, 037–037 (2018)

  36. [36]

    Discord and Decoherence

    J. Martin, A. Micheli, and V. Vennin, JCAP04, 051 (2022), arXiv:2112.05037 [quant-ph]

  37. [37]

    C. P. Burgess, R. Holman, G. Kaplanek, J. Martin, and V. Vennin, J. Cosmol. Astropart. Phys.2023, 022 (2023), arXiv:2211.11046 [hep-th]

  38. [38]

    Quantum recoherence in the early universe

    T. Colas, J. Grain, and V. Vennin, EPL142, 69002 (2023), arXiv:2212.09486 [gr-qc]

  39. [39]

    Colas, C

    T. Colas, C. de Rham, and G. Kaplanek, Journal of Cosmology and Astroparticle Physics2024, 025 (2024)

  40. [40]

    Kranas, J

    D. Kranas, J. Grain, and V. Vennin, Phys. Rev. D112, 076014 (2025), arXiv:2504.18648 [quant-ph]

  41. [41]

    Quantum signatures and decoherence during inflation from deep subhorizon perturbations

    F. Lopez and N. Bartolo, “Quantum signatures and de- coherence during inflation from deep subhorizon pertur- bations,” (2025), arXiv:2503.23150 [astro-ph.CO]

  42. [42]

    Brahma, A

    S. Brahma, A. Berera, and J. Calder´ on-Figueroa, Class. Quant. Grav.39, 245002 (2022)

  43. [43]

    Is the CMB revealing signs of pre-inflationary physics?

    S. Brahma and J. Calder´ on-Figueroa, “Is the CMB revealing signs of pre-inflationary physics?” (2025), arXiv:2504.02746 [astro-ph.CO]

  44. [44]

    Hidden quantum-informatic symmetries of quasi-de Sitter backgrounds

    S. Brahma, J. Calderon-Figueroa, X. Luo, and V. Ven- nin, “Hidden quantum-informatic symmetries of quasi-de Sitter backgrounds,” (2026), arXiv:2607.00636 [hep-th]

  45. [45]

    Quantum cosmological gravitational waves?

    A. Micheli and P. Peter, “Quantum cosmological gravi- tational waves?” (2022), arXiv:2211.00182 [gr-qc]

  46. [46]

    M. P. Blencowe, Phys. Rev. Lett.111, 021302 (2013), arXiv:1211.4751 [quant-ph]

  47. [47]

    Cosmic Lockdown: When Decoherence Saves the Universe from Tunneling,

    R. Christie, J. b. Joo, G. Kaplanek, V. Vennin, and D. Wands, “Cosmic Lockdown: When Decoherence Saves the Universe from Tunneling,” (2025), arXiv:2512.14204 [hep-th]

  48. [48]

    T. J. Hollowood and J. I. McDonald, Phys. Rev. D95, 103521 (2017), arXiv:1701.02235 [gr-qc]

  49. [49]

    Benchmarking the cosmological master equations

    T. Colas, J. Grain, and V. Vennin, Eur. Phys. J. C82, 1085 (2022), arXiv:2209.01929 [hep-th]

  50. [50]

    Gauging Open EFTs from the top down

    G. Kaplanek, M. Mylova, and A. J. Tolley, “Gaug- ing Open EFTs from the top down,” (2025), arXiv:2512.17089 [hep-th]

  51. [51]

    Brahma, A

    S. Brahma, A. Berera, and J. Calder´ on-Figueroa, JHEP 2022(2022), 10.1007/jhep08(2022)225

  52. [52]

    Planck-Suppressed Operators

    V. Assassi, D. Baumann, D. Green, and L. McAl- lister, J. Cosmol. Astropart. Phys.2014, 033 (2014), arXiv:1304.5226 [hep-th]

  53. [53]

    The special case of slow-roll attractors in de Sitter: Non-Markovian noise and evolution of entanglement entropy

    S. Brahma, J. Calder´ on-Figueroa, X. Luo, and D. Seery, J. Cosmol. Astropart. Phys.2025, 050 (2025), arXiv:2411.08632 [hep-th]

  54. [54]

    Boyanovsky, Physical Review D98(2018), 10.1103/physrevd.98.023515

    D. Boyanovsky, Physical Review D98(2018), 10.1103/physrevd.98.023515

  55. [55]

    Boyanovsky, Physical Review D92(2015), 10.1103/physrevd.92.023527

    D. Boyanovsky, Physical Review D92(2015), 10.1103/physrevd.92.023527

  56. [56]

    C. P. Burgess, T. Colas, R. Holman, G. Kaplanek, and V. Vennin, JCAP08, 042 (2024), arXiv:2403.12240 [gr- qc]

  57. [57]

    A Landscape of Cosmological Decoherence

    S. S. Haque and B. Underwood, “A Landscape of Cosmo- logical Decoherence,” (2026), arXiv:2606.07663 [gr-qc]

  58. [58]

    Quantum recoherence in presence of excited states in the early universe,

    M. Cielo, S. Scarlatella, G. Mangano, O. Pisanti, and L. Hamaide, “Quantum recoherence in presence of excited states in the early universe,” (2025), arXiv:2512.01932 [gr-qc]

  59. [59]

    Cosmology with the Laser Interferometer Space Antenna

    P. Auclairet al.(LISA Cosmology Working Group), Living Rev. Rel.26, 5 (2023), arXiv:2204.05434 [astro- ph.CO]. 12

  60. [60]

    Probing Cosmic Inflation with the LiteBIRD Cosmic Microwave Background Polarization Survey

    E. Allyset al.(LiteBIRD), PTEP2023, 042F01 (2023), arXiv:2202.02773 [astro-ph.IM]

  61. [61]

    Measuring the spectrum of primordial gravitational waves with CMB, PTA and Laser Interferometers

    P. Campeti, E. Komatsu, D. Poletti, and C. Baccigalupi, JCAP01, 012 (2021), arXiv:2007.04241 [astro-ph.CO]

  62. [62]

    M. C. Guzzetti, N. Bartolo, M. Liguori, and S. Matar- rese, Riv. Nuovo Cim.39, 399 (2016), arXiv:1605.01615 [astro-ph.CO]

  63. [63]

    Ghaleb, A

    A. Ghaleb, A. Malhotra, G. Tasinato, and I. Zavala, Phys. Rev. D112, 123538 (2025), arXiv:2505.22534 [astro-ph.CO]

  64. [64]

    J. E. Gammalet al.(LISA Cosmology Working Group), J. Cosmol. Astropart. Phys.2025, 062 (2025), arXiv:2501.11320 [astro-ph.CO]

  65. [65]

    Exploring cosmological gravitational wave backgrounds through the synergy of LISA and ET

    A. Marriott-Best, D. Chowdhury, A. Ghoshal, and G. Tasinato, Phys. Rev. D111, 103001 (2025), arXiv:2409.02886 [astro-ph.CO]

  66. [66]

    Ultra slow-roll inflation demystified

    K. Dimopoulos, Phys. Lett. B775, 262 (2017), arXiv:1707.05644 [hep-ph]

  67. [67]

    Cheng, D.-S

    S.-L. Cheng, D.-S. Lee, and K.-W. Ng, Physics Letters B827, 136956 (2022)

  68. [68]

    A large $|\eta|$ approach to single field inflation

    G. Tasinato, Phys. Rev. D108, 043526 (2023), arXiv:2305.11568 [hep-th]

  69. [69]

    Bezrukov and M

    F. Bezrukov and M. Shaposhnikov, Physics Letters B 659, 703–706 (2008)

  70. [70]

    Garc´ ıa-Bellido, D

    J. Garc´ ıa-Bellido, D. G. Figueroa, and J. Rubio, Physical Review D79(2009), 10.1103/physrevd.79.063531

  71. [71]

    Primordial black holes from single field models of inflation

    J. Garcia-Bellido and E. Ruiz Morales, Phys. Dark Univ. 18, 47 (2017), arXiv:1702.03901 [astro-ph.CO]

  72. [72]

    Planck 2018 results. VI. Cosmological parameters

    N. Aghanimet al.(Planck), Astron. Astrophys.641, A6 (2020), [Erratum: Astron.Astrophys. 652, C4 (2021)], arXiv:1807.06209 [astro-ph.CO]

  73. [73]

    P. A. R. Adeet al.(BICEP, Keck), Phys. Rev. Lett.127, 151301 (2021), arXiv:2110.00483 [astro-ph.CO]

  74. [74]

    The Atacama Cosmology Telescope: DR6 Constraints on Extended Cosmological Models

    E. C. et al., “The atacama cosmology telescope: Dr6 constraints on extended cosmological models,” (2025), arXiv:2503.14454 [astro-ph.CO]

  75. [75]

    A. A. Starobinsky, JETP Lett.55, 489 (1992)

  76. [76]

    Time-convolutionless cosmological master equations: Late-time resummations and decoherence for non-local kernels

    S. Brahma, J. Calder´ on-Figueroa, and X. Luo, J. Cosmol. Astropart. Phys.2025, 019 (2025), arXiv:2407.12091 [hep-th]

  77. [77]

    Mukhanov and S

    V. Mukhanov and S. Winitzki,Introduction to quantum effects in gravity(Cambridge University Press, 2007)

  78. [78]

    Maggiore,Gravitational Waves

    M. Maggiore,Gravitational Waves. Vol. 2: Astrophysics and Cosmology(Oxford University Press, 2018)

  79. [79]

    Peter and J.-P

    P. Peter and J.-P. Uzan,Primordial Cosmology, Oxford Graduate Texts (Oxford University Press, 2013)

  80. [80]

    Wands, Phys

    D. Wands, Phys. Rev. D60, 023507 (1999), arXiv:gr- qc/9809062

Showing first 80 references.