Pith. sign in

REVIEW 4 major objections 6 minor 4 cited by

Challenges in the nonlinear evolution of unequal mass binaries in sGB gravity

T0 review · 4 major / 6 minor · reviewed 2026-08-06 · deepseek-v4-flash

Pith's one-line read First unequal-mass black hole mergers simulated in modified gravity

desk verdict First credible q=2 and q=3 sGB merger evolutions, with honest caveats; the quantitative dephasing is provisional because the horizon turn-off regulator is untested. read the letter →

arxiv 2507.13046 v1 pith:MYRXMJVP submitted 2025-07-17 gr-qc

classification gr-qc PACS 04.25.D04.30.-w04.50.Kd04.70.Bw
keywords scalar-Gauss-BonnetgravitybinaryblackholemergersunequalmassrationumericalrelativitygravitationalwavedephasinginitialdataeccentricityscalarizationmodifiedCCZ4formulation
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

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

The reading

Black holes in scalar-Gauss-Bonnet gravity carry scalar hair that changes the inspiral and merger, but numerical simulations have struggled to carry unequal-mass binaries through the merger. This paper reports the first full evolutions of 2:1 and 3:1 mass-ratio binaries through merger in shift-symmetric scalar-Gauss-Bonnet gravity, using a well-posed formulation that suppresses the coupling inside each horizon. At weak coupling the gravitational-wave dephasing relative to general relativity matches post-Newtonian predictions, supporting the analytic description in that regime. At larger coupling, close to the effective-field-theory limit, apparent deviations from post-Newtonian theory are traced to eccentricity introduced by the transient formation of scalar hair in the initial data, not to new physics. The paper argues that reliable precision waveforms will require scalarized, quasistationary, constraint-satisfying initial data with eccentricity reduction.

What carries the argument

The load-bearing mechanism is the ad hoc horizon turn-off: the scalar-Gauss-Bonnet coupling is smoothly suppressed inside each black hole horizon so that the weakly coupled, hyperbolic regime never breaks down, avoiding the elliptic regions that previously terminated unequal-mass evolutions at merger. A companion diagnostic is the weak-coupling condition $\sqrt{|\lambda f'(\phi)|}/L \ll 1$, where $L^{-1}$ is the largest curvature or scalar-gradient scale, which monitors whether the simulation stays inside the effective-field-theory's regime of validity. The dephasing measurement is carried by aligning general-relativity and scalar-Gauss-Bonnet waveforms at a chosen frequency $f_0=0.01/M_{\mathrm{ADM}}$ and comparing the orbital phase as a function of frequency against post-Newtonian expressions from prior work.

What would settle it

Run the $q=2$, $\lambda/m_1^2=0.106$ merger with the coupling turn-off boundary placed at two different radii well inside the horizon, keeping all other settings fixed; if the frequency-domain dephasing or the ringdown frequency changes by more than the measured convergence error, the horizon turn-off contaminates the exterior waveform and the central quantitative claim fails.

Watch

Extended reading notes

Core claim

The central claim is that unequal-mass black-hole binaries in shift-symmetric scalar-Gauss-Bonnet gravity can be evolved through merger with a modified CCZ4 scheme, provided the Gauss-Bonnet coupling is smoothly turned off inside each apparent horizon to prevent the formation of elliptic regions. For the mass ratio $q=2$ at weak coupling $\lambda/m_1^2=0.04$, the dephasing of the (2,2) gravitational-wave mode relative to general relativity agrees well with post-Newtonian predictions across the inspiral. At the larger coupling $\lambda/m_1^2=0.106$, near the weak-coupling limit, the measured dephasing deviates from post-Newtonian values, but the paper attributes this to eccentricity induced when the initially vanishing scalar field grows into hair and disturbs the binary trajectory; the ad hoc slow turn-on of the coupling helps in some cases and hurts in others, so it is not a reliable fix. The $q=3$ case also reaches merger, though with higher constraint violations and dephasing close to numerical error. The scalar monopole and dipole radiation scale with mass ratio as expected, and the post-merger ringdown shifts in the predicted direction but lies within numerical error.

Load-bearing premise

The results depend on the assumption that suppressing the modified-gravity coupling inside each black hole's horizon has no effect on the outside spacetime and gravitational waves, even though this suppression is an ad hoc procedure with no independent check of its innocuousness.

Editorial extensions

If this is right

  • 2:1 and 3:1 unequal-mass scalar-Gauss-Bonnet binaries can now be followed stably through merger, so beyond-GR waveform modeling extends beyond equal-mass, nonspinning cases.
  • In the weakly coupled regime, nonlinear numerical dephasing confirms post-Newtonian predictions, so post-Newtonian inspiral models can be used for data analysis in that regime.
  • Large-coupling dephasing discrepancies should be read as initial-data artifacts rather than as evidence for novel strong-field physics, until scalarized quasistationary initial data become available.
  • Reliable beyond-GR waveform catalogs will need constraint-satisfying scalarized initial data with eccentricity reduction; without them, dephasing measurements are sensitive to the alignment frequency and can be biased.
  • Post-merger ringdown frequency shifts are in the predicted direction but smaller than current numerical error, so accurate quasinormal-mode tests in this theory require higher resolution and more refined extraction.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • If the horizon turn-off is truly exterior-innocuous, the same strategy should extend stable evolutions to mass ratios beyond 3:1 and to other higher-curvature theories with elliptic-region breakdowns; this is testable by varying the turn-off shell radius.
  • The paper's identification of initial-data eccentricity as the dominant systematic suggests that current high-coupling dephasing values may shift once scalarized quasistationary initial data are used, potentially improving or eroding post-Newtonian agreement.
  • Because the remnant scalar charge is approximately independent of mass ratio after merger while the inspiral amplitude scales with the product of the masses, the jump in scalar monopole amplitude could serve as a clean probe of merger dynamics in future detections.
  • Once the initial-data problem is solved, the same pipeline can produce mismatches and parameter-estimation biases for future gravitational-wave detectors, quantifying how well parametrized general-relativity tests capture scalar-Gauss-Bonnet physics.
Share X Bluesky LinkedIn Reddit HN

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

4 major / 6 minor

Summary. The paper reports numerical relativity evolutions of unequal-mass binary black hole mergers in shift-symmetric Einstein-scalar-Gauss-Bonnet gravity, using the GRFolres extension of GRChombo with a modified CCZ4 formulation. It presents the first claimed full simulations through merger for mass ratios 2:1 and 3:1, together with equal-mass runs, and compares the gravitational-wave dephasing between GR and sGB with post-Newtonian predictions. For the weak-coupling q=2 case the dephasing is reported to agree with PN; for stronger couplings the deviations are attributed to eccentricity introduced by the initial-data scalar hair transient rather than to physical strong-field effects. The paper also studies scalar radiation modes and the ringdown, and devotes significant discussion to technical challenges including a coupling turn-off inside horizons, a slow turn-on of the coupling, and alignment-frequency choices.

Significance. If the technical claims are correct, this is a noteworthy advance: it extends sGB binary evolutions to unequal masses through merger, which previous work could not do at higher mass ratios. The paper is candid about its limitations, releases the code, and includes a clean convergence study in Appendix A showing fourth-to-sixth order convergence for the q=2 weak-coupling orbital phase; the independent PN comparison in Figure 3 is an appropriate validation target. However, the central quantitative claims are currently supported only weakly by the evidence: the horizon turn-off regulator used in all sGB runs is not validated, and the dephasing results lack quantified error bars. The contribution is therefore potentially important but needs the requested sensitivity and uncertainty analysis to be accepted as definitive.

major comments (4)
  1. [Section II D and footnote 1] The spatial regulator that smoothly turns off the sGB coupling inside the horizon is an ad hoc modification present in every sGB run and absent in the GR reference runs, yet the paper gives no implementation details (functional form of the profile, transition width, how the horizon is identified, whether the mask tracks the instantaneous horizon) and no sensitivity or convergence test for it. The authors themselves warn that unphysical errors can arise if the turn-off region is not contained within a well-resolved horizon. Because the same regulator is used in all sGB evolutions, it could contaminate the dephasing match in Figure 3 and the eccentricity attribution in Section III B; please add a sensitivity study that varies the turn-off profile and its width, and ideally a test with the regulator active in a GR run, to demonstrate that the exterior physics is unaffected.
  2. [Section III E and Figures 2-4] The dephasing curves are presented without quantified uncertainty, so the statements of "good agreement" with the PN prediction and "artificial deviations" for large coupling are not supported by error estimates. Appendix A only establishes convergence for the q=2, lambda/m_1^2=0.04 orbital phase, and not for the strong-coupling or unequal-mass runs; in addition, the alignment frequency f0 is chosen by hand and the text states that its value can change the dephasing significantly (Section III E). Please provide uncertainty bands from resolution differences, from allowed variations of f0, and from the slow turn-on variants, and show these bands on the dephasing curves.
  3. [Section III B and Appendix B] The attribution of the strong-coupling dephasing deviations to initial-data eccentricity is not directly established. The slow turn-on runs alter both the measured eccentricity and the dephasing, but correlation does not demonstrate causation, and no comparison is made with initial data from which the eccentricity has been removed or reduced by an independent method. A concrete test, for example evolving the same binary with eccentricity-reduced initial data or estimating the dephasing contribution of the residual eccentricity using the GR runs, is needed before the conclusion that the deviations are "artificial" can be accepted.
  4. [Section III B and the abstract] The q=3 case is presented as a full simulation through merger, but the paper explicitly says that "the constraint violations are higher" and that the dephasing "is also closer to the numerical error, and so we do not analyse it in detail." The abstract and the introductory claims should be qualified so that the reader understands that the detailed quantitative conclusions apply only to the q=1 and q=2 runs, and that the q=3 claim is limited to a successful evolution through merger.
minor comments (6)
  1. [Table I caption] The caption says "simulations presented in the papers"; this should be "in this paper."
  2. [Throughout] The abbreviations sGB and EsGB are used interchangeably; please define both or choose one and use it consistently.
  3. [Figure 1, top panel] The caption refers to the "average value of the weak coupling condition (11)", but Eq. (11) is an inequality; please specify exactly which quantity is averaged and plotted.
  4. [Figure 4] The legend does not cleanly distinguish the line styles for immediate versus slow turn-on in the left panel; please clarify.
  5. [Section III C and Figure 8] For the q=2 ringdown fit, the imaginary part moves away from the quoted sGB prediction (0.0801) rather than toward it, so the statement that both fitted values shift "in the right direction" is inaccurate for at least one component.
  6. [Footnote 1] The sentence "We understand from discussions with the authors of [54]..." is informal; if this information is retained, it should be attributed precisely or rephrased as a personal communication.

Circularity Check

0 steps flagged · score 1.0 of 10

No significant circularity: the dephasing and ringdown claims are benchmarked against independent PN and QNM results, and the paper's own ad hoc regulator is a systematic-risk caveat, not a definitional input.

full rationale

I found no circular step. The paper's central quantitative claim, that weak-coupling q=2 dephasing agrees with the post-Newtonian expectation, is checked against the PN expressions of Ref. [54], an external calculation by different authors, and against GR runs starting from identical initial data; the dephasing is a measured waveform difference, not a fitted quantity. The paper explicitly reports cases where the slow turn-on choice makes agreement worse, so the comparison is not selected to force a match. The horizon turn-off regulator described in Section II D is acknowledged as an ad hoc technique with a risk of unphysical errors, which is a legitimate correctness and systematics concern, but it is not circular: no predicted quantity is defined in terms of that regulator, and the claim is not derived from it. The modified CCZ4 formulation [28,29] and GRFolres code [72] are self-cited numerical machinery, but they are not the load-bearing prediction and are benchmarked in prior independent contexts. Ringdown comparisons are made against independent quasinormal-mode calculations [84,85]. No quantity in the paper is defined in terms of the target result, and no fitted parameter is renamed as a prediction.

Assumptions & free parameters 3 free parameters · 5 assumptions · 0 invented entities

No new particles or forces. The main extraneous knobs are numerical and analysis choices: alignment frequency, slow turn-on method, and the horizon turn-off of the coupling. The physical results also lean on the weak-coupling criterion and the PN benchmark, both external inputs.

free parameters (3)
  • Alignment frequency f0 = 0.01/MADM (some runs smaller)
    Hand-chosen frequency at which GR and sGB waveforms are aligned; the text says choosing too early or too late changes the dephasing significantly, so it is an analysis choice that affects the headline dephasing numbers.
  • Slow turn-on timescale and shape = not uniquely specified
    Ad hoc method used for some q=1 and q=2 runs; text says results were sensitive to the method and no simple strategy consistently worked, so the exact choice is a free knob.
  • Horizon coupling turn-off profile = not specified
    The coupling is smoothly turned off inside each horizon to avoid elliptic regions; the profile is not specified and the paper warns unphysical errors can result if it is not contained within a well-resolved horizon.
assumptions (5)
  • domain assumption Shift-symmetric sGB theory with f(phi)=phi and V=0 is the correct effective theory for the systems studied.
    Used throughout; Eq. (1). The paper does not justify this choice beyond prior literature.
  • domain assumption The modified CCZ4 formulation is strongly hyperbolic and reliable in the weak coupling regime.
    Invoked in Section II B, based on well-posedness results [28,29]; hyperbolicity is only guaranteed under weak coupling condition (11).
  • domain assumption The weak coupling condition Eq. (11) is a valid criterion for EFT validity.
    Used to argue high-coupling lambda/m1^2=0.106 runs are near the validity limit; this is a heuristic criterion, not a proven bound.
  • ad hoc to paper Zero scalar field initial data with dynamic scalarization is an acceptable approximation despite not being quasi-equilibrium.
    Section II D; the paper says this disturbs the trajectory and changes eccentricity. The admission means the initial data assumption is knowingly imperfect.
  • domain assumption PN dephasing expressions from [54] are accurate enough for comparison.
    Section II E; they note missing higher-order non-dipolar flux terms, assumed small by weak-field constraints [79].

how reviews work

0 comments
Cite this review

Pith. "Pith review of Challenges in the nonlinear evolution of unequal mass binaries in sGB gravity." pith.science (2026). https://pith.science/paper/MYRXMJVP

@misc{pith2026250713046,
  author       = {Pith},
  title        = {Pith review of: Challenges in the nonlinear evolution of unequal mass binaries in sGB gravity},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/MYRXMJVP}},
  note         = {Machine review of arXiv:2507.13046}
}
read the original abstract

It has only recently become possible to simulate the full nonlinear dynamics of binary black holes in scalar-Gauss-Bonnet theories of gravity. The simulations remain technically challenging and evolutions of unequal mass binaries in particular have been difficult to follow through the merger. Even when the merger is successful, accurately quantifying the physical dephasing, as opposed to contributions from transients in the initial data and gauge adjustments, remains difficult. We show the first full simulations of 2:1 and 3:1 binaries through merger, and we discuss how specific choices in the setup affect the dephasing observed and our ability to obtain reliable results. In cases with weaker couplings, we match the expected PN value for the dephasing, whereas for larger couplings, eccentricity introduced by the initial data transients can lead to artificial deviations. Our work highlights the need for improvements in the initial data methods used, to ensure reliable waveforms are obtained for data analysis in beyond-GR models.

Figures

Figures reproduced from arXiv: 2507.13046 by the authors.

Figure 1
Figure 1. FIG. 1. Overview of the [PITH_FULL_IMAGE:figures/full_fig_p003_1.png] view at source ↗
Figure 2
Figure 2. FIG. 2. A [PITH_FULL_IMAGE:figures/full_fig_p007_2.png] view at source ↗
Figure 3
Figure 3. FIG. 3. Dephasing between GR and sGB gravity in frequency domain for the simulation presented in Figure [PITH_FULL_IMAGE:figures/full_fig_p008_3.png] view at source ↗
Figures from the paper (9 more)
Figure 4
Figure 4. Figure 4: FIG. 4. Dephasing between GR and sGB waveforms for [PITH_FULL_IMAGE:figures/full_fig_p010_4.png]
Figure 5
Figure 5. Figure 5: FIG. 5. (2,2) mode of the [PITH_FULL_IMAGE:figures/full_fig_p011_5.png]
Figure 6
Figure 6. Figure 6: FIG. 6. The (0,0) mode of the scalar waves (scalar charge) for the three different mass ratios considered in [PITH_FULL_IMAGE:figures/full_fig_p012_6.png]
Figure 7
Figure 7. Figure 7: FIG. 7. (1,1) and (2,2) mode of the scalar waves for the three different mass ratios considered in shift [PITH_FULL_IMAGE:figures/full_fig_p012_7.png]
Figure 8
Figure 8. Figure 8: FIG. 8. Ringdown of the (2,2) mode of the Weyl scalar, for equal mass ( [PITH_FULL_IMAGE:figures/full_fig_p013_8.png]
Figure 9
Figure 9. Figure 9: FIG. 9. Dephasing between GR and non-GR (with [PITH_FULL_IMAGE:figures/full_fig_p015_9.png]
Figure 10
Figure 10. Figure 10: FIG. 10. Differences of the orbital phase [PITH_FULL_IMAGE:figures/full_fig_p016_10.png]
Figure 11
Figure 11. Figure 11: FIG. 11. The calculated eccentricity [PITH_FULL_IMAGE:figures/full_fig_p017_11.png]
Figure 12
Figure 12. Figure 12: FIG. 12. The calculated eccentricity [PITH_FULL_IMAGE:figures/full_fig_p018_12.png]

Discussion (0). Sign in to comment.

Forward citations

Cited by 4 Pith papers

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

  1. Scalar memory from compact binary coalescences

    gr-qc 2026-05 conditional novelty 7.0 of 10

    In Ricci-coupled scalar-Gauss-Bonnet gravity, the change in scalar charge during binary black hole mergers generates a scalar memory contribution that modifies the total memory signal on observable timescales.

  2. Spherically symmetric solutions in quasi-local Einstein-Weyl gravity

    gr-qc 2025-12 conditional novelty 7.0 of 10

    In quasi-local Einstein-Weyl gravity, static spherically symmetric Frobenius solutions are classified: regular cores only, Schwarzschild-like horizons and wormhole throats, plus asymptotic 1/r^6 corrections to Schwarzschild.

  3. Towards long and accurate numerical relativity waveforms of binary black holes beyond general relativity

    gr-qc 2026-07 conditional novelty 6.5 of 10

    Spectral methods plus comoving fixing-the-equations drivers yield 40+ cycle equal-mass sGB binary waveforms with phase error ≲1 rad, distinguishable from GR and merging earlier.

  4. Scalar fields from nonlinear sigma models on black hole spacetimes

    gr-qc 2025-08 conditional novelty 6.0 of 10

    Numerical evolutions show positive-curvature SL(2,R) sigma-model scalars create denser clouds and earlier binary mergers, while negative-curvature O(3) scalars spread out and delay mergers.

Reference graph

Works this paper leans on

89 extracted references · 2 canonical work pages · cited by 4 Pith papers

  1. [1]

    B. P . Abbott et al. (LIGO Scientific, Virgo), Observation of Gravitational Waves from a Binary Black Hole Merger, Phys. Rev. Lett. 116, 061102 (2016), arXiv:1602.03837 [gr-qc]

  2. [2]

    Our results show a good agreement between the PN dephasing and our nonlinear simulations

    We also show the post-Newtonian prediction for the dephasing calculated at different PN orders. Our results show a good agreement between the PN dephasing and our nonlinear simulations. E. Measure of the dephasing between GR and non-GR waveforms We measure the dephasing in the gravitational waves as a function of the frequency, compar- ing the same initia...

  3. [3]

    B. P . Abbott et al. (LIGO Scientific, Virgo), Tests of General Relativity with the Binary Black Hole Signals from the LIGO-Virgo Catalog GWTC-1, Phys. Rev. D100, 104036 (2019), arXiv:1903.04467 [gr- qc]

  4. [4]

    Abbott et al

    R. Abbott et al. (LIGO Scientific, Virgo), Tests of general relativity with binary black holes from the second LIGO-Virgo gravitational-wave transient catalog, Phys. Rev. D 103, 122002 (2021), arXiv:2010.14529 [gr-qc]

  5. [5]

    Abbott et al

    R. Abbott et al. (LIGO Scientific, VIRGO, KAGRA), Tests of General Relativity with GWTC-3, (2021), arXiv:2112.06861 [gr-qc]

  6. [6]

    Amaro-Seoane et al

    P . Amaro-Seoane et al. (LISA), Laser Interferometer Space Antenna, (2017), arXiv:1702.00786 [astro- ph.IM]

  7. [7]

    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, 194002 (2010)

  8. [8]

    Maggiore et al

    M. Maggiore et al. (ET), Science Case for the Einstein Telescope, JCAP03, 050, arXiv:1912.02622 [astro- ph.CO]

Show all 89 references
  1. [9]

    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, 035 (2019), arXiv:1907.04833 [astro-ph.IM]

  2. [10]

    K. G. Arun et al. (LISA), New horizons for fundamental physics with LISA, Living Rev. Rel. 25, 4 (2022), arXiv:2205.01597 [gr-qc]. 18 150 200 250 300 350 400 450 500 550 600 t/MADM −0.03 −0.02 −0.01 0.00 0.01 0.02 0.03 0.04 eΦ GR λ/m2 1 = 0.04 (no slow turn-on) λ/m2 1 = 0.106 ...

  3. [11]

    S. E. Perkins, N. Yunes, and E. Berti, Probing Fundamental Physics with Gravitational Waves: The Next Generation, Phys. Rev. D 103, 044024 (2021), arXiv:2010.09010 [gr-qc]

  4. [12]

    Barausse et al

    E. Barausse et al. , Prospects for Fundamental Physics with LISA, Gen. Rel. Grav. 52, 81 (2020), arXiv:2001.09793 [gr-qc]

  5. [13]

    Gnocchi, A

    G. Gnocchi, A. Maselli, T. Abdelsalhin, N. Giacobbo, and M. Mapelli, Bounding alternative theories of gravity with multiband GW observations, Phys. Rev. D 100, 064024 (2019), arXiv:1905.13460 [gr-qc]

  6. [14]

    Barack et al., Black holes, gravitational waves and fundamental physics: a roadmap, Class

    L. Barack et al., Black holes, gravitational waves and fundamental physics: a roadmap, Class. Quant. Grav. 36, 143001 (2019), arXiv:1806.05195 [gr-qc]

  7. [15]

    Baker, D

    T. Baker, D. Psaltis, and C. Skordis, Linking Tests of Gravity On All Scales: from the Strong-Field Regime to Cosmology, Astrophys. J. 802, 63 (2015), arXiv:1412.3455 [astro-ph.CO]

  8. [16]

    Maggio, H

    E. Maggio, H. O. Silva, A. Buonanno, and A. Ghosh, Tests of general relativity in the nonlinear regime: A parametrized plunge-merger-ringdown gravitational waveform model, Phys. Rev. D 108, 024043 (2023), arXiv:2212.09655 [gr-qc]

  9. [17]

    Pompili, E

    L. Pompili, E. Maggio, H. O. Silva, and A. Buonanno, A parametrized spin-precessing inspiral-merger- ringdown waveform model for tests of general relativity, (2025), arXiv:2504.10130 [gr-qc]

  10. [18]

    N. V . Krishnendu and F. Ohme, Testing General Relativity with Gravitational Waves: An Overview, Universe 7, 497 (2021), arXiv:2201.05418 [gr-qc]

  11. [19]

    Carson and K

    Z. Carson and K. Yagi, Parametrized and inspiral-merger-ringdown consistency tests of gravity with multiband gravitational wave observations, Phys. Rev. D101, 044047 (2020), arXiv:1911.05258 [gr-qc]

  12. [20]

    Cornish, L

    N. Cornish, L. Sampson, N. Yunes, and F. Pretorius, Gravitational Wave Tests of General Relativity with the Parameterized Post-Einsteinian Framework, Phys. Rev. D 84, 062003 (2011), arXiv:1105.2088 [gr-qc]

  13. [21]

    J. E. Thompson, E. Hamilton, L. London, S. Ghosh, P . Kolitsidou, C. Hoy, and M. Hannam, Phe- 19 nomXO4a: a phenomenological gravitational-wave model for precessing black-hole binaries with higher multipoles and asymmetries, Phys. Rev. D 109, 063012 (2024), arXiv:2312.10025 [gr-qc]

  14. [22]

    Ghosh, P

    S. Ghosh, P . Kolitsidou, and M. Hannam, First frequency-domain phenomenological model of the multipole asymmetry in gravitational-wave signals from binary-black-hole coalescence, Phys. Rev. D 109, 024061 (2024), arXiv:2310.16980 [gr-qc]

  15. [23]

    Wardell, A

    B. Wardell, A. Pound, N. Warburton, J. Miller, L. Durkan, and A. Le Tiec, Gravitational Wave- forms for Compact Binaries from Second-Order Self-Force Theory, Phys. Rev. Lett.130, 241402 (2023), arXiv:2112.12265 [gr-qc]

  16. [24]

    Blanchet, G

    L. Blanchet, G. Faye, Q. Henry, F. Larrouturou, and D. Trestini, Gravitational-Wave Phasing of Qua- sicircular Compact Binary Systems to the Fourth-and-a-Half Post-Newtonian Order, Phys. Rev. Lett. 131, 121402 (2023), arXiv:2304.11185 [gr-qc]

  17. [25]

    Dhani, S

    A. Dhani, S. V ¨olkel, A. Buonanno, H. Estell ´es, J. Gair, H. P . Pfeiffer, L. Pompili, and A. Toubiana, Systematic Biases in Estimating the Properties of Black Holes Due to Inaccurate Gravitational-Wave Models, (2024), arXiv:2404.05811 [gr-qc]

  18. [26]

    N. A. Wittek, L. Barack, H. P . Pfeiffer, A. Pound, N. Deppe, L. E. Kidder, A. Macedo, K. C. Nelli, W. Throwe, and N. L. Vu, Relieving Scale Disparity in Binary Black Hole Simulations, Phys. Rev. Lett. 134, 251402 (2025), arXiv:2410.22290 [gr-qc]

  19. [27]

    A. D. Kov ´acs and H. S. Reall, Well-Posed Formulation of Scalar-Tensor Effective Field Theory, Phys. Rev. Lett. 124, 221101 (2020), arXiv:2003.04327 [gr-qc]

  20. [28]

    A. D. Kov ´acs and H. S. Reall, Well-posed formulation of Lovelock and Horndeski theories, Phys. Rev. D 101, 124003 (2020), arXiv:2003.08398 [gr-qc]

  21. [29]

    Arest ´e Sal ´o, K

    L. Arest ´e Sal ´o, K. Clough, and P . Figueras, Well-Posedness of the Four-Derivative Scalar-Tensor Theory of Gravity in Singularity Avoiding Coordinates, Phys. Rev. Lett. 129, 261104 (2022), arXiv:2208.14470 [gr-qc]

  22. [30]

    Arest ´e Sal ´o, K

    L. Arest ´e Sal ´o, K. Clough, and P . Figueras, Puncture gauge formulation for Einstein-Gauss-Bonnet gravity and four-derivative scalar-tensor theories in d+1 spacetime dimensions, Phys. Rev. D 108, 084018 (2023), arXiv:2306.14966 [gr-qc]

  23. [31]

    Healy, T

    J. Healy, T. Bode, R. Haas, E. Pazos, P . Laguna, D. Shoemaker, and N. Yunes, Late Inspiral and Merger of Binary Black Holes in Scalar-Tensor Theories of Gravity, Class. Quant. Grav. 29, 232002 (2012), arXiv:1112.3928 [gr-qc]

  24. [32]

    Kanti, N

    P . Kanti, N. E. Mavromatos, J. Rizos, K. Tamvakis, and E. Winstanley, Dilatonic black holes in higher curvature string gravity, Phys. Rev. D 54, 5049 (1996), arXiv:hep-th/9511071

  25. [33]

    Torii, H

    T. Torii, H. Yajima, and K.-i. Maeda, Dilatonic black holes with Gauss-Bonnet term, Phys. Rev. D 55, 739 (1997), arXiv:gr-qc/9606034

  26. [34]

    T. P . Sotiriou and S.-Y. Zhou, Black hole hair in generalized scalar-tensor gravity, Phys. Rev. Lett.112, 251102 (2014), arXiv:1312.3622 [gr-qc]

  27. [35]

    D. D. Doneva and S. S. Yazadjiev, New Gauss-Bonnet Black Holes with Curvature-Induced Scalariza- tion in Extended Scalar-Tensor Theories, Phys. Rev. Lett.120, 131103 (2018), arXiv:1711.01187 [gr-qc]

  28. [36]

    H. O. Silva, J. Sakstein, L. Gualtieri, T. P . Sotiriou, and E. Berti, Spontaneous scalarization of black holes and compact stars from a Gauss-Bonnet coupling, Phys. Rev. Lett.120, 131104 (2018), arXiv:1711.02080 [gr-qc]

  29. [37]

    Antoniou, A

    G. Antoniou, A. Bakopoulos, and P . Kanti, Evasion of No-Hair Theorems and Novel Black-Hole Solu- tions in Gauss-Bonnet Theories, Phys. Rev. Lett. 120, 131102 (2018), arXiv:1711.03390 [hep-th]

  30. [38]

    Kleihaus, J

    B. Kleihaus, J. Kunz, S. Mojica, and E. Radu, Spinning black holes in Einstein–Gauss-Bonnet–dilaton theory: Nonperturbative solutions, Phys. Rev. D 93, 044047 (2016), arXiv:1511.05513 [gr-qc]

  31. [39]

    Kleihaus, J

    B. Kleihaus, J. Kunz, and E. Radu, Rotating Black Holes in Dilatonic Einstein-Gauss-Bonnet Theory, Phys. Rev. Lett. 106, 151104 (2011), arXiv:1101.2868 [gr-qc]

  32. [40]

    P . V . P . Cunha, C. A. R. Herdeiro, and E. Radu, Spontaneously Scalarized Kerr Black Holes in Extended Scalar-Tensor–Gauss-Bonnet Gravity, Phys. Rev. Lett.123, 011101 (2019), arXiv:1904.09997 [gr-qc]. 20

  33. [41]

    L. G. Collodel, B. Kleihaus, J. Kunz, and E. Berti, Spinning and excited black holes in Einstein-scalar- Gauss–Bonnet theory, Class. Quant. Grav. 37, 075018 (2020), arXiv:1912.05382 [gr-qc]

  34. [42]

    C. A. R. Herdeiro, E. Radu, H. O. Silva, T. P . Sotiriou, and N. Yunes, Spin-induced scalarized black holes, Phys. Rev. Lett. 126, 011103 (2021), arXiv:2009.03904 [gr-qc]

  35. [43]

    Berti, L

    E. Berti, L. G. Collodel, B. Kleihaus, and J. Kunz, Spin-induced black-hole scalarization in Einstein- scalar-Gauss-Bonnet theory, Phys. Rev. Lett. 126, 011104 (2021), arXiv:2009.03905 [gr-qc]

  36. [44]

    J. L. Ripley and F. Pretorius, Scalarized Black Hole dynamics in Einstein dilaton Gauss-Bonnet Gravity, Phys. Rev. D 101, 044015 (2020), arXiv:1911.11027 [gr-qc]

  37. [45]

    W. E. East and J. L. Ripley, Evolution of Einstein-scalar-Gauss-Bonnet gravity using a modified har- monic formulation, Phys. Rev. D 103, 044040 (2021), arXiv:2011.03547 [gr-qc]

  38. [46]

    D. D. Doneva, L. Arest ´e Sal ´o, and S. S. Yazadjiev, 3+1 nonlinear evolution of Ricci-coupled scalar- Gauss-Bonnet gravity, Phys. Rev. D 110, 024040 (2024), arXiv:2404.15526 [gr-qc]

  39. [47]

    D. D. Doneva, L. Arest ´e Sal ´o, K. Clough, P . Figueras, and S. S. Yazadjiev, Testing the limits of scalar- Gauss-Bonnet gravity through nonlinear evolutions of spin-induced scalarization, Phys. Rev. D 108, 084017 (2023), arXiv:2307.06474 [gr-qc]

  40. [48]

    Thaalba, N

    F. Thaalba, N. Franchini, M. Bezares, and T. P . Sotiriou, Hyperbolicity in scalar-Gauss-Bonnet gravity: A gauge invariant study for spherical evolution, Phys. Rev. D 111, 024053 (2025), arXiv:2410.16264 [gr-qc]

  41. [49]

    Thaalba, N

    F. Thaalba, N. Franchini, M. Bezares, and T. P . Sotiriou, Dynamics of spherically symmetric black holes in scalar-Gauss-Bonnet gravity with a Ricci coupling, Phys. Rev. D111, 064054 (2025), arXiv:2409.11398 [gr-qc]

  42. [50]

    Thaalba, M

    F. Thaalba, M. Bezares, N. Franchini, and T. P . Sotiriou, Spherical collapse in scalar-Gauss-Bonnet grav- ity: Taming ill-posedness with a Ricci coupling, Phys. Rev. D 109, L041503 (2024), arXiv:2306.01695 [gr-qc]

  43. [51]

    Franchini, M

    N. Franchini, M. Bezares, E. Barausse, and L. Lehner, Fixing the dynamical evolution in scalar-Gauss- Bonnet gravity, Phys. Rev. D 106, 064061 (2022), arXiv:2206.00014 [gr-qc]

  44. [52]

    W. E. East and J. L. Ripley, Dynamics of Spontaneous Black Hole Scalarization and Mergers in Einstein- Scalar-Gauss-Bonnet Gravity, Phys. Rev. Lett. 127, 101102 (2021), arXiv:2105.08571 [gr-qc]

  45. [53]

    Corman and W

    M. Corman and W. E. East, Black hole-neutron star mergers in Einstein-scalar-Gauss-Bonnet gravity, Phys. Rev. D 110, 084065 (2024), arXiv:2405.18496 [gr-qc]

  46. [54]

    W. E. East and F. Pretorius, Binary neutron star mergers in Einstein-scalar-Gauss-Bonnet gravity, Phys. Rev. D 106, 104055 (2022), arXiv:2208.09488 [gr-qc]

  47. [55]

    Corman, J

    M. Corman, J. L. Ripley, and W. E. East, Nonlinear studies of binary black hole mergers in Einstein- scalar-Gauss-Bonnet gravity, Phys. Rev. D 107, 024014 (2023), arXiv:2210.09235 [gr-qc]

  48. [56]

    Corman, L

    M. Corman, L. Lehner, W. E. East, and G. Dideron, Nonlinear studies of modifications to general relativity: Comparing different approaches, Phys. Rev. D 110, 084048 (2024), arXiv:2405.15581 [gr-qc]

  49. [57]

    A. H. K. R, J. L. Ripley, and N. Yunes, Where and why does Einstein-scalar-Gauss-Bonnet theory break down?, Phys. Rev. D 107, 044044 (2023), arXiv:2211.08477 [gr-qc]

  50. [58]

    Okounkova, L

    M. Okounkova, L. C. Stein, M. A. Scheel, and D. A. Hemberger, Numerical binary black hole mergers in dynamical Chern-Simons gravity: Scalar field, Phys. Rev. D 96, 044020 (2017), arXiv:1705.07924 [gr-qc]

  51. [59]

    H. O. Silva, H. Witek, M. Elley, and N. Yunes, Dynamical Descalarization in Binary Black Hole Merg- ers, Phys. Rev. Lett. 127, 031101 (2021), arXiv:2012.10436 [gr-qc]

  52. [60]

    Elley, H

    M. Elley, H. O. Silva, H. Witek, and N. Yunes, Spin-induced dynamical scalarization, descalarization, and stealthness in scalar-Gauss-Bonnet gravity during a black hole coalescence, Phys. Rev. D 106, 044018 (2022), arXiv:2205.06240 [gr-qc]

  53. [61]

    D. D. Doneva, A. Va ˜n´o Vi˜nuales, and S. S. Yazadjiev, Dynamical descalarization with a jump during a black hole merger, Phys. Rev. D 106, L061502 (2022), arXiv:2204.05333 [gr-qc]

  54. [62]

    Evstafyeva, M

    T. Evstafyeva, M. Agathos, and J. L. Ripley, Measuring the ringdown scalar polarization of 21 gravitational waves in Einstein-scalar-Gauss-Bonnet gravity, Phys. Rev. D 107, 124010 (2023), arXiv:2212.11359 [gr-qc]

  55. [63]

    Shiralilou, T

    B. Shiralilou, T. Hinderer, S. Nissanke, N. Ortiz, and H. Witek, Nonlinear curvature effects in gravita- tional waves from inspiralling black hole binaries, Phys. Rev. D103, L121503 (2021), arXiv:2012.09162 [gr-qc]

  56. [64]

    Shiralilou, T

    B. Shiralilou, T. Hinderer, S. M. Nissanke, N. Ortiz, and H. Witek, Post-Newtonian gravitational and scalar waves in scalar-Gauss–Bonnet gravity, Class. Quant. Grav. 39, 035002 (2022), arXiv:2105.13972 [gr-qc]

  57. [65]

    Juli ´e and E

    F.-L. Juli ´e and E. Berti, Post-Newtonian dynamics and black hole thermodynamics in Einstein-scalar- Gauss-Bonnet gravity, Phys. Rev. D 100, 104061 (2019), arXiv:1909.05258 [gr-qc]

  58. [66]

    K. Yagi, L. C. Stein, N. Yunes, and T. Tanaka, Post-Newtonian, Quasi-Circular Binary Inspirals in Quadratic Modified Gravity, Phys. Rev. D 85, 064022 (2012), [Erratum: Phys.Rev.D 93, 029902 (2016)], arXiv:1110.5950 [gr-qc]

  59. [67]

    Z. Lyu, N. Jiang, and K. Yagi, Constraints on Einstein-dilation-Gauss-Bonnet gravity from black hole- neutron star gravitational wave events, Phys. Rev. D 105, 064001 (2022), [Erratum: Phys.Rev.D 106, 069901 (2022), Erratum: Phys.Rev.D 106, 069901 (2022)], arXiv:2201.02543 [gr-qc]

  60. [68]

    Lara et al

    G. Lara et al. , Signatures from metastable oppositely-charged black hole binaries in scalar Gauss- Bonnet gravity, (2025), arXiv:2505.14785 [gr-qc]

  61. [69]

    S. E. Brady, L. Arest ´e Sal´o, K. Clough, P . Figueras, and A. P . S., Solving the initial conditions problem for modified gravity theories, Phys. Rev. D 108, 104022 (2023), arXiv:2308.16791 [gr-qc]

  62. [70]

    P . J. Nee, G. Lara, H. P . Pfeiffer, and N. L. Vu, Quasistationary hair for binary black hole initial data in scalar Gauss-Bonnet gravity, Phys. Rev. D 111, 024061 (2025), arXiv:2406.08410 [gr-qc]

  63. [71]

    R. M. Wald, General Relativity (Chicago Univ. Pr., Chicago, USA, 1984)

  64. [72]

    D. Alic, C. Bona-Casas, C. Bona, L. Rezzolla, and C. Palenzuela, Conformal and covariant formulation of the Z4 system with constraint-violation damping, Phys. Rev. D 85, 064040 (2012), arXiv:1106.2254 [gr-qc]

  65. [73]

    Arest ´e Sal ´o, S

    L. Arest ´e Sal ´o, S. E. Brady, K. Clough, D. Doneva, T. Evstafyeva, P . Figueras, T. Franc ¸a, L. Rossi, and S. Yao, GRFolres: A code for modified gravity simulations in strong gravity, J. Open Source Softw. 9, 6369 (2024), arXiv:2309.06225 [gr-qc]

  66. [74]

    Andrade et al., GRChombo: An adaptable numerical relativity code for fundamental physics, J

    T. Andrade et al., GRChombo: An adaptable numerical relativity code for fundamental physics, J. Open Source Softw. 6, 3703 (2021), arXiv:2201.03458 [gr-qc]

  67. [75]

    Radia, U

    M. Radia, U. Sperhake, A. Drew, K. Clough, P . Figueras, E. A. Lim, J. L. Ripley, J. C. Aurrekoetxea, T. Franc ¸a, and T. Helfer, Lessons for adaptive mesh refinement in numerical relativity, Class. Quant. Grav. 39, 135006 (2022), arXiv:2112.10567 [gr-qc]

  68. [76]

    Ansorg, B

    M. Ansorg, B. Br ¨ugmann, and W. Tichy, A Single-domain spectral method for black hole puncture data, Phys. Rev. D 70, 064011 (2004), arXiv:gr-qc/0404056

  69. [77]

    Br ¨ugmann, J

    B. Br ¨ugmann, J. A. Gonz´alez, M. Hannam, S. Husa, U. Sperhake, and W. Tichy, Calibration of Moving Puncture Simulations, Phys. Rev. D 77, 024027 (2008), arXiv:gr-qc/0610128

  70. [78]

    Ferguson et al

    D. Ferguson et al. , Second MAYA Catalog of Binary Black Hole Numerical Relativity Waveforms, (2023), arXiv:2309.00262 [gr-qc]

  71. [79]

    Witek, L

    H. Witek, L. Gualtieri, and P . Pani, Towards numerical relativity in scalar Gauss-Bonnet gravity: 3+ 1 decomposition beyond the small-coupling limit, Phys. Rev. D 101, 124055 (2020), arXiv:2004.00009 [gr-qc]

  72. [80]

    Sennett, S

    N. Sennett, S. Marsat, and A. Buonanno, Gravitational waveforms in scalar-tensor gravity at 2PN relative order, Phys. Rev. D 94, 084003 (2016), arXiv:1607.01420 [gr-qc]

  73. [81]

    P . Y. Yordanov, K. V . Staykov, S. S. Yazadjiev, and D. D. Doneva, The power of binary pulsars in testing Gauss-Bonnet gravity, Astron. Astrophys. 687, A17 (2024), arXiv:2402.06305 [gr-qc]

  74. [82]

    M ¨uller, J

    D. M ¨uller, J. Grigsby, and B. Br¨ugmann, Dynamical shift condition for unequal mass black hole bina- ries, Phys. Rev. D 82, 064004 (2010), arXiv:1003.4681 [gr-qc]. 22

  75. [83]

    Arest ´e Sal´o, M

    L. Arest ´e Sal´o, M. Corman, and K. Clough, GH3d2M versus GRFolres, in preparation, (2025)

  76. [84]

    Witek, L

    H. Witek, L. Gualtieri, P . Pani, and T. P . Sotiriou, Black holes and binary mergers in scalar Gauss- Bonnet gravity: scalar field dynamics, Phys. Rev. D 99, 064035 (2019), arXiv:1810.05177 [gr-qc]

  77. [85]

    A. K.-W. Chung and N. Yunes, Quasinormal mode frequencies and gravitational perturbations of black holes with any subextremal spin in modified gravity through METRICS: The scalar-Gauss- Bonnet gravity case, Phys. Rev. D 110, 064019 (2024), arXiv:2406.11986 [gr-qc]

  78. [86]

    F. S. Khoo, J. L. Bl ´azquez-Salcedo, B. Kleihaus, and J. Kunz, Quasinormal modes of rotating black holes in shift-symmetric Einstein-scalar-Gauss-Bonnet theory, (2024), arXiv:2412.09377 [gr-qc]

  79. [87]

    M. H.-Y. Cheung, E. Berti, V . Baibhav, and R. Cotesta, Extracting linear and nonlinear quasinormal modes from black hole merger simulations, Phys. Rev. D 109, 044069 (2024), [Erratum: Phys.Rev.D 110, 049902 (2024)], arXiv:2310.04489 [gr-qc]

  80. [88]

    H. P . Pfeiffer, D. A. Brown, L. E. Kidder, L. Lindblom, G. Lovelace, and M. A. Scheel, Reducing orbital eccentricity in binary black hole simulations, Class. Quant. Grav. 24, S59 (2007), arXiv:gr-qc/0702106

  81. [89]

    A. H. Mroue, H. P . Pfeiffer, L. E. Kidder, and S. A. Teukolsky, Measuring orbital eccentricity and perias- tron advance in quasi-circular black hole simulations, Phys. Rev. D 82, 124016 (2010), arXiv:1004.4697 [gr-qc]

Pith tools

Reviewed August 6, 2026 · model on record in the stance chip above.