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Post-Newtonian Expansion of Gravitational Waves from a Particle in Circular Orbits around a Rotating Black Hole :Effects of Black Hole Absorption

General Relativity and Quantum Cosmology · Submitted 25 Nov 1997 · 17 references

Pith's verdict: The v^5-versus-v^8 spin result is structurally sound and worth citing; the soft spots are in the higher-order coefficients and one cross-check that doesn't obviously close.

T0 · AI review

How this review was made: An AI referee (selfhosted/deepseek-v4.1-flash) read the paper on November 11, 2026 and answered a fixed list of questions about it. T0 is the starting level every paper gets. The levels describe how deeply Pith has checked the paper, never the authors.

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arXiv IDgr-qc/9711072 (version 1)
Pith IDTCOYJPE5, Pith's permanent record of this paper and its review
Citation(2)Osaka Univ.), Eiichi Takasugi(2) ((1)Nation. Astron. Obs. Japan, Hideyuki Tagoshi(1), Shuhei Mano(2). "Post-Newtonian Expansion of Gravitational Waves from a Particle in Circular Orbits around a Rotating Black Hole :Effects of Black Hole Absorption." arXiv:gr-qc/9711072 (1997). https://pith.science/paper/TCOYJPE5
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The paper

The paper claims

For a particle orbiting a spinning black hole, the share of gravitational-wave energy swallowed by the horizon first appears at order $v^5$ beyond the Newtonian quadrupole formula, three powers of the orbital velocity earlier than for a non

The reading

A small mass spiraling around a black hole radiates gravitational waves, and a fraction of that radiation falls back through the horizon instead of escaping to distant observers. This paper computes that absorbed fraction for a test particle on a circular equatorial orbit around a Kerr black hole, in the limit where the orbital velocity $v$ is small compared with light. Using an analytic scheme for the Teukolsky equation, the authors obtain the horizon energy flux as a power series in $v$ carried through $O(v^8)$ relative to the standard Newtonian quadrupole luminosity. The result changes the bookkeeping: with spin, absorption first appears at order $v^5$, three powers of $v$ earlier than the $v^8$ entry point found for a non-rotating hole, so the effect is much less negligible for spinning systems than the earlier estimate suggested. The authors then feed the rate into an inspiral model and estimate how many wave cycles are lost or gained in the observing band of a ground-based interferometer.

What carries the argument

The engine is the Mano–Suzuki–Takasugi analytic representation of homogeneous Teukolsky solutions: one expansion in hypergeometric functions that converges near the horizon and one in Coulomb wave functions that converges at large radius, joined by a constant $K_ν$ that relates them. The post-Newtonian expansion becomes tractable because the natural small parameters are ordered, $ε=2Mω ∼ v^3$ and $z=ωr ∼ v$, so truncating the series in $ε$ and $z$ is the same as truncating in $v$. The radial solution is then assembled by the Green function method with a source term built from the geodesic circular orbit, and the absorbed flux is read off from the Teukolsky–Press horizon flux formula, whose spin-dependent factor $|C|^2$ supplies the leading $q$-dependence.

Extended reading notes

Core claim

The paper establishes that black hole absorption of gravitational waves from a circular equatorial orbit around a Kerr black hole begins at $O(v^5)$ relative to the Newtonian quadrupole luminosity $(dE/dt)_N = (32/5)(M/r_0)^5 (M/r_0)^{5}$-normalized rate, with leading coefficient $-3q^3/4 - q/4$ where $q=a/M$ is the dimensionless spin. The full total rate is given through $O(v^8)$ in Eq. (4.6), built from per-mode contributions listed in Appendix C and rewritten in the orbital-frequency variable $x=(M/Omega)^{1/3}$ in Appendix D. The authors check that setting $q=0$ collapses the expression to the previously known Schwarzschild result $(dE/dt)_H = (dE/dt)_N v^8$, and that the lowest-order term agrees with Gal'tsov's radiation-reaction formula. They note that the rate can be negative for $q>0$, which they identify as superradiance, and they give the finite $|q| o 1$ limit explicitly. Finally, they estimate the accumulated cycle difference for neutron-star–black-hole binaries, finding values from below $10^{-2}$ cycles up to about 1.5 cycles depending on spin and black hole mass.

Load-bearing premise

The coefficients quoted to $O(v^8)$ are trustworthy only if summing the hypergeometric and Coulomb series to a finite but unspecified number of terms really delivers that accuracy; the authors themselves note in §3 that the post-Newtonian order of the terms is not monotonic for negative index $n$ and that the expansion there must be handled with care, and no truncation-error bound is given.

Editorial extensions

If this is right

  • For a spinning hole, the absorption term enters at the same 2.5-post-Newtonian order as standard radiation-reaction effects, so templates for spinning binaries that omit it are formally incomplete at that order, whereas for a non-spinning hole the $O(v^8)$ entry makes it negligible in the interferometer band.
  • Because the rate can be negative for co-rotating orbits, the horizon can return energy to the orbit rather than draining it, a superradiant contribution that grows in relative importance as the spin approaches extremality.
  • For neutron-star–black-hole binaries the accumulated cycle shift rises with black hole mass, reaching roughly 1.5 cycles for a $70 M_\odot$ hole with $q=0.9$, which is large enough to matter for matched filtering.
  • The machinery is order-by-order in $v$, so extending the series past $O(v^8)$ requires only more terms in the same expansions rather than a new method.
  • The finite $|q| \to 1$ limit given in Eq. (4.11) provides a closed-form check for any future extremal-spin calculation.

Reading between the lines

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

  • Because the leading absorption term is odd in spin and starts at $v^5$, it sits at the same post-Newtonian order as the standard 2.5PN radiation-reaction term; a template that includes one and not the other is internally inconsistent at that order, which suggests the absorption term should be quoted alongside the 2.5PN flux in any spinning-template comparison.
  • The cycle-shift table implies the effect is only marginal for stellar-mass holes but reaches order unity for holes of tens of solar masses; the natural observational target is therefore an intermediate-mass or massive black hole inspiral, where the same $v^5$ term would be far larger.
  • Since the series truncation carries no stated error bound, the cheapest independent check would be a numerical frequency-domain or time-domain Teukolsky solver evaluating the horizon flux at moderate $v$ and high spin, which would either confirm the quoted coefficients or expose a truncation artifact.
  • The restriction to equatorial circular orbits leaves inclined orbits open; there the spin-orbit coupling redistributes power among modes, so the $v^5$ coefficient could pick up an inclination-dependent piece that the present calculation cannot see.
Original abstract

When a particle moves around a Kerr black hole, it radiates gravitational waves.Some of these waves are absorbed by the black hole. We calculate such absorption of gravitational waves induced by a particle of mass mu in a circular orbit on an equatorial plane around a Kerr black hole of mass M. We assume that the velocity of the particle v is much smaller than the speed of light c and calculate the energy absorption rate analytically. We adopt an analytic technique for the Teukolsky equation developed by Mano, Suzuki and Takasugi. We obtain the energy absorption rate to O((v/c)^8) compared to the lowest order. We find that the black hole absorption occurs at O((v/c)^5) beyond the Newtonian-quadrapole luminosity at infinity in the case when the black hole is rotating, which is O((v/c)^3) lower than the non-rotating case. Using the energy absorption rate, we investigate its effects on the orbital evolution of coalescing compact binaries.

The compiled record

The paper's own sentences, arranged, kept beside the review and separate from it. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.

Compiled by classifier-1.13-20260917 via OpenRouter, question bank abstract-p1-20260923, 2026-09-23: 1 request, 5,593 input tokens, $0.0002 reported.

What the abstract itself states, as probabilities: claims first 0.03 · states limitation 0.68 · human participants 0.01 · controlled comparison 0.31 · randomized assignment 0.01 · states quantitative result 0.88 · compares with prior results 0.87 · mentions code or data availability 0.01.

The abstract, sentence by sentence

arXiv listing abstract v1. Results and the main claim are underlined; .

When a particle moves around a Kerr black hole, it radiates gravitational waves.Some of these waves are absorbed by the black hole. We calculate such absorption of gravitational waves induced by a particle of mass mu in a circular orbit on an equatorial plane around a Kerr black hole of mass M. We assume that the velocity of the particle v is much smaller than the speed of light c and calculate the energy absorption rate analytically. We adopt an analytic technique for the Teukolsky equation developed by Mano, Suzuki and Takasugi. We obtain the energy absorption rate to O((v/c)^8) compared to the lowest order. We find that the black hole absorption occurs at O((v/c)^5) beyond the Newtonian-quadrapole luminosity at infinity in the case when the black hole is rotating, which is O((v/c)^3) lower than the non-rotating case. Using the energy absorption rate, we investigate its effects on the orbital evolution of coalescing compact binaries.

background contribution method result interpretation main claim

What the classifier reports for each sentence. The number is the probability it gave the label.
#sentencerolethe authors' own workstates the main conclusionstrength
s0 When a particle moves around a Kerr black hole, it radiates gravitational waves.Some of these waves are absorbed by the black hole. background 1.00 0.06 0.03 asserted 1.00
s1 We calculate such absorption of gravitational waves induced by a particle of mass mu in a circular orbit on an equatorial plane around a Kerr black hole of mass M. contribution 1.00 0.95 0.04 asserted 0.96
s2 We assume that the velocity of the particle v is much smaller than the speed of light c and calculate the energy absorption rate analytically. method 0.93 0.90 0.03 asserted 0.97
s3 We adopt an analytic technique for the Teukolsky equation developed by Mano, Suzuki and Takasugi. method 1.00 0.40 0.02 asserted 0.96
s4 We obtain the energy absorption rate to O((v/c)^8) compared to the lowest order. result 0.72 0.96 0.09 asserted 1.00
s5 We find that the black hole absorption occurs at O((v/c)^5) beyond the Newtonian-quadrapole luminosity at infinity in the case when the black hole is rotating, which is O((v/c)^3) lower than the non-rotating case. result 1.00 0.96 0.78 asserted 1.00
s6 Using the energy absorption rate, we investigate its effects on the orbital evolution of coalescing compact binaries. contribution 0.92 0.93 0.08 asserted 0.66

What kind of paper the classifier reports this is: theoretical result 1.00 · evidence from proof or derivation 1.00.

What was examined, and what was not

sources read
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not examined
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  • figures and tables
  • references and citing sentences
  • relations to other papers
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  • S sections
  • T body sentences
  • C citations
  • R cross-paper relations

Every quoted sentence on this record is the authors'. Every label is from Pith's closed vocabulary, with the probability shown beside it. Every number in the measurements table is the authors', checked by code. Record as JSON

References
How later papers used it

49 later papers cite it

Evidence: substantial. 49 of the citing papers share no author with it, and 10 of those carry a confident label from Pith's citation classifier.

Pith read 15 of the 98 citing sentences, choosing only those whose citation markers point at this paper alone, and wrote the paraphrases from them. The summary, the counts, the evidence level, the links and the quotes come from code; the summary counts the papers listed below. A later paper is listed under a label when Pith's citation classifier gives one of its sentences that label at probability 0.8 or more (0.95 for support), Pith's reading finds that the citing paper itself did it, and a second check confirms the paraphrase against the sentence. This section lists uses only. It does not list criticism or disagreement, so their absence here says nothing about how the paper has been received. Papers that share an author with this one are listed apart, under "By the same authors". A quote is the citing authors' own sentence, shown when their paper's licence is CC BY, CC BY-SA or CC0. JSON

Compares with it 1 of 7 papers with this label
How the literature uses it

45 arXiv papers cite this in 89 sentences

Each citing sentence is taken from the citing paper's LaTeX source and typed by Pith's classifier. A label appears at probability 0.8 or more (0.95 for support), a contest at 0.7 or more; the quoted words are the citing authors'. How each label was checked · JSON

Papers citing it · 61 sentences without a confident label

Contests it 1 paper
Builds on it 1 paper
  • ddt E_h = ∑^2_α=1 v⃗_α·F⃗_α= -325 G_N^-1 (G_N M|x⃗|)^8 (μM)^2 (1 - 4μM + 2 μ^2M^2) [v⃗^2 + 2 (v⃗·x⃗)^2|x⃗|^2], which agrees with and generalizes the result of [ref] valid in the limit $μ≪M$ where black hole perturbation theory holds.

    Horizon radiation reaction forces · Post-Newtonian equations of motion for binary dynamics · 0.91

Uses its method or tool 2 papers
Compares with it 6 papers
Cites it as background 9 papers
  • Complementary work employing the effective-one-body approach has enabled the modeling of the spin evolution in dense clusters in a wide range of parameter space [ref] The broader phenomenon of spin changes due to the re-absorption of angular momentum that was emitted in gravitational radiation is called “tidal-torquing” and has been explored using (semi-) analytic models [ref] .

    Spin-up and mass-gain in hyperbolic encounters of spinning black holes · Introduction · 0.87

  • The tidal heating of black holes was recently investigated by Alvi [ref] , Poisson [ref] , Taylor and Poisson [ref] , and Comeau and Poisson [ref] , building on earlier work by Poisson and Sasaki [ref] and Tagoshi, Mano, and Takasugi [ref] .

    Geometry and dynamics of a tidally deformed black hole · Tidal heating · 0.90

  • Previous theoretical studies of horizon absorption effects include [ref] .

    Absorptive Effects and Classical Black Hole Scattering · Introduction · 1.00

Discussion

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