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REVIEW 2 major objections 4 minor 77 references

This paper argues that black-hole ringdown writes a decaying, oscillating modulation onto the near-horizon detailed-balance exponent probed by a falling two-level detector, while preserving the baseline thermal ratio in static limits.

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

T0 review · deepseek-v4-flash

2026-08-03 23:55 UTC pith:CPC376UW

load-bearing objection A genuinely interesting target — ringdown modulation of the detailed-balance exponent — but the derivation as written has load-bearing errors, so the central formula is not established; worth a serious referee, not acceptance in this form. the 2 major comments →

arxiv 2511.03766 v2 pith:CPC376UW submitted 2025-11-05 gr-qc hep-th

Ringdown modulation of acceleration radiation in the Schwarzschild background

classification gr-qc hep-th MSC 83C5783C4781T20 PACS 04.62.+v04.70.Dy04.30.-w04.25.Nx03.65.Yz
keywords ringdowndetailed balanceUnruh-DeWitt detectorquasinormal modesSchwarzschild black holeacceleration radiationeikonal perturbationKMS condition
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved

The pith

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

The paper tries to show that near-horizon thermality, as probed by a freely falling two-level detector coupled to a single outgoing field mode, survives black-hole ringdown but is gently driven. It derives a first-order formula: the detailed-balance exponent ln(Γ_abs/Γ_exc), normally equal to 2πν/κ, picks up a decaying oscillatory correction at the quasinormal frequency, with the geometric response packaged in a coefficient C20(rc) and detector specifics in a prefactor α̃. The modulation vanishes in the zero-amplitude, late-time, and stationary quadrupole limits, so the baseline thermal detailed balance is recovered. Why care: it makes a concrete prediction for how post-merger black holes imprint on an operational quantum-optics observable and isolates which parts of the effect are universal (frequency pair and response coefficient) versus detector-dependent.

Core claim

The central claim is equation (80): ln(Γ_abs/Γ_exc) = 2πν/κ − 2ε α̃ C20(rc)(dv/dτ)_{τ_c} e^{−ω_I v_c} S(ω_R v_c) + O(ε²). Here κ is the Schwarzschild surface gravity, ν the mode frequency, ω_R − iω_I the complex quadrupolar quasinormal frequency, v_c the advanced time at the detector's cavity crossing, and S(θ) = ω_R sin θ − ω_I cos θ. The paper argues that during ringdown the detailed-balance exponent acquires a universal first-order, decaying-oscillatory modulation whose geometric content is carried entirely by the response coefficient C20(rc) and the QNM pair, while the detector gap, switching, and wavepacket profile enter only through the smooth prefactor α̃. This is presented as a contr

What carries the argument

The key object is the linearized eikonal transport equation k^a ∇_a δu = 1/2 h_kk, where h_kk is the double-null contraction of the even-parity, axisymmetric ℓ=2 metric perturbation along the background outgoing null congruence, and δu is the first-order shift of the outgoing retarded time u. The paper writes h_kk as a radial derivative of a combination of the Zerilli-Moncrief master function Ψ20 and its radial derivative, so integrating the transport equation from the horizon to the sampling radius r_c turns the response coefficient C20(rc) into a boundary expression evaluated at r_c. Detector observables are then computed by pulling the corrected eikonal u(τ) = u0(τ) + ε δu(τ) onto the wor

Load-bearing premise

The derivation assumes that the correction δu to the retarded time is obtained by integrating the metric contraction along k^a=(∂_r)^a in ingoing Eddington–Finkelstein coordinates, but in those coordinates (∂_r)^a is the ingoing null direction, not the outgoing one, so the stated condition k^a∇_a u0=0 is false and the computed δu is not the physical outgoing eikonal shift.

What would settle it

Compute k^a∇_a u0 explicitly for u0 = v − 2r* in the paper's ingoing Eddington–Finkelstein coordinates; it equals −2/f(r), which is nonzero, so the transport equation used to derive Eq. (80) has the wrong source. Alternatively, numerically integrate the full even-parity metric perturbation along the true outgoing eikonal and compare the resulting modulation amplitude to C20(rc) from Eq. (88).

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

If this is right

  • Near-horizon single-mode photon statistics remain geometric, but the mean occupation of a weakly leaky cavity inherits a decaying oscillation at the ringdown frequency.
  • The detailed-balance exponent's modulation is fixed by the quasinormal pair and one geometric coefficient, so a measurement can in principle extract ringdown parameters from a detector observable without detailed detector modeling.
  • The result recovers the static Schwarzschild detailed-balance ratio in the zero-amplitude, late-time, and stationary-quadrupole limits.
  • It provides an analytic bridge between black-hole perturbation theory and quantum detector response, and the same transport equation is claimed to extend to other multipoles, parities, and slow rotation.

Where Pith is reading between the lines

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

  • The author's 'universal' phrasing hides a sensitivity: the identification of δu with the perturbed retarded time is the step most likely to fail under closer inspection of the null congruence, so the closed boundary formula for C20(rc) is the part to test numerically.
  • If the transport is corrected to use the genuine outgoing eikonal direction, the qualitative prediction (a decaying sinusoid on the exponent) may still hold, but the exact prefactor C20(rc) would likely change.
  • The framework suggests an analog-gravity test: a slowly modulated Rindler or moving-mirror setup driven at a complex frequency should show the same first-order modulation in detector transition rates.
  • The claimed extension to Kerr at low spin is plausible but untested; the m-dependent Doppler phases introduced by frame dragging could partially cancel the axisymmetric modulation.

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

2 major / 4 minor

Summary. The paper claims to derive, at first order in the ringdown amplitude, a universal decaying-oscillatory modulation of the near-horizon detailed-balance exponent for a freely falling two-level detector coupled to a single outgoing Schwarzschild mode. Working in ingoing Eddington-Finkelstein coordinates, the authors compute a perturbed outgoing eikonal u = u0 + ε δu by integrating a transport equation sourced by the double-null contraction h_kk, pull this back to the detector worldline, and expand the excitation/absorption probabilities. The main result, Eq. (80), states that ln(Γ_abs/Γ_exc) = 2πν/κ − 2ε α̃ C20(rc)(dv/dτ)_{τ_c} e^{-ω_I v_c} S(ω_R v_c) + O(ε²), with a closed boundary formula for C20(rc). The paper also supplies a static-limit proposition, numerical illustrations, and extensive appendices on EF reconstruction and gauge issues.

Significance. If correct, the result would give a concrete, falsifiable connection between black-hole ringdown and an operational detector-based thermality diagnostic, extending the static detailed-balance setup of [10] into the time-dependent regime. The paper has several virtues: it clearly separates geometric data (QNM frequencies, response coefficient) from detector-specific prefactors, it attempts a manifestly horizon-regular treatment, and it provides closed-form expressions that could be tested numerically. However, the central derivation contains a fundamental error in identifying the null generator used to propagate the retarded-time correction, and the baseline probability calculation conflates the mode frequency ν with the detector gap ω_A. These issues are load-bearing: they invalidate the derivation of Eq. (80), so the advertised result is not established by this manuscript.

major comments (2)
  1. [III.A, Eqs. (29), (37)–(42)] The transport equation is solved along the wrong null direction. Under the explicit dyad choice (37), k^a = (∂_r)^a in ingoing EF coordinates, while the background outgoing eikonal is u0 = v − 2r*. Direct computation gives k^a∇_a u0 = ∂_r u0 = −2/(1−2M/r) ≠ 0, contradicting the normalization condition k^a∇_a u0 = 0 stated in Eq. (29). The vector that annihilates u0 is the paper's own n^a = −(∂_v)^a − (f/2)(∂_r)^a, not k^a. Consequently, integrating ∂_r δu = ½ h_kk from the horizon to r_c does not produce a correction to the retarded time; it produces a quantity transported along the ingoing null congruence. The correct source is the contraction of h_ab with ∇^a u0, i.e. a combination of the form h_vv + f h_vr + (f²/4) h_rr, not h_rr. Since the main formula (80) depends explicitly on the resulting δu, the central result is not derived.
  2. [III.C, Eqs. (59)–(61)] The baseline probability integrals are evaluated at the detector frequency rather than the mode frequency. In Eq. (60), the kernels F∓(ν, κ, ω_A) are defined as Fourier transforms containing only ω_A s and the thermal kernel in the variable u0(τ); they have no dependence on ν. Yet Eq. (61) claims F+ = e^{2πν/κ}/(e^{2πν/κ}−1) A0, with the Boltzmann factor determined by ν. A standard evaluation of the ω_A-dependent integral would give a factor involving ω_A/κ, not ν, unless ω_A = ν, which is not assumed (only ν ≲ ω_A). No single-mode projection e^{-iν(u−u′)} is introduced in G+_out before this step. Thus the baseline detailed-balance ratio Γ_abs/Γ_exc = e^{2πν/κ} is not obtained from the written integrals, and the perturbed ratio (75)–(80) inherits this unsupported structure.
minor comments (4)
  1. [Eq. (29) vs. Eq. (37)] The notation k^a/n^a in the dyad is reversed relative to standard usage: the vector labeled k^a is tangent to ingoing null rays, while the vector labeled n^a is the outgoing principal null vector. This causes the inconsistency noted above and should be corrected throughout.
  2. [Fig. 1] The vertical axis label appears truncated: it reads '20(rc)' rather than 'C20(rc)'.
  3. [Theorem 1 assumptions] The assumption 'EF-regular gauge within Ξ(rc)=0' is used before Ξ is defined (Appendix D); the theorem statement should either define it or refer forward explicitly.
  4. [General presentation] The paper is unusually long and contains many appendices of varying relevance. A tighter presentation, with the main derivation separated from numerical/technical material, would improve readability.

Circularity Check

0 steps flagged

No significant circularity: Eq. (80) is a first-order Taylor expansion of the externally sourced detailed-balance baseline under an assumed QNM perturbation; no fitted parameter is renamed as a prediction and no load-bearing self-citation chain appears.

full rationale

The central claim (Eq. 80) is obtained by linearizing the outgoing eikonal about the Schwarzschild baseline, sourcing the correction δu from the double-null contraction hkk of an assumed even-parity QNM (frequencies ωR, ωI and amplitude A20 supplied externally, not fitted to the detector observable), and then expanding the single-mode transition probabilities to first order in ε. The baseline detailed-balance factor exp(2πν/κ) is re-derived in Eqs. (7)-(9) from the near-horizon logarithmic phase and a standard gamma-function integral, citing Scully et al. [10] for the operational setup but not importing its conclusion as an unverified premise. The detector prefactor α̃ is computed in Appendix A from the switching autocorrelation and phase integrals, not adjusted to reproduce Eq. (80). C20(rc) is given algebraically from the Zerilli master function via the paper's own EF-regular reconstruction (Appendices B-C), with the residual gauge condition Ξ(rc)=0 fixing a boundary constant rather than fitting the final ratio. Self-citations [46]-[48] appear only as contextual related work and are not used to justify the modulation, the uniqueness claims, or any input. No uniqueness theorem from prior work by the authors is imported as an external mathematical fact. The skeptical null-generator objection (k^a=(∂_r)^a in EF coordinates does not annihilate the outgoing eikonal u0) is a correctness/consistency issue in the perturbation theory, not a circularity of the kind where an output equals an input by construction; under the scoring rules it does not affect the circularity score.

Axiom & Free-Parameter Ledger

0 free parameters · 4 axioms · 0 invented entities

The paper introduces no fitted free parameters or new entities. The central claim rests on standard background assumptions (Rindler reduction, chiral Wightman function) plus an asserted but underived EF reconstruction of h_kk. The critical flaw is in the null-vector identification used for the transport equation, which is not listed as an axiom but is a load-bearing mathematical input.

axioms (4)
  • domain assumption The Schwarzschild background near the horizon admits the Rindler reduction with the universal logarithmic map u0(τ) = u0 − κ^{-1} ln[κ(τ_H−τ)] for a radially infalling worldline.
    Used throughout to evaluate the baseline probabilities (Eqs 5, 26, 44); standard and well-supported, but not proven in this paper.
  • domain assumption The outgoing-sector vacuum Wightman function has the chiral form G+_out(u,u') = -1/(4π²)/(u-u'-iϵ)² and satisfies KMS at β=2π/κ.
    Eqs (47)-(49); standard result, but the projection to a single mode of frequency ν is not implemented, leading to the ω_A-vs-ν mismatch in Sec. III.C.
  • ad hoc to paper The even-parity ℓ=2 metric perturbation is reconstructed in EF-regular gauge as h_kk = ∂_r[a2(r)Ψ20 + b2(r)∂_rΨ20], with a2,b2 as in Eq (90).
    This reconstruction is the central input for C20(r_c); it is asserted rather than derived in Appendices B-C, and no proof of uniqueness is given.
  • domain assumption The detector-field interaction is described by the Unruh-DeWitt monopole coupling with rotating-wave approximation, and the atom crosses the cavity in a narrow window.
    Eqs (31)-(33), standard for this program; requires the adiabatic conditions (34).

pith-pipeline@v1.3.0-alltime-deepseek · 29793 in / 20084 out tokens · 173859 ms · 2026-08-03T23:55:13.618642+00:00 · methodology

0 comments
read the original abstract

We derive an analytic first-order description of how Schwarzschild ringdown affects a detector-based detailed-balance diagnostic in a near-horizon, single-mode setting. A freely falling two-level system couples to a cavity-filtered outgoing mode of fixed asymptotic frequency, whose static Schwarzschild response gives geometric photon statistics and a detailed-balance ratio governed by the surface gravity. We perturb this baseline by an even-parity, axisymmetric quadrupolar quasinormal mode and work in ingoing Eddington-Finkelstein coordinates, regular at the future horizon. The perturbation shifts the outgoing eikonal through the double-null contraction of the metric perturbation along the outgoing congruence. After fixing the residual endpoint phase calibration on the cavity worldtube, this redshift-map deformation induces a first-order decaying-oscillatory correction to the detector detailed-balance exponent at the quasinormal frequency. We express the geometric response through a closed boundary formula at the sampling radius and state the adiabatic, narrowband, and linear-response conditions under which the result applies. Detector details, including the gap, switching, and wavepacket profile, enter only through a smooth prefactor, while the ringdown dependence is carried by the quasinormal frequency and calibrated response coefficient. The modulation vanishes in the zero-amplitude, late-time, and stationary quadrupolar limits. The result is not a modification of the Hawking temperature, global Hawking flux, or dynamical horizon thermality, but a controlled correction to an operational detector/cavity detailed-balance observable.

Figures

Figures reproduced from arXiv: 2511.03766 by Reggie C. Pantig.

Figure 1
Figure 1. Figure 1: FIG. 1. Single-mode result [PITH_FULL_IMAGE:figures/full_fig_p005_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: FIG. 2. Ringdown kernel [PITH_FULL_IMAGE:figures/full_fig_p011_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: FIG. 3. Log detailed-balance ratio [PITH_FULL_IMAGE:figures/full_fig_p012_3.png] view at source ↗

discussion (0)

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Reference graph

Works this paper leans on

77 extracted references · 30 linked inside Pith

  1. [1]

    Asε→0orv c → ∞, the modulation vanishes and we recover the Schwarzschild baseline, Γabs Γexc →exp 2πν κ .(83)

  2. [2]

    Only the double-null contraction hkk enters; with EF regularity and fixed normalization of ka, δu and hence (79)-(80) are gauge invariant up to an irrelevant constant set byδu| r=2M = 0

  3. [3]

    Iterating detector transits in a weakly leaky cavity yields a geometric photon number distribution with a time-dependent parameter, pn(vc) = h 1−e −2ξ(vc) i e−2ξ(vc)n,2ξ(v c) = ln Γabs Γexc from (80).(84) Thus¯n(vc) = e2ξ(vc) −1 −1 inherits the same decaying oscillatory imprint of the ringdown

  4. [4]

    The static exponent(2 πν/κ)depends on the mode frequency ν (not the detector gap), exactly as in Ref. [ 10]. Detector specifics, includingω A, enter only through the smooth prefactor˜αmultiplying the modulation. As we see, Theorem 1 makes precise the sense in which near-horizon thermality is adiabatically robust: detailed balance remains geometric, but th...

  5. [5]

    Short transit vs. curvature/redshift scales, κδτc ≪1, ω I δτc ≪1.(100) The first condition ensures that the near-horizon logarithm in u0 dominates over any slow background variation during a single crossing; the second keeps the QNM envelopee −ωI v(τ) quasi-constant across the window

  6. [6]

    The static detailed-balance exponent depends on ν (not on ωA), exactly as in II A

    Mode and detector frequencies, κ≪ν≲ω A,∆ν≪ν(101) so that the outgoing mode is sharply defined relative to geometric scales and the single-mode description (with wavepacket width∆ ν)is justified. The static detailed-balance exponent depends on ν (not on ωA), exactly as in II A. 16

  7. [7]

    Linear response and small modulation, 0< ε≪1, ε ˜αC20(rc) dv dτ τc e−ωI vc ≪1.(102) This ensures the O(ε)expansion is controlled and the multiplicative correction in (79)-(80) remains perturbative at all relevantv c. We comment the following: (i) The Rindler map (99) is universal for any radial free fall with E≥ 1; changing E rescales only smooth prefacto...

  8. [8]

    For( ℓ, m) ̸= (20), one replaces Y20(0)by Yℓm(θ, ϕ)along the chosen worldline and uses the corresponding reconstruction (odd parity via Regge-Wheeler; even parity via Zerilli)

    Other multipoles and parities.The transport equation ka∇aδu = 1 2 hkk holds generically. For( ℓ, m) ̸= (20), one replaces Y20(0)by Yℓm(θ, ϕ)along the chosen worldline and uses the corresponding reconstruction (odd parity via Regge-Wheeler; even parity via Zerilli). The net effect is a different, but equally algebraic, coefficient Cℓm(rc)and the same decay...

  9. [9]

    Frame dragging introduces m-dependent Doppler phases; the modulation remains of the form (113), withω→ω ℓmn(a)and a spin-correctedC ℓm(rc;a)

    Rotation (Kerr) at first order in spin.For slowly rotating holes [ 64], one may treat a/M≪ 1: replace the Zerilli/RW system by Teukolsky’s equation plus metric reconstruction (e.g., Chrzanowski-Kegeles/Wald) and build the Kerr analogue of hkk. Frame dragging introduces m-dependent Doppler phases; the modulation remains of the form (113), withω→ω ℓmn(a)and...

  10. [10]

    Multi-pass cavities or stationary arrays of detectors would convert the transient modulation into a phase-sensitive steady-state pattern inp n

    Detector/worldline variations.Nonradial infall or finite E̸ = 1modifies smooth prefactors and the mapping τ7→v (τ ) but leaves the universal near-horizon logarithm and the structure of (113) intact. Multi-pass cavities or stationary arrays of detectors would convert the transient modulation into a phase-sensitive steady-state pattern inp n

  11. [11]

    Beyond scalars.For electromagnetic or gravitational perturbations probed by appropriately coupled detectors, the same geometric driver hkk (with the relevant spin-weighted master fields) yields an identical modulation principle; only the algebraic map from master variables toh kk changes

  12. [12]

    Our derivation already isolates where these enter (autocorrelation W (s)and higher derivatives of δu); Appendix B can be extended to give explicitO(ω I ∆τc)corrections

    Beyond the adiabatic window.If ωI ∆τc ̸≪ 1or κ∆τc ̸≪ 1, next-order terms produce controlled phase-mixing corrections. Our derivation already isolates where these enter (autocorrelation W (s)and higher derivatives of δu); Appendix B can be extended to give explicitO(ω I ∆τc)corrections

  13. [13]

    These remain subleading under our perturbative bound and could be systematically included by iterating the transport/Wightman expansion

    Higher orders and backreaction.At O(ε2), mode-mode couplings induce a DC shift and second-harmonic terms in the exponent. These remain subleading under our perturbative bound and could be systematically included by iterating the transport/Wightman expansion. Our analysis sharpens the operational meaning of black hole: it is robust but not rigid. The equil...

  14. [14]

    Black hole explosions,

    S. W. Hawking, “Black hole explosions,” Nature248, 30–31 (1974)

  15. [15]

    Particle Creation by Black Holes,

    S. W. Hawking, “Particle Creation by Black Holes,” Commun. Math. Phys.43, 199–220 (1975), [Erratum: Commun.Math.Phys. 46, 206 (1976)]

  16. [16]

    Hawking,Recent Developments in Gravitation(Springer US, 1979) pp

    Stephen W. Hawking,Recent Developments in Gravitation(Springer US, 1979) pp. 145–173

  17. [17]

    Gibbons and S.W

    G.W. Gibbons and S.W. Hawking,Euclidean Quantum Gravity, G - Reference,Information and Interdisciplinary Subjects Series (World Scientific, 1993)

  18. [18]

    Thermodynamics of black holes,

    P. C. W. Davies, “Thermodynamics of black holes,” Rept. Prog. Phys.41, 1313–1355 (1978)

  19. [19]

    The thermodynamics of black holes,

    Robert M. Wald, “The thermodynamics of black holes,” Living Rev. Rel.4, 6 (2001), arXiv:gr-qc/9912119

  20. [20]

    Statistical mechanical theory of irreversible processes. 1. General theory and simple applications in magnetic and conduction problems,

    Ryogo Kubo, “Statistical mechanical theory of irreversible processes. 1. General theory and simple applications in magnetic and conduction problems,” J. Phys. Soc. Jap.12, 570–586 (1957)

  21. [21]

    Theory of many particle systems. 1

    Paul C. Martin and Julian S. Schwinger, “Theory of many particle systems. 1.” Phys. Rev.115, 1342–1373 (1959)

  22. [22]

    Vacuum Noise and Stress Induced by Uniform Acceleration: Hawking-Unruh Effect in Rindler Manifold of Arbitrary Dimension,

    Shin Takagi, “Vacuum Noise and Stress Induced by Uniform Acceleration: Hawking-Unruh Effect in Rindler Manifold of Arbitrary Dimension,” Prog. Theor. Phys. Suppl.88, 1–142 (1986)

  23. [23]

    Quantum optics approach to radiation from atoms falling into a black hole,

    Marlan O. Scully, Stephen Fulling, David Lee, Don N. Page, Wolfgang Schleich, and Anatoly Svidzinsky, “Quantum optics approach to radiation from atoms falling into a black hole,” Proc. Nat. Acad. Sci.115, 8131–8136 (2018), arXiv:1709.00481 [quant-ph]

  24. [24]

    Scattering of Gravitational Radiation by a Schwarzschild Black-hole,

    C. V. Vishveshwara, “Scattering of Gravitational Radiation by a Schwarzschild Black-hole,” Nature227, 936–938 (1970)

  25. [25]

    Perturbations of a rotating black hole. 1. Fundamental equations for gravitational electromagnetic and neutrino field perturbations,

    Saul A. Teukolsky, “Perturbations of a rotating black hole. 1. Fundamental equations for gravitational electromagnetic and neutrino field perturbations,” Astrophys. J.185, 635–647 (1973)

  26. [26]

    Solutions to a generalized spheroidal wave equation: Teukolsky’s equations in general relativity, and the two-center problem in molecular quantum mechanics,

    E. W. Leaver, “Solutions to a generalized spheroidal wave equation: Teukolsky’s equations in general relativity, and the two-center problem in molecular quantum mechanics,” J. Math. Phys.27, 1238 (1986)

  27. [27]

    Quasinormal modes of stars and black holes,

    Kostas D. Kokkotas and Bernd G. Schmidt, “Quasinormal modes of stars and black holes,” Living Rev. Rel.2, 2 (1999), arXiv:gr-qc/9909058

  28. [28]

    Quasinormal modes of black holes and black branes,

    Emanuele Berti, Vitor Cardoso, and Andrei O. Starinets, “Quasinormal modes of black holes and black branes,” Class. Quant. Grav.26, 163001 (2009), arXiv:0905.2975 [gr-qc]

  29. [29]

    Quasinormal modes of black holes: From astrophysics to string theory,

    R. A. Konoplya and A. Zhidenko, “Quasinormal modes of black holes: From astrophysics to string theory,” Rev. Mod. Phys.83, 793–836 (2011), arXiv:1102.4014 [gr-qc]

  30. [30]

    Observation of Gravitational Waves from a Binary Black Hole Merger,

    B. P. Abbottet 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]

  31. [31]

    Notes on black hole evaporation,

    W. G. Unruh, “Notes on black hole evaporation,” Phys. Rev. D14, 870 (1976)

  32. [32]

    Quantum fields on manifolds: PCT and gravitationally induced thermal states,

    Geoffrey L. Sewell, “Quantum fields on manifolds: PCT and gravitationally induced thermal states,” Annals Phys.141, 201–224 (1982)

  33. [33]

    Theorems on the Uniqueness and Thermal Properties of Stationary, Nonsingular, Quasifree States on Space-Times with a Bifurcate Killing Horizon,

    Bernard S. Kay and Robert M. Wald, “Theorems on the Uniqueness and Thermal Properties of Stationary, Nonsingular, Quasifree States on Space-Times with a Bifurcate Killing Horizon,” Phys. Rept.207, 49–136 (1991)

  34. [34]

    Stability of a Schwarzschild singularity,

    Tullio Regge and John A. Wheeler, “Stability of a Schwarzschild singularity,” Phys. Rev.108, 1063–1069 (1957)

  35. [35]

    Gravitational field of a particle falling in a schwarzschild geometry analyzed in tensor harmonics,

    F. J. Zerilli, “Gravitational field of a particle falling in a schwarzschild geometry analyzed in tensor harmonics,” Phys. Rev. D2, 2141–2160 (1970)

  36. [36]

    Gravitational perturbations of spherically symmetric systems. I. The exterior problem

    V. Moncrief, “Gravitational perturbations of spherically symmetric systems. I. The exterior problem.” Annals Phys.88, 323–342 (1974)

  37. [37]

    On the Derivation of Hawking Radiation Associated With the Formation of a Black Hole,

    Klaus Fredenhagen and Rudolf Haag, “On the Derivation of Hawking Radiation Associated With the Formation of a Black Hole,” Commun. Math. Phys.127, 273 (1990)

  38. [38]

    A Comparison of Whitehead’s and Einstein’s Formulæ,

    A. S. Eddington, “A Comparison of Whitehead’s and Einstein’s Formulæ,” Nature113, 192–192 (1924)

  39. [39]

    Past-Future Asymmetry of the Gravitational Field of a Point Particle,

    David Finkelstein, “Past-Future Asymmetry of the Gravitational Field of a Point Particle,” Phys. Rev.110, 965–967 (1958)

  40. [40]

    Bryce DeWitt,On the Path of Albert Einstein(Springer US, 1979) pp. 127–143

  41. [41]

    How often does the Unruh-DeWitt detector click? Regularisation by a spatial profile,

    Jorma Louko and Alejandro Satz, “How often does the Unruh-DeWitt detector click? Regularisation by a spatial profile,” Class. Quant. Grav.23, 6321–6344 (2006), arXiv:gr-qc/0606067

  42. [42]

    The Unruh effect and its applications,

    Luis C. B. Crispino, Atsushi Higuchi, and George E. A. Matsas, “The Unruh effect and its applications,” Rev. Mod. Phys.80, 787–838 (2008), arXiv:0710.5373 [gr-qc]

  43. [43]

    Unruh-DeWitt detector in dimensionally-reduced static spherically symmetric spacetimes,

    Erickson Tjoa and Robert B. Mann, “Unruh-DeWitt detector in dimensionally-reduced static spherically symmetric spacetimes,” JHEP03, 014 (2022), arXiv:2202.04084 [gr-qc]

  44. [44]

    Response of an Unruh-DeWitt detector near an extremal black hole,

    Aindri´ u Conroy and Peter Taylor, “Response of an Unruh-DeWitt detector near an extremal black hole,” Phys. Rev. D105, 27 085001 (2022), arXiv:2109.04486 [gr-qc]

  45. [45]

    Excitation of an Atom by a Uniformly Accelerated Mirror through Virtual Transitions,

    Anatoly A. Svidzinsky, Jonathan S. Ben-Benjamin, Stephen A. Fulling, and Don N. Page, “Excitation of an Atom by a Uniformly Accelerated Mirror through Virtual Transitions,” Phys. Rev. Lett.121, 071301 (2018)

  46. [46]

    Unruh Acceleration Radiation Revisited,

    J. S. Ben-Benjaminet al., “Unruh Acceleration Radiation Revisited,” Int. J. Mod. Phys. A34, 1941005 (2019), arXiv:1906.01729 [quant-ph]

  47. [47]

    Acceleration radiation of an atom freely falling into a Kerr black hole and near-horizon conformal quantum mechanics,

    A. Azizi, H. E. Camblong, A. Chakraborty, C. R. Ordonez, and M. O. Scully, “Acceleration radiation of an atom freely falling into a Kerr black hole and near-horizon conformal quantum mechanics,” Phys. Rev. D104, 065006 (2021), arXiv:2011.08368 [gr-qc]

  48. [48]

    Quantum optics meets black hole ther- modynamics via conformal quantum mechanics: I. Master equation for acceleration radiation,

    A. Azizi, H. E. Camblong, A. Chakraborty, C. R. Ordonez, and M. O. Scully, “Quantum optics meets black hole ther- modynamics via conformal quantum mechanics: I. Master equation for acceleration radiation,” Phys. Rev. D104(2021), 10.1103/PhysRevD.104.084086, arXiv:2108.07570 [gr-qc]

  49. [49]

    Quantum optics meets black hole ther- modynamics via conformal quantum mechanics: II. Thermodynamics of acceleration radiation,

    A. Azizi, H. E. Camblong, A. Chakraborty, C. R. Ordonez, and M. O. Scully, “Quantum optics meets black hole ther- modynamics via conformal quantum mechanics: II. Thermodynamics of acceleration radiation,” Phys. Rev. D104(2021), 10.1103/PhysRevD.104.084085, arXiv:2108.07572 [gr-qc]

  50. [50]

    Near-horizon aspects of acceleration radiation by free fall of an atom into a black hole,

    H. E. Camblong, A. Chakraborty, and C. R. Ordonez, “Near-horizon aspects of acceleration radiation by free fall of an atom into a black hole,” Phys. Rev. D102, 085010 (2020), arXiv:2009.06580 [gr-qc]

  51. [51]

    Near horizon aspects of acceleration radiation of an atom falling into a class of static spherically symmetric black hole geometries,

    Soham Sen, Rituparna Mandal, and Sunandan Gangopadhyay, “Near horizon aspects of acceleration radiation of an atom falling into a class of static spherically symmetric black hole geometries,” Phys. Rev. D106, 025004 (2022), arXiv:2205.11260 [gr-qc]

  52. [52]

    Equivalence principle and HBAR entropy of an atom falling into a quantum corrected black hole,

    Soham Sen, Rituparna Mandal, and Sunandan Gangopadhyay, “Equivalence principle and HBAR entropy of an atom falling into a quantum corrected black hole,” Phys. Rev. D105, 085007 (2022), arXiv:2202.00671 [hep-th]

  53. [53]

    Horizon brightened accelerated radiation in the background of braneworld black holes,

    Ashmita Das, Soham Sen, and Sunandan Gangopadhyay, “Horizon brightened accelerated radiation in the background of braneworld black holes,” Phys. Rev. D109, 064087 (2024), arXiv:2311.13557 [gr-qc]

  54. [54]

    Derivative coupling in horizon brightened acceleration radiation: A quantum optics approach,

    Ashmita Das, Anjana Krishnan, Soham Sen, and Sunandan Gangopadhyay, “Derivative coupling in horizon brightened acceleration radiation: A quantum optics approach,” Phys. Rev. D112, 065006 (2025), arXiv:2505.16897 [gr-qc]

  55. [55]

    Atom falling into a quantum corrected charged black hole and HBAR entropy,

    Arpita Jana, Soham Sen, and Sunandan Gangopadhyay, “Atom falling into a quantum corrected charged black hole and HBAR entropy,” Phys. Rev. D110, 026029 (2024), arXiv:2405.13087 [gr-qc]

  56. [56]

    Inverse logarithmic correction in the horizon brightened acceleration radiation entropy of an atom falling into a renormalization group improved charged black hole,

    Arpita Jana, Soham Sen, and Sunandan Gangopadhyay, “Inverse logarithmic correction in the horizon brightened acceleration radiation entropy of an atom falling into a renormalization group improved charged black hole,” Phys. Rev. D111, 085017 (2025), arXiv:2501.17579 [gr-qc]

  57. [57]

    Nonthermal acceleration radiation of atoms near a black hole in presence of dark energy,

    Syed Masood A. S. Bukhari, Imtiyaz Ahmad Bhat, Chenni Xu, and Li-Gang Wang, “Nonthermal acceleration radiation of atoms near a black hole in presence of dark energy,” Phys. Rev. D107, 105017 (2023), arXiv:2211.08793 [gr-qc]

  58. [58]

    Seeing dark matter via acceleration radiation,

    Syed Masood A. S. Bukhari and Li-Gang Wang, “Seeing dark matter via acceleration radiation,” Phys. Rev. D109, 045009 (2024), arXiv:2309.11958 [gr-qc]

  59. [59]

    HBAR entropy of Infalling Atoms into a GUP-corrected Schwarzschild Black Hole and equivalence principle,

    Ali ¨Ovg¨ un and Reggie C. Pantig, “HBAR entropy of Infalling Atoms into a GUP-corrected Schwarzschild Black Hole and equivalence principle,” (2025), arXiv:2506.10621 [gr-qc]

  60. [60]

    Acceleration radiation from derivative-coupled atoms falling in modified gravity black holes,

    Reggie C. Pantig and Ali ¨Ovg¨ un, “Acceleration radiation from derivative-coupled atoms falling in modified gravity black holes,” Eur. Phys. J. C85, 1183 (2025), arXiv:2508.11734 [gr-qc]

  61. [61]

    Floquet resonances and redshift-enhanced acceleration radiation from vibrating atoms in Schwarzschild spacetime,

    Reggie C. Pantig, Ali ¨Ovg¨ un, Syed Masood, and Li-Gang Wang, “Floquet resonances and redshift-enhanced acceleration radiation from vibrating atoms in Schwarzschild spacetime,” (2025), arXiv:2510.11761 [gr-qc]

  62. [62]

    Near horizon local instability and quantum thermality,

    Surojit Dalui and Bibhas Ranjan Majhi, “Near horizon local instability and quantum thermality,” Phys. Rev. D102, 124047 (2020), arXiv:2007.14312 [gr-qc]

  63. [63]

    Influence through mixing: hotspots as benchmarks for basic black-hole behaviour,

    G. Kaplanek, C. P. Burgess, and R. Holman, “Influence through mixing: hotspots as benchmarks for basic black-hole behaviour,” JHEP09, 006 (2021), arXiv:2106.09854 [hep-th]

  64. [64]

    What Hawking radiation looks like as you fall into a black hole,

    Christopher J. Shallue and Sean M. Carroll, “What Hawking radiation looks like as you fall into a black hole,” Phys. Rev. D112, 085013 (2025), arXiv:2501.06609 [gr-qc]

  65. [65]

    Toward a self-consistent framework for measuring black hole ringdowns,

    Teagan A. Clarkeet al., “Toward a self-consistent framework for measuring black hole ringdowns,” Phys. Rev. D109, 124030 (2024), arXiv:2402.02819 [gr-qc]

  66. [66]

    Black hole spectroscopy: status report,

    Gregorio Carullo, “Black hole spectroscopy: status report,” Gen. Rel. Grav.57, 76 (2025)

  67. [67]

    On the gravitational field of a mass point according to Einstein’s theory,

    Karl Schwarzschild, “On the gravitational field of a mass point according to Einstein’s theory,” Sitzungsber. Preuss. Akad. Wiss. Berlin (Math. Phys. )1916, 189–196 (1916), arXiv:physics/9905030

  68. [68]

    Wald,General Relativity(Chicago Univ

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

  69. [69]

    Carroll,Spacetime and Geometry: An Introduction to General Relativity(Cambridge University Press, 2019)

    Sean M. Carroll,Spacetime and Geometry: An Introduction to General Relativity(Cambridge University Press, 2019)

  70. [70]

    Quantum fields in curved spacetime,

    Stefan Hollands and Robert M. Wald, “Quantum fields in curved spacetime,” Phys. Rept.574, 1–35 (2015), arXiv:1401.2026 [gr-qc]

  71. [71]

    Timelike and null geodesics in the Kerr metric,

    J. M. Bardeen, “Timelike and null geodesics in the Kerr metric,” Proceedings, Ecole d’Et´ e de Physique Th´ eorique: Les Astres Occlus : Les Houches, France, August, 1972, 215-240 , 215–240 (1973)

  72. [72]

    Gravitational perturbations of the Schwarzschild spacetime: A Practical covariant and gauge- invariant formalism,

    Karl Martel and Eric Poisson, “Gravitational perturbations of the Schwarzschild spacetime: A Practical covariant and gauge- invariant formalism,” Phys. Rev. D71, 104003 (2005), arXiv:gr-qc/0502028

  73. [73]

    Subrahmanyan Chandrasekhar,The mathematical theory of black holes(Oxford University Press, 1985)

  74. [74]

    An Analytic representation for the quasi normal modes of Kerr black holes,

    E. W. Leaver, “An Analytic representation for the quasi normal modes of Kerr black holes,” Proc. Roy. Soc. Lond. A402, 285–298 (1985)

  75. [75]

    Quasinormal modes of Schwarzschild black holes: The determination of quasinormal frequencies with very large imaginary parts,

    Hans-Peter Nollert, “Quasinormal modes of Schwarzschild black holes: The determination of quasinormal frequencies with very large imaginary parts,” Phys. Rev. D47, 5253–5258 (1993)

  76. [76]

    N. D. Birrell and P. C. W. Davies,Quantum Fields in Curved Space, Cambridge Monographs on Mathematical Physics (Cambridge 28 University Press, Cambridge, UK, 1982)

  77. [77]

    Scalar, Electromagnetic and Gravitational Perturbations of Kerr-Newman Black Holes in the Slow-Rotation Limit,

    Paolo Pani, Emanuele Berti, and Leonardo Gualtieri, “Scalar, Electromagnetic and Gravitational Perturbations of Kerr-Newman Black Holes in the Slow-Rotation Limit,” Phys. Rev. D88, 064048 (2013), arXiv:1307.7315 [gr-qc]