Pith. sign in

REVIEW 2 major objections 6 minor 1 cited by

Reconstructing a conventional cosmic-string gravitational-wave background to 10% precision with LISA requires a string tension roughly 100,000 times larger once all expected astrophysical foregrounds are included.

Reviewed by Pith at T0; open to challenge. T0 means a machine referee read the full paper against a public rubric. the ladder, T0–T4 →

T0 review · deepseek-v4-flash

2026-08-01 23:50 UTC pith:ATTMXC7Q

load-bearing objection Carefully executed mock-data study with a genuinely new and likely important result: including ExWD+EMRI foregrounds moves LISA's 10%-precision reconstruction threshold for BOS cosmic strings to Gmu ~ 1e-11, roughly two orders worse than the SOBHB+WD-only budget; but the headline threshold inherits the authors' deliberately pessimistic ExWD spectral choice, which is never propagated, so treat the the 2 major comments →

arxiv 2607.15219 v1 pith:ATTMXC7Q submitted 2026-07-16 astro-ph.CO gr-qchep-ph

Cosmic string gravitational wave backgrounds at LISA: II. Reconstruction of conventional signals over astrophysical foregrounds

classification astro-ph.CO gr-qchep-ph
keywords cosmic stringsgravitational wave backgroundLISAastrophysical foregroundssimulation-based inferencestochastic backgroundNambu-Goto stringsparameter reconstruction
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 asks what LISA can actually say about the cosmic-string gravitational-wave background once the astrophysical foregrounds that will sit on top of it are included. The authors inject a standard Nambu-Goto cosmic-string signal together with all major expected LISA foregrounds — galactic white dwarfs, extragalactic white dwarfs, stellar-origin black-hole binaries, extreme-mass-ratio inspirals, and massive black-hole binaries — and try to recover the string tension Gμ from mock LISA data using simulation-based inference. They find that reconstruction is far worse than foreground-free analyses suggested: reaching 10% precision on Gμ requires Gμ ≳ 1.7×10^-11 in the fiducial foreground model, about five orders of magnitude above the no-foreground threshold and two orders above a budget with only white-dwarf and SOBHB foregrounds. The key message is that a realistic foreground budget, not detector sensitivity alone, sets LISA's ability to test cosmic-string models.

Core claim

On the paper's own terms: with the full known astrophysical foreground budget, LISA's 10%-precision reconstruction threshold for the standard Nambu-Goto cosmic-string tension shifts from Gμ ≃ 4.2×10^-16 (no foregrounds) to Gμ ≃ 1.7×10^-11 (fiducial foregrounds); even the optimistic −1σ foreground model requires Gμ ≳ 3.9×10^-12, and the pessimistic +1σ model requires Gμ ≳ 2.3×10^-10, essentially at the current pulsar-timing bound. The dominant extra degradation comes from extragalactic white-dwarf binaries and EMRIs, not from the previously considered SOBHB plus WD budget. At Gμ = 10^-14 the foreground-aware reconstruction precision is roughly 90%, versus about 6% without foregrounds, and at

What carries the argument

The engine of the analysis is a joint posterior over the string tension log10 Gμ, LISA noise amplitudes, and the amplitudes of the WD, SOBHB, ExWD, and EMRI foregrounds, built with amortized simulation-based inference from hundreds of thousands of simulated LISA observations; the MBHB contribution is included as a fixed component. The cosmic-string signal uses the BOS template, a standard Nambu-Goto loop-network spectrum depending only on Gμ. Reconstruction precision is measured by δGμ, the width of the 95% highest-density interval on Gμ divided by the injected tension, and the results are cross-checked against MCMC and Fisher forecasts.

Load-bearing premise

The load-bearing assumption is that the fixed extragalactic-white-dwarf foreground spectrum used in the pipeline—a shallow-cutoff shape—is the right one in the frequency range where the cosmic-string signal peaks; the authors explicitly chose it over a newer spectrum with a sharper cutoff near 7 mHz, and that choice directly sets the headline threshold.

What would settle it

Run the identical reconstruction pipeline after replacing the extragalactic-white-dwarf foreground spectrum with the alternative model that cuts off sharply near 7 mHz. If the 10%-precision threshold falls well below Gμ ≈ 1.7×10^-11, the reported order-of-magnitude degradation is tied to the chosen foreground shape rather than to the mere presence of a full foreground budget.

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

If this is right

  • LISA's 10%-precision reach on the conventional string tension is Gμ ≳ 1.7×10^-11 with the fiducial foreground model, rather than Gμ ≳ 4.2×10^-16 in the foreground-free case.
  • The threshold moves with foreground amplitude: Gμ ≳ 3.9×10^-12 for a −1σ foreground shift and Gμ ≳ 2.3×10^-10 for a +1σ shift.
  • Under the easier 100%-precision criterion for a barely reconstructible signal, the minimum tension rises from about 2.1×10^-17 to about 7.2×10^-15, a 2.5-order-of-magnitude shift.
  • Extragalactic white dwarfs and EMRIs are the foregrounds that push the degradation beyond the previously studied WD plus SOBHB budget; omitting them understates the required tension by 1–2 orders of magnitude.
  • Coverage checks show the amortized posteriors remain well calibrated with seven inferred parameters, so the reported degradation is not an artifact of the inference method.

Where Pith is reading between the lines

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

  • If the newer extragalactic-white-dwarf spectrum with a sharper cutoff near 7 mHz is closer to reality, the headline thresholds would probably decrease substantially, because the paper deliberately chose the more conservative shallow-cutoff shape and did not propagate the newer model through the pipeline.
  • For cosmic-string models with more spectral structure than the BOS template, foreground contamination is likely to be even more damaging than shown here, since parameter degeneracies already reduce reconstruction quality in the foreground-free case.
  • A direct testable extension would rerun the same pipeline using the alternative ExWD spectrum, the newer WD foreground catalog, or a fully inferred MBHB component, to see how far the thresholds move.

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 / 6 minor

Summary. The paper presents a Simulation-Based Inference (SBI/NPE) framework, GWBackFinder, to reconstruct the cosmic-string tension Gμ from mock LISA data in the presence of the main astrophysical foregrounds: galactic white dwarfs (WDs), stellar-origin black-hole binaries (SOBHBs), extragalactic white dwarfs (ExWDs), extreme-mass-ratio inspirals (EMRIs), and massive black-hole binaries (MBHBs, held fixed). The authors jointly infer Gμ, the LISA instrumental noise amplitudes, and the foreground amplitudes, and quantify the 95% reconstruction precision δGμ as a function of injected Gμ. Their central result is that astrophysical foregrounds severely degrade reconstructions: achieving δGμ < 10% requires Gμ ≳ 1.7×10^{-11} in the fiducial foreground model, versus Gμ ≳ 4.2×10^{-16} without foregrounds — roughly 4–6 orders of magnitude — and about 2 orders of magnitude worse than a WD+SOBHB-only budget. The pipeline is validated via MCMC cross-checks, Fisher forecasts, and coverage tests.

Significance. If the headline thresholds hold, the paper is an important step for LISA cosmic-string science: it provides a quantitative, forward-model-based estimate of how the full astrophysical foreground budget impedes measurement of conventional (BOS) cosmic-string templates, and it corrects overly optimistic foreground-free projections. The strengths are substantial: a reusable amortized SBI pipeline, error bars from 20 independent mock realizations, independent MCMC validation, Fisher comparisons, and posterior-coverage checks. The main qualification is that the headline numbers are contingent on the adopted ExWD spectral shape, which is selected at the pessimistic end of available models; the paper is transparent about this choice but does not propagate the alternative shape through the analysis.

major comments (2)
  1. [Sec. II B c, Eq. (9); Sec. III] The ExWD foreground is fixed to the spectral shape of [25,26] (Eq. 9), and the newer [177] model, which has a sharper cutoff near 7 mHz, is explicitly rejected because the [25,26] foreground is 'more prominent'. Since Sec. III attributes most of the additional degradation (relative to WD+SOBHB-only) to ExWD and EMRI contributions, the headline thresholds Gμ ≳ 1.7×10^{-11} (fiducial) and Gμ ≳ 2.3×10^{-10} (pessimistic) are not expected values but conservative bounds under a deliberately pessimistic ExWD shape. The paper varies only foreground amplitudes, never the spectral shape; the [177] model is not run through SBI or MCMC. This is a load-bearing model contingency. I request either (i) a supplementary analysis with the [177] shape (at least a Fisher-matrix estimate, if a full SBI rerun is too costly), or (ii) an explicit restatement of the abstract/conclusions that these thresholds are
  2. [Abstract and Sec. IV] The summary-level claims — 'in the presence of the expected astrophysical foregrounds at LISA' and 'a dramatic 4–6 orders of magnitude increase' — are presented as robust expectations, but the magnitude of the shift is driven by the ExWD spectral choice discussed above. The authors are transparent about the choice in the body, but the abstract and conclusions do not carry the caveat. Since these statements are what will be cited, the conclusions should be rephrased to say that the 4–6 order-of-magnitude degradation is obtained for the [25,26]-type ExWD foreground, and that the exact factor is model-dependent; otherwise the reader may mistake a conservative foreground model for a measured expected level.
minor comments (6)
  1. [Sec. II B c] Typo: 'we strict to the result' should read 'we stick to the result'.
  2. [Sec. III, Table II] The text says MCMC agrees with SBI 'at a few % level for all tension values, except the smallest one'. Table II shows differences of ~13% at Gμ=10^{-15} (229.5% vs 200.1%) and ~11% at 10^{-13} (46.9% vs 52.1%). Although these are within realization scatter, the wording 'few %' is too strong; suggest 'within ~10–20% for the lower-tension cases'.
  3. [Appendix C vs Appendix D] The descriptions of the frequency rebinning differ slightly: App. C says 1000 macro-bins above 10^{-3} Hz plus fine bins below, while App. D says 1000 log-spaced bins in [10^{-3},0.5] Hz plus 970 fine bins in [3×10^{-5},10^{-3}] Hz. Both yield 1970 bins, but the wording should be harmonized for clarity.
  4. [General notation] Some variable names are inconsistent: AWD/AGal and ASOBHB/AExB are used interchangeably (Sec. II B and Table I). Also, the prior on log10 ASOBHB is quoted as 'AExB' in Sec. II B b.
  5. [Sec. II B e] The MBHB contribution is fixed to the HS scenario and not jointly inferred. This is justified as sub-leading, but the abstract's phrase 'joint inference on the LISA noise, foregrounds, and signal' could be misread. A one-sentence clarification in the abstract or introduction would help.
  6. [App. D] Typo: 'armotized' should be 'amortized'.

Circularity Check

0 steps flagged

No significant circularity: the reconstruction-precision thresholds are computed in-paper from the forward models and cross-validated with MCMC and coverage tests; headline numbers are model-contingent but not presupplied by construction.

full rationale

We walked the derivation chain. The cosmic-string GWB template is built from external Nambu-Goto simulation ingredients (Eqs. 2-4, Refs. [111,169,172]); the foreground spectral shapes and amplitude priors are taken from external population studies (Eqs. 5-11 and Table I, Refs. [22-27,174-176]); mock LISA data are generated from these same forward models (App. C); and the SBI/MCMC posteriors plus the reconstruction-precision metric deltaGmu (Eq. 13) are computed outputs, not inputs. The headline thresholds (Gmu ~ 1.7e-11 fiducial, 3.9e-12 optimistic, 2.3e-10 pessimistic for deltaGmu < 10%) are obtained by running the inference pipeline across injected tensions and reading off where the 95% HDI width crosses the threshold; they are not fitted parameters renamed as predictions. The foreground-free baseline is recomputed in-paper (Fig. 3 and Table II) rather than imported solely from Paper I, so the claimed 4-6 order-of-magnitude degradation is an internal comparison, not an input. Self-citations to Paper I supply the likelihood weighting, SBI implementation details, and the deltaGmu convention; these are methodological and are independently checked by the MCMC comparison and coverage calibration, so they are not load-bearing. The one substantive modeling caveat is the ExWD spectral choice: Sec. II B c explicitly adopts [25,26] over the newer [177] shape because the foreground effect is 'more prominent' there, and [177] is never propagated through the pipeline. This makes the exact thresholds model-contingent, i.e. conservative conditional forecasts, but it is a stated input-model selection rather than a step where an output is equivalent by construction to an input. We therefore find no circular step.

Axiom & Free-Parameter Ledger

6 free parameters · 6 axioms · 0 invented entities

The central claim is a reconstruction forecast, so it rests on the fidelity of the forward models (cosmic-string template, five foreground spectra, LISA noise) and the absence of inference bias. The explicitly fitted quantities are the four foreground normalizations plus two noise amplitudes; the MBHB component is the principal ad-hoc fixed input, and all spectral shapes are treated as known. No new physical entities are introduced.

free parameters (6)
  • log10 A_WD (galactic white-dwarf foreground normalization) = -7.84 (fiducial; prior σ=0.21)
    Inferred jointly with the signal; only the amplitude is varied, the spectral shape (Eq. 5) is fixed. Prior taken from [174,165].
  • log10 A_SOBHB (stellar-origin black-hole binary foreground normalization) = -12.38 (fiducial; prior σ=0.34)
    Inferred jointly; power-law shape f^{2/3} (Eq. 8) held fixed. Prior from [23,165].
  • log10 A_ExWD (extragalactic white-dwarf foreground normalization) = -11.06 (fiducial; prior σ=0.17)
    Inferred jointly; shape from [25,26] with the paper noting an alternative [177] shape exists but choosing the more prominent foreground model.
  • log10 A_EMRI (extreme-mass-ratio-inspiral foreground normalization at 3 mHz) = -11.34 (fiducial; prior σ=0.5)
    Inferred jointly; tabulated spectrum from [27] normalized at 3 mHz. Prior width σ=0.5 chosen by hand to account for possible uncertainties.
  • A_acc, A_P (LISA instrumental noise amplitudes) = A_acc=3, A_P=15 (fiducial; uniform priors ±20%)
    Inferred jointly in all runs; the ±20% prior range is a modeling choice from the companion paper.
  • Gμ (cosmic-string tension) = injected over [10^-18, 10^-9]
    The target physical parameter being reconstructed; its posterior width is the paper's central observable. Included for completeness.
axioms (6)
  • domain assumption Standard ΛCDM expansion history with Planck-2018 parameters and g*, g*s from [172] (Eq. 4)
    Input to the cosmic-string template and GW propagation; if early-universe cosmology differs, the template and hence the reconstruction thresholds change.
  • domain assumption BOS loop number density from NG simulation fits of [169] (Eq. 3) is the correct conventional cosmic-string model
    The paper adopts the NG-limit BOS template and notes (Sec. II A) that recent back-reaction simulations [144] lower the amplitude by ~20%; the VOS model differs by ≲20%. The headline thresholds inherit this template choice.
  • domain assumption Astrophysical foreground spectral shapes are known exactly; only their normalizations are uncertain (Eqs. 5–11)
    The inference varies only amplitudes. Shape uncertainty, e.g. the [177] sharper ExWD cutoff near 7 mHz, is not propagated into the reconstruction error.
  • domain assumption The mixed Gaussian+log-normal likelihood with 1/3–2/3 weighting calibrated in Paper I is accurate (Eqs. E1–E3)
    Used for MCMC cross-checks; the weighting is carried over from the authors' own Ref. [1] rather than re-derived here.
  • domain assumption Mock LISA data can be represented as 94 independent Gaussian chunks, coarse-grained to 1970 bins (App. C)
    Assumes stationary, Gaussian, uncorrelated time segments; ignores non-stationarity, correlated noise between channels beyond the A/E/T model, and residual confusion from sources that will be individually resolved and subtracted in real LISA analysis.
  • ad hoc to paper MBHB foreground can be fixed to the HS scenario of [27] without inference (Eq. 11)
    The paper argues the MBHB contribution is marginal above ~10^-4 Hz and thus can be held fixed; this is asserted rather than demonstrated by an explicit comparison run.

pith-pipeline@v1.3.0-alltime-deepseek · 5336 in / 5608 out tokens · 171213 ms · 2026-08-01T23:50:39.636022+00:00 · methodology

0 comments
read the original abstract

We study the reconstruction of conventional cosmic-string signals with LISA in the presence of all major known astrophysical foregrounds expected in the LISA band. These include stellar-origin black-hole binaries (SOBHBs), galactic (WDs) and extragalactic (ExWDs) white dwarfs, extreme-mass-ratio-inspirals (EMRIs), and massive black-hole binaries (MBHBs). Using the Simulation-based Inference package GWBackFinder, we perform a joint inference on the LISA noise, foregrounds, and signal, across a range of injected string tensions $G\mu$. We find that reconstructing tensions with an error $\lesssim 10\%$ requires values as large as $G\mu \gtrsim 10^{-11}$, i.e. a factor $\sim10^5$ larger than previous estimates with no foregrounds, and $\sim 10^2$ larger compared to estimates accounting only for SOBHB and WD foregrounds. This work is the second in a series initiated in Ref. arXiv:2508.05395, which aims to quantify LISA's ability to measure representative cosmic-string models.

Figures

Figures reproduced from arXiv: 2607.15219 by Androniki Dimitriou, Bryan Zaldivar, Daniel G. Figueroa, Isak Stomberg, Peera Simakachorn.

Figure 1
Figure 1. Figure 1: FIG. 1. An example of marginalized posterior distributions for a single mock LISA observation with astrophysical foregrounds [PITH_FULL_IMAGE:figures/full_fig_p006_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: FIG. 2. Reconstructed spectra for the cosmic string signal of [PITH_FULL_IMAGE:figures/full_fig_p007_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: FIG. 3. Reconstruction precision [PITH_FULL_IMAGE:figures/full_fig_p008_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: FIG. 4. Foreground-aware reconstruction precision from SBI [PITH_FULL_IMAGE:figures/full_fig_p009_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: FIG. 5. Reconstruction precision [PITH_FULL_IMAGE:figures/full_fig_p010_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: FIG. 6. Example marginalized posterior distributions for two single mock LISA observations with astrophysical foregrounds [PITH_FULL_IMAGE:figures/full_fig_p010_6.png] view at source ↗
Figure 7
Figure 7. Figure 7: FIG. 7. P–P plots for the foreground-free SBI model, showing empirical coverage as a function of confidence level for the [PITH_FULL_IMAGE:figures/full_fig_p013_7.png] view at source ↗
Figure 8
Figure 8. Figure 8: FIG. 8. P–P plots for the foreground-aware SBI model, showing empirical coverage for all seven inferred parameters: [PITH_FULL_IMAGE:figures/full_fig_p013_8.png] view at source ↗

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Forward citations

Cited by 1 Pith paper

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

  1. LISA Reconstruction Landscape for Metastable Cosmic Strings

    hep-ph 2026-07 conditional novelty 6.0

    LISA can reconstruct metastable cosmic-string tension and lifetime when it samples the tail-to-plateau transition, with residual κ_CS sensitivity possible even in high-SNR plateau-like spectra.

Reference graph

Works this paper leans on

154 extracted references · 136 linked inside Pith · cited by 1 Pith paper

  1. [1]

    Dimitriou, D

    A. Dimitriou, D. G. Figueroa, P. Simakachorn and B. Zaldivar,Cosmic string gravitational wave backgrounds at LISA: I. Signal survey, template reconstruction, and model comparison,JCAP05 (2026) 037 [2508.05395]. [2]LIGO Scientific, Virgocollaboration,Observation of Gravitational Waves from a Binary Black Hole Merger,Phys. Rev. Lett.116(2016) 061102 [1602.0...

  2. [12]

    D. J. Reardon et al.,Search for an Isotropic Gravitational-wave Background with the Parkes Pulsar Timing Array,Astrophys. J. Lett.951(2023) L6 [2306.16215]

  3. [13]

    Xu et al.,Searching for the Nano-Hertz Stochastic Gravitational Wave Background with the Chinese Pulsar Timing Array Data Release I,Res

    H. Xu et al.,Searching for the Nano-Hertz Stochastic Gravitational Wave Background with the Chinese Pulsar Timing Array Data Release I,Res. Astron. Astrophys.23(2023) 075024 [2306.16216]

  4. [14]

    Hild et al.,Sensitivity Studies for Third-Generation Gravitational Wave Observatories,Class

    S. Hild et al.,Sensitivity Studies for Third-Generation Gravitational Wave Observatories,Class. Quant. Grav. 28(2011) 094013 [1012.0908]

  5. [15]

    Punturo et al.,The Einstein Telescope: A third-generation gravitational wave observatory,Class

    M. Punturo et al.,The Einstein Telescope: A third-generation gravitational wave observatory,Class. Quant. Grav.27(2010) 194002. [16]ETcollaboration,The Science of the Einstein Telescope,JCAP03(2026) 081 [2503.12263]. [17]LIGO Scientificcollaboration,Exploring the Sensitivity of Next Generation Gravitational Wave Detectors,Class. Quant. Grav.34(2017) 04400...

  6. [18]

    Reitze et al.,Cosmic Explorer: The U.S

    D. Reitze et al.,Cosmic Explorer: The U.S. Contribution to Gravitational-Wave Astronomy beyond LIGO,Bull. Am. Astron. Soc.51(2019) 035 [1907.04833]. [19]LISAcollaboration,Laser Interferometer Space Antenna,1702.00786. [20]LISA Cosmology Working Groupcollaboration, Cosmology with the Laser Interferometer Space Antenna,Living Rev. Rel.26(2023) 5 [2204.05434...

  7. [22]

    Korol, N

    V. Korol, N. Hallakoun, S. Toonen and N. Karnesis, Observationally driven Galactic double white dwarf population for LISA,Mon. Not. Roy. Astron. Soc.511 (2022) 5936 [2109.10972]

  8. [23]

    Babak, C

    S. Babak, C. Caprini, D. G. Figueroa, N. Karnesis, P. Marcoccia, G. Nardini et al.,Stochastic gravitational wave background from stellar origin binary black holes in LISA,JCAP08(2023) 034 [2304.06368]

  9. [24]

    Pozzoli, S

    F. Pozzoli, S. Babak, A. Sesana, M. Bonetti and N. Karnesis,Computation of stochastic background from extreme-mass-ratio inspiral populations for LISA, Phys. Rev. D108(2023) 103039 [2302.07043]

  10. [25]

    Staelens and G

    S. Staelens and G. Nelemans,Likelihood of white dwarf binaries to dominate the astrophysical gravitational wave background in the mHz band,Astron. Astrophys. 683(2024) A139 [2310.19448]

  11. [26]

    Hofman and G

    S. Hofman and G. Nelemans,Uncertainty of the white dwarf astrophysical gravitational wave background, Astron. Astrophys.691(2024) A261 [2407.10642]

  12. [27]

    Perego, M

    A. Perego, M. Bonetti, A. Sesana, S. Toonen and V. Korol,Assessing the performance of future space-based detectors: astrophysical foregrounds and individual sources,2510.18695

  13. [28]

    Caprini and D

    C. Caprini and D. G. Figueroa,Cosmological backgrounds of gravitational waves,Class. Quant. Grav.35(2018) 163001 [1801.04268]

  14. [29]

    L. P. Grishchuk,Amplification of gravitational waves in an isotropic universe,Sov. Phys. JETP40(1975) 409

  15. [30]

    A. A. Starobinsky,Spectrum of relict gravitational radiation and the early state of the universe,JETP Lett.30(1979) 682

  16. [31]

    V. A. Rubakov, M. V. Sazhin and A. V. Veryaskin, Graviton Creation in the Inflationary Universe and the Grand Unification Scale,Phys. Lett. B115(1982) 189

  17. [32]

    Fabbri and M

    R. Fabbri and M. d. Pollock,The Effect of Primordially Produced Gravitons upon the Anisotropy of the Cosmological Microwave Background Radiation, Phys. Lett. B125(1983) 445

  18. [33]

    M. M. Anber and L. Sorbo,N-flationary magnetic fields,JCAP10(2006) 018 [astro-ph/0606534]

  19. [34]

    Sorbo,Parity violation in the Cosmic Microwave Background from a pseudoscalar inflaton,JCAP06 (2011) 003 [1101.1525]

    L. Sorbo,Parity violation in the Cosmic Microwave Background from a pseudoscalar inflaton,JCAP06 (2011) 003 [1101.1525]. 15

  20. [35]

    Pajer and M

    E. Pajer and M. Peloso,A review of Axion Inflation in the era of Planck,Class. Quant. Grav.30(2013) 214002 [1305.3557]

  21. [36]

    Adshead, E

    P. Adshead, E. Martinec and M. Wyman,Gauge fields and inflation: Chiral gravitational waves, fluctuations, and the Lyth bound,Phys. Rev. D88(2013) 021302 [1301.2598]

  22. [37]

    Adshead, E

    P. Adshead, E. Martinec and M. Wyman, Perturbations in Chromo-Natural Inflation,JHEP09 (2013) 087 [1305.2930]

  23. [38]

    Maleknejad,Axion Inflation with an SU(2) Gauge Field: Detectable Chiral Gravity Waves,JHEP07 (2016) 104 [1604.03327]

    A. Maleknejad,Axion Inflation with an SU(2) Gauge Field: Detectable Chiral Gravity Waves,JHEP07 (2016) 104 [1604.03327]

  24. [39]

    Dimastrogiovanni, M

    E. Dimastrogiovanni, M. Fasiello and T. Fujita, Primordial Gravitational Waves from Axion-Gauge Fields Dynamics,JCAP01(2017) 019 [1608.04216]

  25. [40]

    Namba, M

    R. Namba, M. Peloso, M. Shiraishi, L. Sorbo and C. Unal,Scale-dependent gravitational waves from a rolling axion,JCAP01(2016) 041 [1509.07521]

  26. [41]

    R. Z. Ferreira, J. Ganc, J. Nore˜ na and M. S. Sloth,On the validity of the perturbative description of axions during inflation,JCAP04(2016) 039 [1512.06116]

  27. [42]

    Peloso, L

    M. Peloso, L. Sorbo and C. Unal,Rolling axions during inflation: perturbativity and signatures,JCAP 09(2016) 001 [1606.00459]

  28. [43]

    Domcke, M

    V. Domcke, M. Pieroni and P. Bin´ etruy,Primordial gravitational waves for universality classes of pseudoscalar inflation,JCAP06(2016) 031 [1603.01287]

  29. [44]

    R. R. Caldwell and C. Devulder,Axion Gauge Field Inflation and Gravitational Leptogenesis: A Lower Bound on B Modes from the Matter-Antimatter Asymmetry of the Universe,Phys. Rev. D97(2018) 023532 [1706.03765]

  30. [45]

    M. C. Guzzetti, N. Bartolo, M. Liguori and S. Matarrese,Gravitational waves from inflation,Riv. Nuovo Cim.39(2016) 399 [1605.01615]

  31. [46]

    Bartolo et al.,Science with the space-based interferometer LISA

    N. Bartolo et al.,Science with the space-based interferometer LISA. IV: Probing inflation with gravitational waves,JCAP12(2016) 026 [1610.06481]

  32. [47]

    Fumagalli, S

    J. Fumagalli, S. Renaux-Petel and L. T. Witkowski, Oscillations in the stochastic gravitational wave background from sharp features and particle production during inflation,JCAP08(2021) 030 [2012.02761]

  33. [48]

    Fumagalli, G

    J. Fumagalli, G. A. Palma, S. Renaux-Petel, S. Sypsas, L. T. Witkowski and C. Zenteno,Primordial gravitational waves from excited states,JHEP03 (2022) 196 [2111.14664]

  34. [49]

    Easther and E

    R. Easther and E. A. Lim,Stochastic gravitational wave production after inflation,JCAP04(2006) 010 [astro-ph/0601617]

  35. [50]

    Garcia-Bellido and D

    J. Garcia-Bellido and D. G. Figueroa,A stochastic background of gravitational waves from hybrid preheating,Phys. Rev. Lett.98(2007) 061302 [astro-ph/0701014]

  36. [51]

    Garcia-Bellido, D

    J. Garcia-Bellido, D. G. Figueroa and A. Sastre,A Gravitational Wave Background from Reheating after Hybrid Inflation,Phys. Rev. D77(2008) 043517 [0707.0839]

  37. [52]

    J. F. Dufaux, A. Bergman, G. N. Felder, L. Kofman and J.-P. Uzan,Theory and Numerics of Gravitational Waves from Preheating after Inflation,Phys. Rev. D 76(2007) 123517 [0707.0875]

  38. [53]

    Dufaux, G

    J.-F. Dufaux, G. Felder, L. Kofman and O. Navros, Gravity Waves from Tachyonic Preheating after Hybrid Inflation,JCAP03(2009) 001 [0812.2917]

  39. [54]

    Dufaux, D

    J.-F. Dufaux, D. G. Figueroa and J. Garcia-Bellido, Gravitational Waves from Abelian Gauge Fields and Cosmic Strings at Preheating,Phys. Rev. D82(2010) 083518 [1006.0217]

  40. [55]

    Bethke, D

    L. Bethke, D. G. Figueroa and A. Rajantie, Anisotropies in the Gravitational Wave Background from Preheating,Phys. Rev. Lett.111(2013) 011301 [1304.2657]

  41. [56]

    Bethke, D

    L. Bethke, D. G. Figueroa and A. Rajantie,On the Anisotropy of the Gravitational Wave Background from Massless Preheating,JCAP06(2014) 047 [1309.1148]

  42. [57]

    Enqvist, D

    K. Enqvist, D. G. Figueroa and R. N. Lerner,Curvaton Decay by Resonant Production of the Standard Model Higgs,JCAP01(2013) 040 [1211.5028]

  43. [58]

    D. G. Figueroa and F. Torrenti,Gravitational wave production from preheating: parameter dependence, JCAP10(2017) 057 [1707.04533]

  44. [59]

    Adshead, J

    P. Adshead, J. T. Giblin and Z. J. Weiner, Gravitational waves from gauge preheating,Phys. Rev. D98(2018) 4 [1805.04550]

  45. [60]

    Adshead, J

    P. Adshead, J. T. Giblin, M. Pieroni and Z. J. Weiner, Constraining axion inflation with gravitational waves from preheating,Phys. Rev. D101(2020) 8 [1909.12842]

  46. [61]

    Adshead, J

    P. Adshead, J. T. Giblin, M. Pieroni and Z. J. Weiner, Constraining Axion Inflation with Gravitational Waves across 29 Decades in Frequency,Phys. Rev. Lett.124 (2020) 17 [1909.12843]

  47. [62]

    Giovannini,Gravitational waves constraints on postinflationary phases stiffer than radiation,Phys

    M. Giovannini,Gravitational waves constraints on postinflationary phases stiffer than radiation,Phys. Rev. D58(1998) 083504 [hep-ph/9806329]

  48. [63]

    Giovannini,Production and detection of relic gravitons in quintessential inflationary models,Phys

    M. Giovannini,Production and detection of relic gravitons in quintessential inflationary models,Phys. Rev. D60(1999) 123511 [astro-ph/9903004]

  49. [64]

    L. A. Boyle and A. Buonanno,Relating gravitational wave constraints from primordial nucleosynthesis, pulsar timing, laser interferometers, and the CMB: Implications for the early Universe,Phys. Rev. D78 (2008) 043531 [0708.2279]

  50. [65]

    B. Li, P. R. Shapiro and T. Rindler-Daller, Bose-Einstein-condensed scalar field dark matter and the gravitational wave background from inflation: new cosmological constraints and its detectability by LIGO, Phys. Rev. D96(2017) 063505 [1611.07961]

  51. [66]

    Li and P

    B. Li and P. R. Shapiro,Precision cosmology and the stiff-amplified gravitational-wave background from inflation: NANOGrav, Advanced LIGO-Virgo and the Hubble tension,JCAP10(2021) 024 [2107.12229]

  52. [67]

    D. G. Figueroa and E. H. Tanin,Inconsistency of an inflationary sector coupled only to Einstein gravity, JCAP10(2019) 050 [1811.04093]

  53. [68]

    D. G. Figueroa and E. H. Tanin,Ability of LIGO and LISA to probe the equation of state of the early Universe,JCAP08(2019) 011 [1905.11960]

  54. [69]

    Gouttenoire, G

    Y. Gouttenoire, G. Servant and P. Simakachorn, Revealing the Primordial Irreducible Inflationary Gravitational-Wave Background with a Spinning Peccei-Quinn Axion,2108.10328

  55. [70]

    R. T. Co, D. Dunsky, N. Fernandez, A. Ghalsasi, L. J. Hall, K. Harigaya et al.,Gravitational wave and CMB probes of axion kination,JHEP09(2022) 116 16 [2108.09299]

  56. [71]

    Gouttenoire, G

    Y. Gouttenoire, G. Servant and P. Simakachorn, Kination cosmology from scalar fields and gravitational-wave signatures,2111.01150

  57. [72]

    V. K. Oikonomou,Flat energy spectrum of primordial gravitational waves versus peaks and the NANOGrav 2023 observation,Phys. Rev. D108(2023) 043516 [2306.17351]

  58. [73]

    Er¨ oncel, Y

    C. Er¨ oncel, Y. Gouttenoire, R. Sato, G. Servant and P. Simakachorn,Universal Bound on the Duration of a Kination Era,Phys. Rev. Lett.135(2025) 101002 [2501.17226]

  59. [74]

    Ghiglieri and M

    J. Ghiglieri and M. Laine,Gravitational wave background from Standard Model physics: Qualitative features,JCAP07(2015) 022 [1504.02569]

  60. [75]

    Ghiglieri, G

    J. Ghiglieri, G. Jackson, M. Laine and Y. Zhu, Gravitational wave background from Standard Model physics: Complete leading order,JHEP07(2020) 092 [2004.11392]

  61. [76]

    Ringwald, J

    A. Ringwald, J. Sch¨ utte-Engel and C. Tamarit, Gravitational Waves as a Big Bang Thermometer, JCAP03(2021) 054 [2011.04731]

  62. [77]

    Ringwald and C

    A. Ringwald and C. Tamarit,Revealing the cosmic history with gravitational waves,Phys. Rev. D106 (2022) 063027 [2203.00621]

  63. [78]

    Ghiglieri, J

    J. Ghiglieri, J. Sch¨ utte-Engel and E. Speranza, Freezing-in gravitational waves,Phys. Rev. D109 (2024) 023538 [2211.16513]

  64. [79]

    Ghiglieri, M

    J. Ghiglieri, M. Laine, J. Sch¨ utte-Engel and E. Speranza,Double-graviton production from Standard Model plasma,JCAP04(2024) 062 [2401.08766]

  65. [80]

    S.-Y. Zhou, E. J. Copeland, R. Easther, H. Finkel, Z.-G. Mou and P. M. Saffin,Gravitational Waves from Oscillon Preheating,JHEP10(2013) 026 [1304.6094]

  66. [81]

    Antusch, F

    S. Antusch, F. Cefala and S. Orani,Gravitational waves from oscillons after inflation,Phys. Rev. Lett. 118(2017) 011303 [1607.01314]

  67. [82]

    Antusch, F

    S. Antusch, F. Cefala and S. Orani,What can we learn from the stochastic gravitational wave background produced by oscillons?,JCAP03(2018) 032 [1712.03231]

  68. [83]

    Liu, Z.-K

    J. Liu, Z.-K. Guo, R.-G. Cai and G. Shiu, Gravitational Waves from Oscillons with Cuspy Potentials,Phys. Rev. Lett.120(2018) 031301 [1707.09841]

  69. [84]

    M. A. Amin, J. Braden, E. J. Copeland, J. T. Giblin, C. Solorio, Z. J. Weiner et al.,Gravitational waves from asymmetric oscillon dynamics?,Phys. Rev. D98 (2018) 024040 [1803.08047]

  70. [85]

    Kamionkowski, A

    M. Kamionkowski, A. Kosowsky and M. S. Turner, Gravitational radiation from first order phase transitions,Phys. Rev. D49(1994) 2837 [astro-ph/9310044]

  71. [86]

    Caprini, R

    C. Caprini, R. Durrer and G. Servant,Gravitational wave generation from bubble collisions in first-order phase transitions: An analytic approach,Phys. Rev. D 77(2008) 124015 [0711.2593]

  72. [87]

    S. J. Huber and T. Konstandin,Gravitational Wave Production by Collisions: More Bubbles,JCAP09 (2008) 022 [0806.1828]

  73. [88]

    Hindmarsh, S

    M. Hindmarsh, S. J. Huber, K. Rummukainen and D. J. Weir,Gravitational waves from the sound of a first order phase transition,Phys. Rev. Lett.112 (2014) 041301 [1304.2433]

  74. [89]

    Hindmarsh, S

    M. Hindmarsh, S. J. Huber, K. Rummukainen and D. J. Weir,Numerical simulations of acoustically generated gravitational waves at a first order phase transition,Phys. Rev. D92(2015) 123009 [1504.03291]

  75. [90]

    Caprini et al.,Science with the space-based interferometer eLISA

    C. Caprini et al.,Science with the space-based interferometer eLISA. II: Gravitational waves from cosmological phase transitions,JCAP04(2016) 001 [1512.06239]

  76. [91]

    Hindmarsh, S

    M. Hindmarsh, S. J. Huber, K. Rummukainen and D. J. Weir,Shape of the acoustic gravitational wave power spectrum from a first order phase transition, Phys. Rev. D96(2017) 103520 [1704.05871]

  77. [92]

    Cutting, M

    D. Cutting, M. Hindmarsh and D. J. Weir, Gravitational waves from vacuum first-order phase transitions: from the envelope to the lattice,Phys. Rev. D97(2018) 123513 [1802.05712]

  78. [93]

    Cutting, M

    D. Cutting, M. Hindmarsh and D. J. Weir,Vorticity, kinetic energy, and suppressed gravitational wave production in strong first order phase transitions,Phys. Rev. Lett.125(2020) 021302 [1906.00480]

  79. [94]

    Roper Pol, S

    A. Roper Pol, S. Mandal, A. Brandenburg, T. Kahniashvili and A. Kosowsky,Numerical simulations of gravitational waves from early-universe turbulence,Phys. Rev. D102(2020) 083512 [1903.08585]

  80. [95]

    Caprini et al.,Detecting gravitational waves from cosmological phase transitions with LISA: an update, JCAP03(2020) 024 [1910.13125]

    C. Caprini et al.,Detecting gravitational waves from cosmological phase transitions with LISA: an update, JCAP03(2020) 024 [1910.13125]

Showing first 80 references.