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Stationary scalar clouds around a rotating BTZ-like black hole in the Einstein-bumblebee gravity

T0 review · 2 major / 5 minor · reviewed 2026-08-10 · deepseek-v4-flash

Pith's one-line read Rotating BTZ-like black holes in bumblebee gravity support nodeless scalar clouds.

desk verdict Clean extension of BTZ scalar clouds to Einstein-bumblebee gravity with a genuinely new degenerate-cloud observation; the 'only n=0 cloud' claim is numerically supported but not proven. read the letter →

arxiv 2501.15759 v1 pith:WZ7HUZMB submitted 2025-01-27 gr-qc hep-th

classification gr-qchep-th PACS 04.70.-s04.70.Bw97.60.Lf
keywords stationaryscalarcloudsbumblebeegravityBTZblackholeLorentzsymmetrybreakingRobinboundaryconditionssuperradiancequasinormalmodesAdS3
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

This paper establishes that rotating BTZ-like black holes in Einstein-bumblebee gravity—a three-dimensional theory with spontaneous Lorentz symmetry breaking—can support stationary scalar clouds, provided the scalar field is tachyonic (µ²<0) and obeys Robin rather than Dirichlet boundary conditions at the AdS boundary. By scanning the parameter space, the authors find that only the nodeless (n=0) mode forms these clouds, and that the Lorentz-breaking parameter s and the angular quantum number k shift the existence lines in opposite directions: increasing s lowers the black-hole mass at which a cloud exists, while increasing k raises it. Certain pairs (k,s) produce identical existence lines, which the paper calls degenerate clouds, even though their radial profiles differ. The result matters because it shows that Lorentz violation enriches the possible hair of rotating black holes and could help distinguish bumblebee gravity from ordinary Einstein gravity.

What carries the argument

The argument rests on reducing the massive Klein-Gordon equation on the BTZ-like background to a hypergeometric equation via the radial coordinate z=(r²-r+²)/(r²-r-²). The general solution at infinity is a linear combination of Dirichlet and Neumann solutions, and the requirement of vanishing energy flux at the AdS boundary imposes a Robin boundary condition φ=cos(ζ)φ_D+sin(ζ)φ_N. Substituting the resonance condition ω=kΩ_H into this boundary condition yields a single transcendental equation (Eq. 25) whose solutions give the existence lines of scalar clouds. The paper scans this equation numerically, together with the quasinormal-mode condition (Eq. 27), to map out the allowed parameter space and identify the superradiant instability thresholds.

What would settle it

Solve the cloud existence condition (Eq. 25) with a non-tachyonic scalar mass (µ²>0) while keeping the Robin parameter and s in the allowed range; if any nodeless cloud solution appears, the claim that clouds require µ²<0 is false. Alternatively, impose the pure Dirichlet boundary condition (ζ=0) and search for stationary clouds: the paper predicts none, so finding one would falsify the central claim.

Watch

Extended reading notes

Core claim

The central claim is that in Einstein-bumblebee gravity, a non-extremal rotating BTZ-like black hole can support stationary, fundamental (n=0) scalar clouds when the massive scalar field satisfies Robin boundary conditions at the AdS boundary, with the Lorentz-breaking parameter s and scalar mass µ satisfying -1 < s < -(1+1/µ²) and µ²<0. The existence lines—curves in the black-hole mass versus horizon angular velocity plane—are obtained by imposing the resonance condition ω=kΩ_H, which turns the Robin boundary condition into a transcendental equation. The paper shows that increasing s shifts these curves toward smaller masses, increasing k shifts them toward larger masses, and that for special choices such as (k=1,s=0), (k=2,s=0.36794), (k=3,s=0.42830), (k=4,s=0.45342) the curves coincide, giving degenerate clouds with different radial profiles. The authors also show that the Lorentz-breaking parameter does not affect the superradiance condition, that superradiant instabilities appear only for the nodeless mode of type L, and that extremal BTZ-like black holes support no such clouds.

Load-bearing premise

The existence of the clouds depends on choosing Robin boundary conditions with a fixed ζ, a tachyonic scalar mass µ²<0, and s in the range -1 < s < -(1+1/µ²); these are input choices, not consequences of the bumblebee model, and pure Dirichlet conditions would eliminate the clouds.

Editorial extensions

If this is right

  • If correct, bumblebee gravity predicts a family of stationary scalar clouds around rotating BTZ-like black holes, with only the nodeless mode supported.
  • The opposite effects of s and k mean that measuring or computing cloud existence lines can, in principle, constrain the Lorentz-breaking parameter relative to the scalar angular quantum number.
  • Superradiant instabilities occur only for nodeless modes, so these clouds sit exactly at the threshold of instability; this ties cloud existence to the onset of superradiance.
  • Degenerate clouds sharing the same existence line but differing in radial profile provide a way to distinguish bumblebee gravity from Einstein gravity even when the existence lines coincide.
  • Extremal BTZ-like black holes do not support clouds, focusing observational or holographic searches on the non-extremal sector.

Reading between the lines

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

  • The existence of degenerate clouds hints at a hidden identity or mapping between the Lorentz-breaking parameter s and the angular quantum number k encoded in Eq. (25); exploring this analytically could reveal a symmetry of the bumblebee BTZ system not mentioned in the paper.
  • Because pure Dirichlet conditions eliminate the clouds, the result is boundary-condition sensitive; a similar analysis with other boundary conditions (e.g., a different Robin parameter ζ) may yield a continuous family of existence lines rather than isolated curves.
  • The finding that superradiant instabilities appear only for n=0 may be a general feature of three-dimensional rotating AdS black holes with Robin boundary conditions, and could be tested in other modified-gravity backgrounds.
  • The parameter bound s < -(1+1/µ²) implies that for a fixed tachyonic mass, Lorentz breaking cannot be arbitrarily large; if clouds are ever observed, this would give a direct upper bound on |s|.
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Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

2 major / 5 minor

Summary. This paper studies stationary scalar clouds of a massive scalar field around a rotating BTZ-like black hole in Einstein-bumblebee gravity. The authors reduce the massive Klein-Gordon equation to a hypergeometric equation, impose an ingoing boundary condition at the horizon and a Robin boundary condition at the AdS boundary, and derive the cloud existence condition Eq. (25) and the quasinormal-mode equation Eq. (27). By numerically scanning the parameter space they find fundamental (n=0) clouds, observe that the Lorentz-breaking parameter s and the angular quantum number k have opposite effects on the existence lines, identify degenerate clouds for specific (k,s) pairs, and check that the threshold of the superradiant instability matches the cloud condition. The analysis is largely analytic and self-contained, but the generality of the 'only n=0' conclusion is not supported by the presented numerical evidence.

Significance. The clean reduction of the radial problem to a hypergeometric equation and the explicit matching condition make the computation of the fundamental cloud branch straightforward and reproducible. The observation that s and k have opposite effects, and the existence of degenerate (k,s) pairs with identical existence lines, are interesting and potentially useful for distinguishing Lorentz-violating black holes from standard BTZ metrics. The consistency between the superradiant zero-mode threshold and the cloud condition is a valuable check. However, the paper's central qualitative claim that superradiant instabilities and clouds exist only for the n=0 modes rests on a single numerical configuration and therefore needs either an analytic argument or a restricted statement.

major comments (2)
  1. [Section IV, Figs. 5-6] The claim that superradiant instabilities appear only for the n=0, type-L modes, and hence that only fundamental stationary clouds exist, is supported only by numerical solutions of Eq. (27) for the single configuration r_+=5, r_-=3, ℓ=1, k=1, µ^2=-0.65, with s varied. No scan over k, the ratio r_-/r_+, or µ^2 is presented, and no analytic argument (such as a monotonicity or asymptotic bound on the Gamma-function ratio in Eq. (27)) is given. Because the Abstract and Conclusions state this 'only n=0' result as a general property and use it to contrast with the Kerr case, this gap is load-bearing. The authors should either restrict the claim to the parameter range actually scanned, or provide an analytic proof or a systematic numerical scan over the parameter space.
  2. [Section III, Eq. (25), Figs. 1-3] The paper does not establish that Eq. (25) has a unique solution for r_+ at fixed (k, s, ζ, µ^2). The equation is transcendental in r_+ through the variable x = k ℓ sqrt(1+s) / (2 r_+), and the figures plot the resulting existence lines without a proof that no additional branches exist. Since the conclusion that only nodeless clouds are supported relies on the absence of other cloud branches, a uniqueness or monotonicity analysis of the right-hand side of Eq. (25) (or an explicit demonstration that all solutions are captured by the plotted curves) is needed.
minor comments (5)
  1. [Throughout] There are several typographical errors, including 'h ole' in the title, 'Thererfore' in Appendix A, and 'valves' for 'values' near the end of Section IV; these should be corrected.
  2. [Section IV, Fig. 5] The mode labels such as '0,L' and '1,L' in Fig. 5 are not defined in the text; please define the notation for the overtone number and the L/R (left/right-moving) type explicitly.
  3. [Section IV, Eq. (27)] The numerical procedure for solving Eq. (27) is not described; a brief account of the root-finding method, mode classification, and accuracy checks would improve reproducibility.
  4. [Section IV, Fig. 6] The curve labeled s=sapp=0.53846 coincides with the upper bound of Eq. (19), for which the parameter q = sqrt(1+µ^2(1+s)) vanishes; please clarify that this is a limiting case and that the strict inequality required by Eq. (19) is maintained for all physical configurations.
  5. [Conclusions, paragraph 2] The statement that 'there exist infinite degenerate clouds for any initial values of s and k' is an extrapolation from the four pairs shown in Fig. 3; the authors should either prove the existence of the limiting sequence or soften this claim.

Circularity Check

0 steps flagged · score 1.0 of 10

No significant circularity: cloud existence lines are direct solutions of the explicit transcendental condition (25), and the QNM zero-mode check is a consistency check, not a reuse of the target result.

full rationale

The paper's central derivation is self-contained: the stationary cloud condition Eq. (25) follows from the explicit hypergeometric solution of the Klein-Gordon equation, the ingoing condition at the horizon, and the Robin boundary condition at infinity, with no parameter fitted to the cloud data. The existence lines in Figs. 1-3 are direct numerical solutions of this transcendental equation for chosen input parameters (μ²=-0.65, ζ=0.9π, ℓ=1), not predictions extracted from a fit. The quasinormal-mode analysis in Section IV solves the independent condition Eq. (27); the observation that its superradiant zero-mode threshold coincides with Eq. (25) is mathematically expected because setting ω=ωc and Im[ω]=0 reduces Eq. (27) to Eq. (25), so it functions as a consistency check rather than as the origin of the cloud claim. Self-citations (Refs. [37,49,50]) provide background and comparisons and are not load-bearing for the derivation. The skeptic's concern that the 'only n=0' generalization rests on a single QNM configuration (r+=5, r-=3, k=1) is a legitimate completeness/rigor issue, not a circularity issue: it questions the breadth of the numerical evidence, not whether the result is assumed as an input.

Assumptions & free parameters 2 free parameters · 4 assumptions · 0 invented entities

The central claims are established by scanning the parameter space (µ², ζ, s, k, M, Ω_H). The only hand-chosen inputs are the reference values µ²=-0.65 and ζ=0.9π; the geometry and the test-field treatment are inherited from the bumblebee literature. No new particles, forces, or fitted constants are introduced.

free parameters (2)
  • µ² (scalar mass squared) = -0.65
    Chosen by hand as a representative value inside the square-integrability window of Eq. (19); all existence line and QNM plots use this value.
  • ζ (Robin boundary parameter) = 0.9π
    Chosen as a representative boundary condition in the allowed range [ζ*, π) for the cloud plots; Fig. 6 later maps the stability threshold range 0.5π < ζ < 0.75π for one configuration.
assumptions (4)
  • domain assumption The rotating BTZ-like metric (2) is an exact solution of the Einstein-bumblebee field equations.
    Taken from Ref. [48]; the present paper does not derive it.
  • domain assumption The scalar field is a test field, and the bumblebee field remains frozen at its vacuum expectation value, so the only remnant of Lorentz violation is the constant s in the metric.
    The action (1) and solution (2) are adopted; the paper does not include backreaction.
  • ad hoc to paper The Robin boundary condition (21) with a fixed ζ, together with the square-integrability requirement (19), selects the physical modes.
    The existence of clouds depends on this input; different boundary conditions (e.g., pure Dirichlet) would remove them. It follows Refs. [15,16] rather than being derived from the theory.
  • standard math The resonance condition ω = kΩ_H (Eq. 23) marks the superradiant threshold and hence the cloud locus.
    Standard superradiance theory, cited from Ref. [69]; used to set α=0 in the hypergeometric solution.

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Cite this review

Pith. "Pith review of Stationary scalar clouds around a rotating BTZ-like black hole in the Einstein-bumblebee gravity." pith.science (2026). https://pith.science/paper/WZ7HUZMB

@misc{pith2026250115759,
  author       = {Pith},
  title        = {Pith review of: Stationary scalar clouds around a rotating BTZ-like black hole in the Einstein-bumblebee gravity},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/WZ7HUZMB}},
  note         = {Machine review of arXiv:2501.15759}
}
abstract

We have studied stationary clouds of massive scalar fields around a rotating BTZ-like black hole in the Einstein-bumblebee gravity, by imposing the Robin type boundary conditions at the AdS boundary. We establish, by scanning the parameter space, the existence of \textit{fundamental} stationary scalar clouds ($i.e.$, the overtone number $n=0$). In particular, we observe that the Lorentz symmetry breaking parameter $s$ and the quantum number $k$ play an opposite role in determining scalar clouds, which indicates the existence of \textit{degenerate} scalar clouds. To illustrate the fact that scalar clouds may only be supported for the $n=0$ case, we have analyzed the impact of various parameters on scalar quasinormal modes. It is shown that the Lorentz symmetry breaking parameter $s$ does not change the superradiance condition, and superradiant instabilities only appear for the fundamental modes. Our work shows that the Lorentz symmetry breaking provides richer physics in stationary scalar clouds around black holes.

Figures

Figures reproduced from arXiv: 2501.15759 by the authors.

Figure 1
Figure 1. FIG. 1. Existence lines of nodeless scalar clouds ( [PITH_FULL_IMAGE:figures/full_fig_p008_1.png] view at source ↗
Figure 2
Figure 2. FIG. 2. Existence lines of nodeless scalar clouds ( [PITH_FULL_IMAGE:figures/full_fig_p009_2.png] view at source ↗
Figure 3
Figure 3. FIG. 3. Degenerate existence lines of nodeless scalar cloud [PITH_FULL_IMAGE:figures/full_fig_p009_3.png] view at source ↗
Figures from the paper (3 more)
Figure 4
Figure 4. Figure 4: FIG. 4. The radial profile of degenerate clouds on BTZ-like bl [PITH_FULL_IMAGE:figures/full_fig_p010_4.png]
Figure 5
Figure 5. Figure 5: FIG. 5. Imaginary parts of some quasinormal frequencies as a [PITH_FULL_IMAGE:figures/full_fig_p011_5.png]
Figure 6
Figure 6. Figure 6: FIG. 6. Imaginary parts of some quasinormal frequencies of n [PITH_FULL_IMAGE:figures/full_fig_p013_6.png]

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Forward citations

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Works this paper leans on

69 extracted references · 45 canonical work pages · cited by 2 Pith papers

  1. [1]

    Ruffini and J.A

    R. Ruffini and J.A. Wheeler, Phys. Today 24, 30 (1971)

  2. [2]

    Carter, in Black Holes, Proceedings of 1972 Session of Ecole d’ete de Physique Theorique, edited by C

    B. Carter, in Black Holes, Proceedings of 1972 Session of Ecole d’ete de Physique Theorique, edited by C. De Witt and B.S. De Witt (Gordon and Breach, New York, 1973)

  3. [3]

    Misner, K.S

    C.W. Misner, K.S. Thorne, and J.A. Wheeler, Gravitation (Freeman, San Francisco, 1973)

  4. [4]

    Hod, Stationary scalar clouds around rotating black holes , Phys

    S. Hod, Stationary scalar clouds around rotating black holes , Phys. Rev. D 86, 104026 (2012); 86, 129902(E) (2012)

  5. [5]

    Hod, Stationary resonances of rapidly-rotating Kerr black hole s, Eur

    S. Hod, Stationary resonances of rapidly-rotating Kerr black hole s, Eur. Phys. J. C 73, 2378 (2013); arXiv:1311.5298 [gr-qc]

  6. [6]

    Hod, Kerr-Newman black holes with stationary charged scalar clo uds, Phys

    S. Hod, Kerr-Newman black holes with stationary charged scalar clo uds, Phys. Rev. D 90, 024051 (2014)

  7. [7]

    Hod, Analytic treatment of the system of a Kerr-Newman black hole and a charged massive scalar field , Phys

    S. Hod, Analytic treatment of the system of a Kerr-Newman black hole and a charged massive scalar field , Phys. Rev. D 94, 044036 (2016)

  8. [8]

    Herdeiro and E

    C. Herdeiro and E. Radu, Kerr black holes with scalar hair , Phys. Rev. Lett. 112, 221101 (2014); arXiv:1403.2757 [gr-qc]

Show all 69 references
  1. [9]

    Benone, L.C.B

    C.L. Benone, L.C.B. Crispino, C. Herdeiro, and E. Radu, Kerr-Newman scalar clouds , Phys. Rev. D 90, 104024 (2014)

  2. [10]

    Herdeiro and E

    C. Herdeiro and E. Radu, Construction and physical properties of Kerr black holes wi th scalar hair , Class. Quant. Grav. 32, 144001 (2015); arXiv:1501.04319 [gr-qc]

  3. [11]

    Herdeiro, E

    C. Herdeiro, E. Radu, and H. R´ unarsson, Kerr black holes with self-interacting scalar hair: Hairie r but not heavier , Phys. Rev. D 92, 084059 (2015)

  4. [12]

    Sampaio, C

    M. Sampaio, C. Herdeiro, and M. Wang, Marginal scalar and Proca clouds around Reissner-Nordstr¨om black holes , Phys. Rev. D 90, 064004 (2014)

  5. [13]

    Wang and C

    M. Wang and C. Herdeiro, Maxwell perturbations on Kerr-anti-de Sitter black holes: Quasinormal modes, super- radiant instabilities, and vector clouds , Phys. Rev. D 93, 064066 (2016)

  6. [14]

    Wang, Y.X

    Y.Q. Wang, Y.X. Liu, and S.W. Wei, Excited Kerr black holes with scalar hair , Phys. Rev. D 99, 064036 (2019); arXiv:1811.08795 [gr-qc]

  7. [15]

    Ferreira and C.A.R

    H.R.C. Ferreira and C.A.R. Herdeiro, Stationary scalar clouds around a BTZ black hole , Phys. Lett. B 773, 129 (2017); arXiv:1707.08133 [gr-qc]

  8. [16]

    Dappiaggi, H.R.C

    C. Dappiaggi, H.R.C. Ferreira, and C.A.R. Herdeiro, Superradiance in the BTZ black hole with Robin boundary conditions, Phys. Lett. B 778, 146 (2018); arXiv:1710.08039 [gr-qc]

  9. [17]

    Herdeiro, E

    C. Herdeiro, E. Radu, and H. R´ unarsson, Non-linear Q-clouds around Kerr black holes , Phys. Lett. B 739, 302 (2014)

  10. [18]

    Okawa, Nonlinear evolutions of bosonic clouds around black holes , Class

    H. Okawa, Nonlinear evolutions of bosonic clouds around black holes , Class. Quant. Grav. 32, 214003 (2015)

  11. [19]

    Huang and D.J

    Y. Huang and D.J. Liu, Scalar clouds and the superradiant instability regime of Ke rr-Newman black hole , Phys. Rev. D 94, 064030 (2016)

  12. [20]

    Hod, Spinning Kerr black holes with stationary massive scalar cl ouds: the large-coupling regime , J

    S. Hod, Spinning Kerr black holes with stationary massive scalar cl ouds: the large-coupling regime , J. High Energ. Phys. 01, 030 (2017); arXiv:1612.00014 [hep-th]

  13. [21]

    Garc ´ ıa and M

    G. Garc ´ ıa and M. Salgado,Obstructions towards a generalization of no-hair theorems : Scalar clouds around Kerr black holes , Phys. Rev. D 99, 044036 (2019)

  14. [22]

    Hod, Analytic treatment of near-extremal charged black holes su pporting non-minimally coupled massless scalar clouds, Eur

    S. Hod, Analytic treatment of near-extremal charged black holes su pporting non-minimally coupled massless scalar clouds, Eur. Phys. J. C 80, 1150 (2020)

  15. [23]

    Liu, G.H

    S.P. Liu, G.H. Liu, and Y. Peng, Stationary scalar clouds outside charged reflecting compac t stars , Mod. Phys. Lett. A 35, 2050175 (2020)

  16. [24]

    Garc ´ ıa and M

    G. Garc ´ ıa and M. Salgado, Existence or absence of superregular boson clouds around ex tremal Kerr black holes and its connection with number theory , Phys. Rev. D 101, 044040 (2020)

  17. [25]

    Garc ´ ıa and M

    G. Garc ´ ıa and M. Salgado, Regular scalar charged clouds around a Reissner-Nordstr¨ o m black hole and no-hair theorems, Phys. Rev. D 104, 064054 (2021). 16

  18. [26]

    Hod, Nonequatorial scalar clouds supported by maximally spinni ng Kerr black holes , Phys

    S. Hod, Nonequatorial scalar clouds supported by maximally spinni ng Kerr black holes , Phys. Rev. D 108, 124028 (2023)

  19. [27]

    Garc ´ ıa and M

    G. Garc ´ ıa and M. Salgado, Regular scalar clouds around a Kerr-Newman black hole: Sube xtremal and extremal scenarios, Phys. Rev. D 108, 104012 (2023)

  20. [28]

    Hod, Spatially regular charged black holes supporting charged m assive scalar clouds , Phys

    S. Hod, Spatially regular charged black holes supporting charged m assive scalar clouds , Phys. Rev. D 109, 064074 (2024)

  21. [29]

    G.Z. Guo, P. Wang, T.S. Wu, and H.T. Yang, Stationary Scalar Clouds around Kerr-Newman Black Holes , arXiv:2408.09243 [gr-qc]

  22. [30]

    R. Li, J.K. Zhao, X.H. Wu, and Y.M. Zhang, Scalar clouds in charged stringy black hole-mirror system , Eur. Phys. J. C 75, 142 (2015)

  23. [31]

    Benone, L.C.B

    C.L. Benone, L.C.B. Crispino, C. Herdeiro, and E. Radu, Acoustic clouds: Standing sound waves around a black hole analogue, Phys. Rev. D 91, 104038 (2015)

  24. [32]

    Radu, D.H

    E. Radu, D.H. Tchrakian, and Y.S. Yang, Non-Abelian clouds around Reissner-Nordstr¨ om black holes: The exis- tence line , Phys. Rev. D 93, 124069 (2016)

  25. [33]

    Bernard, Stationary charged scalar clouds around black holes in stri ng theory, Phys

    C. Bernard, Stationary charged scalar clouds around black holes in stri ng theory, Phys. Rev. D 94, 085007 (2016)

  26. [34]

    Huang, D.J

    Y. Huang, D.J. Liu, X.H. Zhai, and X.Z. Li, Scalar clouds around Kerr-Sen black holes , Class. Quant. Grav. 34, 155002 (2017)

  27. [35]

    Tokgoz and I

    G. Tokgoz and I. Sakalli, Stationary scalar clouds around maximally rotating linear dilaton black holes , Class. Quant. Grav. 34, 125007 (2017)

  28. [36]

    Grandi and I.S

    N. Grandi and I.S. Landea, Scalar hair around charged black holes in Einstein-Gauss-B onnet gravity , Phys. Rev. D 97, 044042 (2018)

  29. [37]

    X. Qiao, M. Wang, Q. Pan, and J. Jing, Kerr-MOG black holes with stationary scalar clouds , Eur. Phys. J. C 80, 509 (2020)

  30. [38]

    Hod, Stationary scalar clouds supported by rapidly-rotating ac oustic black holes in a photon-fluid model , Phys

    S. Hod, Stationary scalar clouds supported by rapidly-rotating ac oustic black holes in a photon-fluid model , Phys. Rev. D 103, 084003 (2021)

  31. [39]

    Ciszak and F

    M. Ciszak and F. Marino, Acoustic black-hole bombs and scalar clouds in a photon-flui d model , Phys. Rev. D 103, 045004 (2021)

  32. [40]

    Huang and H.S

    Y. Huang and H.S. Zhang, True gravitational atoms: Spherical cloud of dilatonic bla ck holes , Phys. Rev. D 105, 124056 (2022)

  33. [41]

    Siqueira and M

    P.H.C. Siqueira and M. Richartz, Quasinormal modes, quasibound states, scalar clouds, and s uperradiant instabil- ities of a Kerr-like black hole , Phys. Rev. D 106, 024046 (2022)

  34. [42]

    Zhang, Nonlinear instability and scalar clouds of spherical exoti c compact objects in scalar-Gauss-Bonnet theory, Eur

    S.J. Zhang, Nonlinear instability and scalar clouds of spherical exoti c compact objects in scalar-Gauss-Bonnet theory, Eur. Phys. J. C 83, 950 (2023)

  35. [43]

    Hod, Charged Gauss-Bonnet black holes supporting non-minimall y coupled scalar clouds: analytic treatment in the near-critical regime , Eur

    S. Hod, Charged Gauss-Bonnet black holes supporting non-minimall y coupled scalar clouds: analytic treatment in the near-critical regime , Eur. Phys. J. C 83, 214 (2023)

  36. [44]

    Kostelecky and S

    V.A. Kostelecky and S. Samuel, Gravitational Phenomenology in Higher Dimensional Theori es and Strings , Phys. Rev. D 40, 1886 (1989)

  37. [45]

    Z.F. Mai, R. Xu, D.C. Liang, and L.J. Shao, Extended thermodynamics of the bumblebee black holes , Phys. Rev. D 108, 024004 (2023); arXiv:2304.08030 [gr-qc]

  38. [46]

    Zhang, M

    X. Zhang, M. Wang, and J. Jing, Quasinormal modes and late time tails of perturbation fields on a Schwarzschild- like black hole with a global monopole in the Einstein-bumbl ebee theory, Sci. China Phys. Mech. Astron. 66, 100411 (2023); arXiv:2307.10856 [gr-qc]

  39. [47]

    Casana, A

    R. Casana, A. Cavalcante, F.P. Poulis, and E.B. Santos, Exact Schwarzschild-like solution in a bumblebee gravity model, Phys. Rev. D 97, 104001 (2018); arXiv:1711.02273 [gr-qc]

  40. [48]

    C. Ding, Y. Shi, J. Chen, Y. Zhou, C. Liu, and Y. Xiao, Rotating BTZ-like black hole and central charges in Einstein-bumblebee gravity, Eur. Phys. J. C 83, 573 (2023); arXiv:2302.01580 [gr-qc]

  41. [49]

    C. Chen, Q. Pan, and J. Jing, Quasinormal modes of a scalar perturbation around a rotatin g BTZ-like black hole in Einstein-bumblebee gravity , Phys. Lett. B 846, 138186 (2023), arXiv:2302.05861 [gr-qc]

  42. [50]

    F. Ge, Q. Pan, S. Chen, and J. Jing, Mass ladder operators and quasinormal modes of the static BT Z-like black hole in the Einstein-bumblebee gravity , accepted by Chin. Phys. C

  43. [51]

    Kostelecky and S

    V.A. Kostelecky and S. Samuel, Spontaneous breaking of Lorentz symmetry in string theory , Phys. Rev. D 39, 683 (1989)

  44. [52]

    Bluhm and V.A

    R. Bluhm and V.A. Kostelecky, Spontaneous Lorentz violation, Nambu-Goldstone modes, an d gravity , Phys. Rev. D 71, 065008 (2005); arXiv:hep-th/0412320

  45. [53]

    Bertolami and J

    O. Bertolami and J. Paramos, The Flight of the bumblebee: Vacuum solutions of a gravity mo del with vector-induced spontaneous Lorentz symmetry breaking , Phys. Rev. D 72, 044001 (2005); arXiv:hep-th/0504215

  46. [54]

    Bailey and V.A

    Q.G. Bailey and V.A. Kostelecky, Signals for Lorentz violation in post-Newtonian gravity , Phys. Rev. D 74, 045001 (2006); arXiv:gr-qc/0603030

  47. [55]

    Bluhm, N.L

    R. Bluhm, N.L. Gagne, R. Potting, and A. Vrublevskis, Constraints and Stability in Vector Theories with Spon- taneous Lorentz Violation , Phys. Rev. D 77, 125007 (2008); Erratum ibid. 79 029902 (2009); arXiv:0802.4071 [hep-th]

  48. [56]

    Kostelecky and J

    V.A. Kostelecky and J. Tasson, Prospects for Large Relativity Violations in Matter-Gravi ty Couplings , Phys. Rev. Lett. 102, 010402 (2009); arXiv:0810.1459 [gr-qc]

  49. [57]

    Seifert, Generalized bumblebee models and Lorentz-violating electrodynamics, Phys

    M.D. Seifert, Generalized bumblebee models and Lorentz-violating electrodynamics, Phys. Rev. D 81, 065010 (2010); 17 arXiv:0909.3118 [hep-ph]

  50. [58]

    Maluf, C.A.S

    R.V. Maluf, C.A.S. Almeida, R. Casana, and M. Ferreira, Einstein-Hilbert graviton modes modified by the Lorentz- violating bumblebee Field , Phys. Rev. D 90, 025007 (2014); arXiv:1402.3554 [hep-th]

  51. [59]

    P´ aramos and G

    J. P´ aramos and G. Guiomar, Astrophysical Constraints on the Bumblebee Model , Phys. Rev. D 90, 082002 (2014); arXiv:1409.2022 [astro-ph]

  52. [60]

    Escobar and A

    C.A. Escobar and A. Mart ´ ın-Ruiz, Equivalence between bumblebee models and electrodynamics in a nonlinear gauge, Phys. Rev. D 95, 095006 (2017); arXiv:1703.01171 [hep-th]

  53. [61]

    Assun˜ ao, T

    J.F. Assun˜ ao, T. Mariz, J.R. Nascimento, and A.Y. Petr ov, Dynamical Lorentz symmetry breaking in a tensor bumblebee model, Phys. Rev. D 100, 085009 (2019); arXiv:1902.10592 [hep-th]

  54. [62]

    Capelo and J

    D. Capelo and J. P´ aramos, Cosmological implications of Bumblebee vector models , Phys. Rev. D 91, 104007 (2015); arXiv:1501.07685 [gr-qc]

  55. [63]

    Abramowitz and I

    M. Abramowitz and I. Stegun, Handbook of Mathematical Functions (Academic, New York, 1996)

  56. [64]

    Wang, Quantum and classical aspects of scalar and vector fields aro und black holes , PhD thesis, Aveiro U

    M. Wang, Quantum and classical aspects of scalar and vector fields aro und black holes , PhD thesis, Aveiro U. (2016); arXiv:1606.00811 [gr-qc]

  57. [65]

    Wang, Boundary conditions for Maxwell fields in Kerr-AdS spacetim es, Int

    M. Wang, Boundary conditions for Maxwell fields in Kerr-AdS spacetim es, Int. J. Mod. Phys. D 25, 1641011 (2016)

  58. [66]

    M. Wang, C. Herdeiro and M. O. P. Sampaio, Maxwell perturbations on asymptotically anti-de Sitter sp ace- times: Generic boundary conditions and a new branch of quasi normal modes , Phys. Rev. D 92, 124006 (2015), arXiv:1510.04713 [gr-qc]

  59. [67]

    M. Wang, Z. Chen, X. Tong, Q.Y. Pan, and J.L. Jing, Bifurcation of the Maxwell quasinormal spectrum on asymptotically anti-de Sitter black holes , Phys. Rev. D 103, 064079 (2021); arXiv:2104.04970 [gr-qc]

  60. [68]

    M. Wang, Z. Chen, Q.Y. Pan, and J.L. Jing, Maxwell quasinormal modes on a global monopole Schwarzschi ld- anti-de Sitter black hole with Robin boundary conditions , Eur. Phys. J. C 81, 469 (2021); arXiv:2105.10951 [gr-qc]

  61. [69]

    Brito, V

    R. Brito, V. Cardoso, and P. Pani, Superradiance: New Frontiers in Black Hole Physics , Lect. Notes Phys. 906, 1 (2015); Lect. Notes Phys. 971, 1 (2020); arXiv:1501.06570 [gr-qc]

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