pith. sign in

arxiv: 2606.28172 · v1 · pith:JQGX4ACXnew · submitted 2026-06-26 · 🌌 astro-ph.CO

Searching for primordial features with radio surveys: synergy between the power spectrum and bispectrum

Dionysios Karagiannis , Mario Ballardini , Roy Maartens This is my paper

Pith reviewed 2026-06-29 02:46 UTC · model grok-4.3

classification 🌌 astro-ph.CO
keywords primordial featuresbispectrumpower spectrumHI intensity mappingCMBinflationforecastingnon-Gaussian covariance
0
0 comments X

The pith

The bispectrum from future HI intensity mapping surveys improves constraints on primordial feature amplitudes by 30-40% over the power spectrum alone when combined with CMB data.

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

This paper sets out a forecasting framework to test how well next-generation radio surveys can detect oscillatory signals from the early universe. It demonstrates that adding the bispectrum to the power spectrum analysis tightens marginalised constraints by 30-40 percent, breaks degeneracies, and in some cases supplies more information than the power spectrum. Much of the added power comes from late-time gravitational contributions that carry forward the primordial oscillation pattern. When the HI data are combined with CMB measurements, the joint probe reaches percent-level precision on the frequency of these features, directly probing non-slow-roll inflation.

Core claim

The central claim is that a joint analysis of the redshift-space power spectrum and bispectrum from SKAO and HIRAX-style HI intensity mapping surveys, together with CMB data and including scale-dependent bias, redshift-space distortions and non-Gaussian covariance, improves marginalised constraints on the amplitudes of linear, logarithmic and sharp-feature primordial oscillations by 30-40 percent relative to the power spectrum alone, with the bispectrum sometimes containing more information than the power spectrum and the combined probe delivering percent-level precision on feature frequency.

What carries the argument

The joint redshift-space power spectrum plus bispectrum likelihood that incorporates phenomenological templates for linear, logarithmic and sharp-feature primordial oscillations, scale-dependent bias, redshift-space distortions and non-Gaussian covariance.

Load-bearing premise

The forecasting assumes that the chosen phenomenological templates accurately represent possible primordial features and that the modeled scale-dependent bias, redshift-space distortions and non-Gaussian covariance fully capture the relevant physics without unaccounted systematics.

What would settle it

Measurements from SKAO or HIRAX that show the bispectrum contributing less than 20 percent improvement to marginalised constraints on feature amplitudes, or that fail to reach percent-level precision on feature frequency when combined with CMB data, would falsify the forecasted gains.

read the original abstract

We present a comprehensive forecasting framework to assess the detection of primordial oscillatory features by exploiting the synergy between future neutral hydrogen (HI) intensity mapping (IM) surveys and cosmic microwave background (CMB) measurements. Focusing on next-generation single-dish (SKAO) and interferometric (HIRAX) radio configurations, we perform a joint analysis of the redshift-space power spectrum and bispectrum, consistently incorporating scale-dependent bias, redshift-space distortions, and non-Gaussian covariance. We investigate phenomenological templates with linear and logarithmic primordial oscillations, together with a physically motivated sharp-feature model. We find that including the large-scale structure bispectrum improves marginalised constraints on feature amplitudes by $30$--$40\%$ relative to the power spectrum alone and helps break parameter degeneracies. In several cases, the bispectrum contains more information on the power-spectrum feature parameters than the power spectrum itself. Much of this gain arises from the late-time gravitational contribution, which inherits the oscillatory structure of the primordial feature signal and acts as an independent source of information. While the CMB angular power spectrum is crucial for constraining low oscillation frequencies, joint interferometric IM analyses ($P+B$) outperform CMB amplitude constraints by up to $75\%$ in the linear regime. We also show that, despite non-Gaussian covariance degrading the independent constraining power of the bispectrum by $55$--$90\%$, the combined HI+CMB probe achieves percent-level precision on the frequency of primordial features, providing a powerful test of non-slow-roll inflation.

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 manuscript presents a forecasting study of constraints on primordial oscillatory features (linear, logarithmic, and sharp-feature templates) from future HI intensity mapping surveys (SKAO single-dish and HIRAX interferometric) combined with CMB data. It performs a joint Fisher-matrix analysis of the redshift-space power spectrum and bispectrum, incorporating scale-dependent bias, redshift-space distortions, and non-Gaussian covariance, and reports that the bispectrum improves marginalized constraints on feature amplitudes by 30-40%, breaks degeneracies, and enables percent-level precision on oscillation frequencies when combined with CMB.

Significance. If the modeling assumptions hold, the results indicate that bispectrum measurements from next-generation radio surveys can provide substantial complementary information to the power spectrum for testing non-slow-roll inflation, with the late-time gravitational contributions acting as an additional signal channel. The explicit inclusion of non-Gaussian covariance in the joint analysis is a methodological strength that makes the forecasts more realistic than many prior power-spectrum-only studies.

major comments (2)
  1. [Abstract / joint P+B covariance modeling] Abstract and the joint-analysis section: the headline 30-40% improvement and the claim that 'in several cases the bispectrum contains more information on the power-spectrum feature parameters than the power spectrum itself' rest on the assumption that the scale-dependent bias and RSD terms transmit the exact oscillatory structure of the primordial templates into the late-time bispectrum without significant additional damping or mode-coupling. This modeling choice is load-bearing for the reported information gain and degeneracy breaking; an explicit validation (e.g., against higher-order perturbation theory or simulations at the relevant k and z) is needed to confirm the inheritance is accurate.
  2. [Covariance and Fisher-matrix implementation] The non-Gaussian covariance degradation of 55-90% is quoted, yet the combined probe still achieves the stated gains. Because the off-diagonal correlations directly affect the marginalization over feature amplitudes and frequencies, the paper should demonstrate that the covariance matrix construction (including the specific template choices) does not underestimate correlations at the oscillation frequencies where the bispectrum is claimed to outperform the power spectrum.
minor comments (2)
  1. [Template definitions] The distinction between the linear, logarithmic, and sharp-feature templates should be summarized with explicit functional forms early in the methods section to aid readability.
  2. [Figures] Figure captions for the constraint contours should explicitly state whether the plotted ellipses include or exclude the CMB contribution so that the HI-only vs. joint gains are immediately clear.

Simulated Author's Rebuttal

2 responses · 1 unresolved

We thank the referee for their careful and constructive report. The comments raise important points regarding modeling assumptions and covariance validation. We respond to each major comment below and indicate the revisions made.

read point-by-point responses

  1. Referee: [Abstract / joint P+B covariance modeling] Abstract and the joint-analysis section: the headline 30-40% improvement and the claim that 'in several cases the bispectrum contains more information on the power-spectrum feature parameters than the power spectrum itself' rest on the assumption that the scale-dependent bias and RSD terms transmit the exact oscillatory structure of the primordial templates into the late-time bispectrum without significant additional damping or mode-coupling. This modeling choice is load-bearing for the reported information gain and degeneracy breaking; an explicit validation (e.g., against higher-order perturbation theory or simulations at the relevant k and z) is needed to confirm the inheritance is accurate.

    Authors: We agree that the transmission of oscillatory features through bias and RSD is a central modeling assumption. Our analysis employs the standard tree-level redshift-space bispectrum expressions, which by construction propagate the primordial templates. We have revised the manuscript by adding a dedicated paragraph in the methods section discussing the validity range of this approximation at the relevant scales (k < 0.2 h/Mpc) and redshifts, supported by references to higher-order perturbation theory studies. We have also moderated the abstract claim to 'the bispectrum provides complementary information' rather than 'contains more information'. Full N-body validation for these specific templates lies beyond the scope of the current forecasting work. revision: partial

  2. Referee: [Covariance and Fisher-matrix implementation] The non-Gaussian covariance degradation of 55-90% is quoted, yet the combined probe still achieves the stated gains. Because the off-diagonal correlations directly affect the marginalization over feature amplitudes and frequencies, the paper should demonstrate that the covariance matrix construction (including the specific template choices) does not underestimate correlations at the oscillation frequencies where the bispectrum is claimed to outperform the power spectrum.

    Authors: We have addressed this by adding new figures in the appendix that display the correlation matrix elements evaluated specifically at the oscillation frequencies of the linear and logarithmic templates. These confirm that off-diagonal correlations are fully incorporated in the covariance construction. The quoted degradation factors and the resulting joint constraints are obtained from the complete matrix inversion, and the gains remain robust. We have also clarified the covariance formula implementation in Section 4 to make the template dependence explicit. revision: yes

standing simulated objections not resolved
  • Full validation of the bispectrum modeling against N-body simulations for the oscillatory feature templates at the relevant k and z.

Circularity Check

0 steps flagged

No circularity: forecasting gains follow from standard perturbation theory applied to independent templates

full rationale

The paper's central results (30-40% improvement from adding bispectrum, degeneracy breaking, percent-level frequency precision) are obtained by propagating phenomenological templates (linear, logarithmic, sharp-feature) through the standard redshift-space power spectrum and bispectrum expressions that include scale-dependent bias and RSD. These expressions are not defined in terms of the final constraints; the numerical Fisher forecasts are external to the template definitions and do not reduce the reported information gain to a fitted parameter by construction. No self-citation is invoked as a uniqueness theorem or load-bearing premise for the templates themselves. The modeling assumptions are stated explicitly and remain falsifiable against external data or higher-order simulations.

Axiom & Free-Parameter Ledger

2 free parameters · 2 axioms · 0 invented entities

The central forecasting claim rests on standard cosmological assumptions and phenomenological templates whose parameters are the quantities being constrained rather than ad-hoc additions.

free parameters (2)
  • primordial feature amplitude
    Amplitude parameters of the oscillatory templates are the target quantities being forecasted; they are not fitted to existing data within the paper.
  • oscillation frequency
    Frequency parameters of the linear, logarithmic, and sharp-feature templates are constrained quantities.
axioms (2)
  • domain assumption Standard Lambda-CDM background and linear perturbation theory hold for the late-time evolution
    Invoked when incorporating scale-dependent bias, redshift-space distortions, and the late-time gravitational contribution that inherits the primordial oscillatory structure.
  • domain assumption The chosen phenomenological templates (linear, logarithmic, sharp-feature) adequately represent possible deviations from slow-roll inflation
    Used to generate the signals whose detectability is forecasted.

pith-pipeline@v0.9.1-grok · 5813 in / 1636 out tokens · 56956 ms · 2026-06-29T02:46:47.461343+00:00 · methodology

discussion (0)

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

Reference graph

Works this paper leans on

180 extracted references · 120 linked inside Pith

  1. [1]

    Aghanim, Y

    Planck Collaboration: N. Aghanim, Y. Akrami, M. Ashdown, J. Aumont, C. Baccigalupi, M. Ballardini et al.,Planck 2018 results. VI. Cosmological parameters, A&A641(2020) A6 [1807.06209]

    Pith/arXiv arXiv 2018

  2. [2]

    Akrami, F

    Planck Collaboration: Y. Akrami, F. Arroja, M. Ashdown, J. Aumont, C. Baccigalupi, M. Ballardini et al.,Planck 2018 results. X. Constraints on inflation, A&A641(2020) A10 [1807.06211]

    Pith/arXiv arXiv 2018

  3. [3]

    Akrami, F

    Planck Collaboration: Y. Akrami, F. Arroja, M. Ashdown, J. Aumont, C. Baccigalupi, M. Ballardini et al.,Planck 2018 results. IX. Constraints on primordial non-Gaussianity, A&A641(2020) A9 [1905.05697]

    Pith/arXiv arXiv 2018

  4. [4]

    Starobinsky,A new type of isotropic cosmological models without singularity,Physics Letters B91(1980) 99

    A.A. Starobinsky,A new type of isotropic cosmological models without singularity,Physics Letters B91(1980) 99

    1980

  5. [5]

    Guth,Inflationary universe: A possible solution to the horizon and flatness problems, Phys

    A.H. Guth,Inflationary universe: A possible solution to the horizon and flatness problems, Phys. Rev. D23(1981) 347

    1981

  6. [6]

    Linde,A new inflationary universe scenario: A possible solution of the horizon, flatness, homogeneity, isotropy and primordial monopole problems,Physics Letters B108(1982) 389

    A.D. Linde,A new inflationary universe scenario: A possible solution of the horizon, flatness, homogeneity, isotropy and primordial monopole problems,Physics Letters B108(1982) 389

    1982

  7. [7]

    Mukhanov and G.V

    V.F. Mukhanov and G.V. Chibisov,Quantum fluctuations and a nonsingular universe,Soviet Journal of Experimental and Theoretical Physics Letters33(1981) 532

    1981

  8. [8]

    Chluba, J

    J. Chluba, J. Hamann and S.P. Patil,Features and new physical scales in primordial observables: Theory and observation,International Journal of Modern Physics D24(2015) 1530023 [1505.01834]

    Pith/arXiv arXiv 2015

  9. [9]

    Achúcarro, M

    A. Achúcarro, M. Biagetti, M. Braglia, G. Cabass, R. Caldwell, E. Castorina et al.,Inflation: Theory and Observations,arXiv e-prints(2022) arXiv:2203.08128 [2203.08128]

    arXiv 2022

  10. [10]

    Adams, B

    J.A. Adams, B. Cresswell and R. Easther,Inflationary perturbations from a potential with a step,Phys. Rev. D64(2001) 123514 [astro-ph/0102236]

    Pith/arXiv arXiv 2001

  11. [11]

    Peiris, E

    H.V. Peiris, E. Komatsu, L. Verde, D.N. Spergel, C.L. Bennett, M. Halpern et al.,First-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Implications For Inflation, ApJS148(2003) 213 [astro-ph/0302225]

    Pith/arXiv arXiv 2003

  12. [12]

    Mukherjee and Y

    P. Mukherjee and Y. Wang,Model-independent Reconstruction of the Primordial Power Spectrum from Wilkinson Microwave Anistropy Probe Data,ApJ599(2003) 1 [astro-ph/0303211]

    Pith/arXiv arXiv 2003

  13. [13]

    Martin and C

    J. Martin and C. Ringeval,Superimposed oscillations in the WMAP data?,Phys. Rev. D69 (2004) 083515 [astro-ph/0310382]

    Pith/arXiv arXiv 2004

  14. [14]

    L. Covi, J. Hamann, A. Melchiorri, A. Slosar and I. Sorbera,Inflation and WMAP three year data: Features are still present,Phys. Rev. D74(2006) 083509 [astro-ph/0606452]

    Pith/arXiv arXiv 2006

  15. [15]

    Hamann, L

    J. Hamann, L. Covi, A. Melchiorri and A. Slosar,New constraints on oscillations in the primordial spectrum of inflationary perturbations,Phys. Rev. D76(2007) 023503 [astro-ph/0701380]. – 23 –

    Pith/arXiv arXiv 2007

  16. [16]

    Meerburg, R.A.M.J

    P.D. Meerburg, R.A.M.J. Wijers and J.P. van der Schaar,WMAP7 constraints on oscillations in the primordial power spectrum,MNRAS421(2012) 369 [1109.5264]

    Pith/arXiv arXiv 2012

  17. [17]

    Flauger, L

    R. Flauger, L. McAllister, E. Pajer, A. Westphal and G. Xu,Oscillations in the CMB from axion monodromy inflation,Journal of Cosmology and Astro-Particle Physics2010(2010) 009 [0907.2916]

    Pith/arXiv arXiv 2010

  18. [18]

    Aich, D.K

    M. Aich, D.K. Hazra, L. Sriramkumar and T. Souradeep,Oscillations in the inflaton potential: Complete numerical treatment and comparison with the recent and forthcoming CMB datasets, Phys. Rev. D87(2013) 083526 [1106.2798]

    Pith/arXiv arXiv 2013

  19. [19]

    Chen and C

    X. Chen and C. Ringeval,Searching for standard clocks in the primordial universe,Journal of Cosmology and Astro-Particle Physics2012(2012) 014 [1205.6085]

    Pith/arXiv arXiv 2012

  20. [20]

    Peiris, R

    H.V. Peiris, R. Easther and R. Flauger,Constraining monodromy inflation,Journal of Cosmology and Astro-Particle Physics2013(2013) 018 [1303.2616]

    Pith/arXiv arXiv 2013

  21. [21]

    Planck Collaboration: P. A. R. Ade, N. Aghanim, C. Armitage-Caplan, M. Arnaud, M. Ashdown, F. Atrio-Barandela et al.,Planck 2013 results. XXII. Constraints on inflation, A&A571(2014) A22 [1303.5082]

    Pith/arXiv arXiv 2013

  22. [22]

    Planck Collaboration: P. A. R. Ade, N. Aghanim, C. Armitage-Caplan, M. Arnaud, M. Ashdown, F. Atrio-Barandela et al.,Planck 2013 results. XXIV. Constraints on primordial non-Gaussianity, A&A571(2014) A24 [1303.5084]

    Pith/arXiv arXiv 2013

  23. [23]

    Meerburg, D.N

    P.D. Meerburg, D.N. Spergel and B.D. Wandelt,Searching for oscillations in the primordial power spectrum. II. Constraints from Planck data,Phys. Rev. D89(2014) 063537 [1308.3705]

    Pith/arXiv arXiv 2014

  24. [24]

    Benetti,Updating constraints on inflationary features in the primordial power spectrum with the Planck data,Phys

    M. Benetti,Updating constraints on inflationary features in the primordial power spectrum with the Planck data,Phys. Rev. D88(2013) 087302 [1308.6406]

    Pith/arXiv arXiv 2013

  25. [25]

    Miranda and W

    V. Miranda and W. Hu,Inflationary steps in the Planck data,Phys. Rev. D89(2014) 083529 [1312.0946]

    Pith/arXiv arXiv 2014

  26. [26]

    Easther and R

    R. Easther and R. Flauger,Planck constraints on monodromy inflation,Journal of Cosmology and Astro-Particle Physics2014(2014) 037 [1308.3736]

    Pith/arXiv arXiv 2014

  27. [27]

    Chen and M.H

    X. Chen and M.H. Namjoo,Standard Clock in primordial density perturbations and cosmic microwave background,Physics Letters B739(2014) 285 [1404.1536]

    Pith/arXiv arXiv 2014

  28. [28]

    Achúcarro, V

    A. Achúcarro, V. Atal, B. Hu, P. Ortiz and J. Torrado,Inflation with moderately sharp features in the speed of sound: Generalized slow roll and in-in formalism for power spectrum and bispectrum,Phys. Rev. D90(2014) 023511 [1404.7522]

    Pith/arXiv arXiv 2014

  29. [29]

    Hazra, A

    D.K. Hazra, A. Shafieloo, G.F. Smoot and A.A. Starobinsky,Wiggly whipped inflation, Journal of Cosmology and Astro-Particle Physics2014(2014) 048 [1405.2012]

    Pith/arXiv arXiv 2014

  30. [30]

    Hazra, A

    D.K. Hazra, A. Shafieloo and T. Souradeep,Primordial power spectrum from Planck,Journal of Cosmology and Astro-Particle Physics2014(2014) 011 [1406.4827]

    Pith/arXiv arXiv 2014

  31. [31]

    Hu and J

    B. Hu and J. Torrado,Searching for primordial localized features with CMB and LSS spectra, Phys. Rev. D91(2015) 064039 [1410.4804]

    Pith/arXiv arXiv 2015

  32. [32]

    Fergusson, H.F

    J.R. Fergusson, H.F. Gruetjen, E.P.S. Shellard and B. Wallisch,Polyspectra searches for sharp oscillatory features in cosmic microwave sky data,Phys. Rev. D91(2015) 123506 [1412.6152]

    arXiv 2015

  33. [33]

    Planck Collaboration: P. A. R. Ade, N. Aghanim, M. Arnaud, F. Arroja, M. Ashdown, J. Aumont et al.,Planck 2015 results. XVII. Constraints on primordial non-Gaussianity, A&A 594(2016) A17 [1502.01592]

    Pith/arXiv arXiv 2015

  34. [34]

    Planck Collaboration: P. A. R. Ade, N. Aghanim, M. Arnaud, F. Arroja, M. Ashdown, J. Aumont et al.,Planck 2015 results. XX. Constraints on inflation, A&A594(2016) A20 [1502.02114]. – 24 –

    Pith/arXiv arXiv 2015

  35. [35]

    Gruppuso, N

    A. Gruppuso, N. Kitazawa, N. Mandolesi, P. Natoli and A. Sagnotti,Pre-inflationary relics in the CMB?,Physics of the Dark Universe11(2016) 68 [1508.00411]

    Pith/arXiv arXiv 2016

  36. [36]

    Hazra, A

    D.K. Hazra, A. Shafieloo, G.F. Smoot and A.A. Starobinsky,Primordial features and Planck polarization,Journal of Cosmology and Astro-Particle Physics2016(2016) 009 [1605.02106]

    Pith/arXiv arXiv 2016

  37. [37]

    Torrado, B

    J. Torrado, B. Hu and A. Achúcarro,Robust predictions for an oscillatory bispectrum in Planck 2015 data from transient reductions in the speed of sound of the inflaton,Phys. Rev. D 96(2017) 083515 [1611.10350]

    Pith/arXiv arXiv 2015

  38. [38]

    Handley, A.N

    W.J. Handley, A.N. Lasenby, H.V. Peiris and M.P. Hobson,Bayesian inflationary reconstructions from Planck 2018 data,Phys. Rev. D100(2019) 103511 [1908.00906]

    arXiv 2018

  39. [39]

    Zeng, E.D

    C. Zeng, E.D. Kovetz, X. Chen, Y. Gong, J.B. Muñoz and M. Kamionkowski,Searching for oscillations in the primordial power spectrum with CMB and LSS data,Phys. Rev. D99 (2019) 043517 [1812.05105]

    Pith/arXiv arXiv 2019

  40. [40]

    Cañas-Herrera, J

    G. Cañas-Herrera, J. Torrado and A. Achúcarro,Bayesian reconstruction of the inflaton’s speed of sound using CMB data,Phys. Rev. D103(2021) 123531 [2012.04640]

    arXiv 2021

  41. [41]

    Braglia, X

    M. Braglia, X. Chen and D.K. Hazra,Comparing multi-field primordial feature models with the Planck data,Journal of Cosmology and Astro-Particle Physics2021(2021) 005 [2103.03025]

    arXiv 2021

  42. [42]

    Braglia, X

    M. Braglia, X. Chen and D.K. Hazra,Uncovering the history of cosmic inflation from anomalies in cosmic microwave background spectra,European Physical Journal C82(2022) 498 [2106.07546]

    arXiv 2022

  43. [43]

    Braglia, X

    M. Braglia, X. Chen and D.K. Hazra,Primordial standard clock models and CMB residual anomalies,Phys. Rev. D105(2022) 103523 [2108.10110]

    arXiv 2022

  44. [44]

    S.S. Naik, K. Furuuchi and P. Chingangbam,Particle production during inflation: a Bayesian analysis with CMB data from Planck 2018,Journal of Cosmology and Astro-Particle Physics 2022(2022) 016 [2202.05862]

    arXiv 2018

  45. [45]

    Hamann and J

    J. Hamann and J. Wons,Optimising inflationary features the Bayesian way,Journal of Cosmology and Astro-Particle Physics2022(2022) 036 [2112.08571]

    arXiv 2022

  46. [46]

    Antony, F

    A. Antony, F. Finelli, D.K. Hazra, D. Paoletti and A. Shafieloo,A search for super-imposed oscillations to the primordial power spectrum in Planck and SPT-3G 2018 data,arXiv e-prints (2024) arXiv:2403.19575 [2403.19575]

    arXiv 2018

  47. [47]

    Raffaelli and M

    A. Raffaelli and M. Ballardini,Knot reconstruction of the scalar primordial power spectrum with Planck, ACT, and SPT CMB data,Journal of Cosmology and Astro-Particle Physics 2025(2025) 077 [2503.10609]

    arXiv 2025

  48. [48]

    Raffaelli, M

    A. Raffaelli, M. Ballardini and N. Barbieri,Signals from the early Universe: a comprehensive search for primordial features in Planck CMB datasets,2605.30236

    Pith/arXiv arXiv

  49. [49]

    Beutler, M

    F. Beutler, M. Biagetti, D. Green, A. Slosar and B. Wallisch,Primordial features from linear to nonlinear scales,Physical Review Research1(2019) 033209 [1906.08758]

    arXiv 2019

  50. [50]

    Ballardini, F

    M. Ballardini, F. Finelli, F. Marulli, L. Moscardini and A. Veropalumbo,New constraints on primordial features from the galaxy two-point correlation function,Phys. Rev. D107(2023) 043532 [2202.08819]

    arXiv 2023

  51. [51]

    Mergulhão, F

    T. Mergulhão, F. Beutler and J.A. Peacock,Primordial feature constraints from BOSS + eBOSS,Journal of Cosmology and Astro-Particle Physics2023(2023) 012 [2303.13946]

    arXiv 2023

  52. [52]

    Calderon, T

    R. Calderon, T. Simon, A. Shafieloo and D.K. Hazra,Primordial Features in light of the Effective Field Theory of Large Scale Structure,arXiv e-prints(2025) arXiv:2504.06183 [2504.06183]

    arXiv 2025

  53. [53]

    X. Chen, R. Easther and E.A. Lim,Large non-Gaussianities in single-field inflation,Journal of Cosmology and Astro-Particle Physics2007(2007) 023 [astro-ph/0611645]. – 25 –

    Pith/arXiv arXiv 2007

  54. [54]

    Flauger and E

    R. Flauger and E. Pajer,Resonant non-gaussianity,Journal of Cosmology and Astro-Particle Physics2011(2011) 017 [1002.0833]

    Pith/arXiv arXiv 2011

  55. [55]

    Achúcarro, J.-O

    A. Achúcarro, J.-O. Gong, S. Hardeman, G.A. Palma and S.P. Patil,Features of heavy physics in the CMB power spectrum,Journal of Cosmology and Astro-Particle Physics2011(2011) 030 [1010.3693]

    Pith/arXiv arXiv 2011

  56. [56]

    Adshead, C

    P. Adshead, C. Dvorkin, W. Hu and E.A. Lim,Non-Gaussianity from step features in the inflationary potential,Phys. Rev. D85(2012) 023531 [1110.3050]

    Pith/arXiv arXiv 2012

  57. [57]

    Fergusson, H.F

    J.R. Fergusson, H.F. Gruetjen, E.P.S. Shellard and M. Liguori,Combining power spectrum and bispectrum measurements to detect oscillatory features,Phys. Rev. D91(2015) 023502 [1410.5114]

    Pith/arXiv arXiv 2015

  58. [58]

    Meerburg, M

    P.D. Meerburg, M. Münchmeyer and B. Wandelt,Joint resonant CMB power spectrum and bispectrum estimation,Phys. Rev. D93(2016) 043536 [1510.01756]

    Pith/arXiv arXiv 2016

  59. [59]

    Chen, P.D

    X. Chen, P.D. Meerburg and M. Münchmeyer,The future of primordial features with 21 cm tomography,Journal of Cosmology and Astro-Particle Physics2016(2016) 023 [1605.09364]

    Pith/arXiv arXiv 2016

  60. [60]

    Y. Xu, J. Hamann and X. Chen,Precise measurements of inflationary features with 21 cm observations,Phys. Rev. D94(2016) 123518 [1607.00817]

    Pith/arXiv arXiv 2016

  61. [61]

    Meerburg, M

    P.D. Meerburg, M. Münchmeyer, J.B. Muñoz and X. Chen,Prospects for cosmological collider physics,Journal of Cosmology and Astro-Particle Physics2017(2017) 050 [1610.06559]

    Pith/arXiv arXiv 2017

  62. [62]

    Ballardini, F

    M. Ballardini, F. Finelli, R. Maartens and L. Moscardini,Probing primordial features with next-generation photometric and radio surveys,Journal of Cosmology and Astro-Particle Physics2018(2018) 044 [1712.07425]. [63]SKAcollaboration,Cosmology with Phase 1 of the Square Kilometre Array: Red Book 2018: Technical specifications and performance forecasts,Publ...

    Pith/arXiv arXiv 2018

  63. [63]

    Castorina et al.,Redshift-weighted constraints on primordial non-Gaussianity from the clustering of the eBOSS DR14 quasars in Fourier space,JCAP09(2019) 010 [1904.08859]

    E. Castorina et al.,Redshift-weighted constraints on primordial non-Gaussianity from the clustering of the eBOSS DR14 quasars in Fourier space,JCAP09(2019) 010 [1904.08859]

    arXiv 2019

  64. [64]

    Mueller, M

    E.-M. Mueller, M. Rezaie, W.J. Percival, A.J. Ross, R. Ruggeri, H.-J. Seo et al.,The clustering of galaxies in the completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Primordial non-Gaussianity in Fourier Space,arXiv e-prints(2021) arXiv:2106.13725 [2106.13725]

    arXiv 2021

  65. [65]

    Philcox and M.M

    O.H.E. Philcox and M.M. Ivanov,BOSS DR12 full-shape cosmology:ΛCDM constraints from the large-scale galaxy power spectrum and bispectrum monopole,Phys. Rev. D105(2022) 043517 [2112.04515]

    arXiv 2022

  66. [66]

    Ivanov, O.H.E

    M.M. Ivanov, O.H.E. Philcox, T. Nishimichi, M. Simonović, M. Takada and M. Zaldarriaga, Precision analysis of the redshift-space galaxy bispectrum,Phys. Rev. D105(2022) 063512 [2110.10161]

    arXiv 2022

  67. [67]

    D’Amico, M

    G. D’Amico, M. Lewandowski, L. Senatore and P. Zhang,Limits on primordial non-Gaussianities from BOSS galaxy-clustering data,2201.11518

    arXiv

  68. [68]

    Cabass, M.M

    G. Cabass, M.M. Ivanov, O.H.E. Philcox, M. Simonović and M. Zaldarriaga,Constraints on Single-Field Inflation from the BOSS Galaxy Survey,Phys. Rev. Lett.129(2022) 021301 [2201.07238]

    arXiv 2022

  69. [69]

    Cabass, M.M

    G. Cabass, M.M. Ivanov, O.H.E. Philcox, M. Simonović and M. Zaldarriaga,Constraints on multifield inflation from the BOSS galaxy survey,Phys. Rev. D106(2022) 043506 [2204.01781]

    arXiv 2022

  70. [70]

    Sugiyama, D

    N.S. Sugiyama, D. Yamauchi, T. Kobayashi, T. Fujita, S. Arai, S. Hirano et al.,New – 26 – constraints on cosmological modified gravity theories from anisotropic three-point correlation functions of BOSS DR12 galaxies,2302.06808

    arXiv

  71. [71]

    Ivanov, O.H.E

    M.M. Ivanov, O.H.E. Philcox, G. Cabass, T. Nishimichi, M. Simonović and M. Zaldarriaga, Cosmology with the Galaxy Bispectrum Multipoles: Optimal Estimation and Application to BOSS Data,2302.04414

    arXiv

  72. [72]

    Cagliari, M

    M.S. Cagliari, M. Barberi-Squarotti, K. Pardede, E. Castorina and G. D’Amico,Bispectrum constraints on Primordial Non-Gaussianities with the eBOSS DR16 quasars,JCAP07(2025) 043 [2502.14758]

    arXiv 2025

  73. [73]

    Karagiannis, A

    D. Karagiannis, A. Slosar and M. Liguori,Forecasts on Primordial non-Gaussianity from 21 cm Intensity Mapping experiments,JCAP11(2020) 052 [1911.03964]

    arXiv 2020

  74. [74]

    Karagiannis, J

    D. Karagiannis, J. Fonseca, R. Maartens and S. Camera,Probing primordial non-Gaussianity with the power spectrum and bispectrum of future 21 cm intensity maps,Phys. Dark Univ.32 (2021) 100821 [2010.07034]

    arXiv 2021

  75. [75]

    Karagiannis, R

    D. Karagiannis, R. Maartens and L.F. Randrianjanahary,Cosmological constraints from the power spectrum and bispectrum of 21cm intensity maps,JCAP11(2022) 003 [2206.07747]

    arXiv 2022

  76. [76]

    Komatsu, N

    E. Komatsu, N. Afshordi, N. Bartolo, D. Baumann, J.R. Bond, E.I. Buchbinder et al., Non-Gaussianity as a Probe of the Physics of the Primordial Universe and the Astrophysics of the Low Redshift Universe,astro2010: The Astronomy and Astrophysics Decadal Survey2010 (2009) 158 [0902.4759]

    Pith/arXiv arXiv 2009

  77. [77]

    Starobinsky,Spectrum of adiabatic perturbations in the universe when there are singularities in the inflation potential,JETP Lett.55(1992) 489

    A.A. Starobinsky,Spectrum of adiabatic perturbations in the universe when there are singularities in the inflation potential,JETP Lett.55(1992) 489

    1992

  78. [78]

    X. Chen, R. Easther and E.A. Lim,Generation and Characterization of Large Non-Gaussianities in Single Field Inflation,JCAP04(2008) 010 [0801.3295]

    Pith/arXiv arXiv 2008

  79. [79]

    Chen,Folded Resonant Non-Gaussianity in General Single Field Inflation,JCAP12 (2010) 003 [1008.2485]

    X. Chen,Folded Resonant Non-Gaussianity in General Single Field Inflation,JCAP12 (2010) 003 [1008.2485]

    Pith/arXiv arXiv 2010

  80. [80]

    Stewart,Spectrum of density perturbations produced during inflation to leading order in a general slow-roll approximation,Phys

    E.D. Stewart,Spectrum of density perturbations produced during inflation to leading order in a general slow-roll approximation,Phys. Rev. D65(2002) 103508 [astro-ph/0110322]

    Pith/arXiv arXiv 2002

Showing first 80 references.