REVIEW
Self-Interaction Correction to Black Hole Radiance
General Relativity and Quantum Cosmology · Submitted 2 Aug 1994 · 12 references
Pith's verdict: A real, concrete correction to Hawking's spectrum — the derivation is sound in structure, but the one algebraic step that fixes the ω² term is asserted rather than shown.
T0 · AI review
Why Pith says this
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Referee report
The paper
The paper claims
Kraus and Wilczek argue that once the emitted radiation's own gravity is included, Hawking radiation stops being exactly thermal: the exponential suppression of the flux is governed by the black hole's mass after emission, not before, and a
The reading
What carries the argument
The load-bearing object is the reduced Hamiltonian effective action $S = 4dt[p_c 4r + p_t]$ with $p_c$ given by Eq. (3.24), $p_c = 4(2M r) - 4(2M_+ r) + r (4)$, obtained by solving the momentum constraints of spherically symmetric gravity across the shell and fixing the gauge $L=1$, $R=r$. $M_+$ plays the role of the Hamiltonian and is related to the shell momentum by $p = (M_+ - M)/(1 - 4(2M_+/r))$. Because the action is nonlocal, quantization proceeds through the WKB/Hamilton-Jacobi route: the characteristics of the resulting first-order partial differential equation replace geodesics, and the classical action evaluated along them supplies the phase of the mode. The Bogoliubov ratio then follows from a saddle-point evaluation of the time integral, with the saddle displaced into the complex $t$ plane by $t = 4i4M(M-4M)$.
Extended reading notes
Core claim
The paper's central claim is that self-gravitation corrects black hole radiance in a definite, computable way. Working in the Hamiltonian (BCMN) formulation of spherically symmetric gravity, the authors reduce the coupled gravity-shell system to a single degree of freedom, find the canonical momentum conjugate to the shell radius, and identify the exterior mass $M_+$ as the Hamiltonian. Because the effective action is nonlocal, they quantize semiclassically: the phase of the wavefunction obeys a Hamilton-Jacobi equation solved by the method of characteristics, and those characteristics depend on the particle's energy in a way that geodesics do not. For an initial phase $S(0,r)=kr$ near the horizon they carry the calculation through to the late-time form of the mode, then extract the Bogoliubov coefficients by saddle point. The result is $|e^{4(4M-4M-4M)}|$, giving an outgoing flux $F_+ + 8M_+ - 4M_+$ of the form $d4M_+/(2) (4)/(e^{8(4M-4M)}-1)$ — a Planck-like spectrum whose exponential is set by $M-4M$, the mass the hole has after emission.
Load-bearing premise
The whole result rests on truncating to one s-wave spherical shell with the interior mass held fixed and quantizing the resulting nonlocal effective action only semiclassically, and the authors themselves note in a footnote that the neglected virtual transitions to higher partial waves are formally infinite without a ultraviolet completion.
Editorial extensions
If this is right
- The exponential suppression of the emission rate is $e^{-8(4M-4M)4M}$ rather than the standard $e^{-8(4M)4M}$, so the effective temperature is that of the hole after it has radiated, resolving the ambiguity of which mass to use in the thermal formula.
- Massless particles no longer propagate along null geodesics, and the action along a ray is nonzero even for a massless particle, so the geometrical-optics picture of horizon-skimming modes is modified by the particle's own gravitational field.
- The radiation is not exactly Planckian, which removes one of the premises on which the information-loss paradox is usually built.
- The emission can be reinterpreted as negative-energy quanta crossing the horizon in an imaginary time interval $4(4M-4M)$, sharpening the analogy with pair production in an electric field treated by instanton methods.
- The same machinery is stated to extend to Reissner-Nordström and dilaton holes, to charged or massive scalar fields, and to two-shell geometries that would allow the question of correlations in the radiation to be posed.
Reading between the lines
- Because the correction sits in the exponent and is proportional to the emitted energy, it cannot be absorbed into a greybody factor or a rescaled overall temperature; the spectrum drifts as the hole shrinks, so a late-time spectrum is not a single Planck distribution at any one temperature.
- The imaginary-time interval $4(4M-4M)$ is shorter than the $4(4M)$ that would correspond to the initial mass, which suggests reading the correction as a consequence of the horizon area shrinking during emission rather than as an independent dynamical effect.
- The authors' own footnote concedes that virtual transitions to higher partial waves are formally infinite without a ultraviolet completion; if those additive corrections exponentiate rather than stay additive, the numerical coefficient in the exponent would change and the result would be a truncation artifact rather than a physical prediction.
- For astrophysical holes the fractional shift in the exponent is of order $4M/M$, far below observability, so the claim is best read as a consistency statement about the structure of semiclassical gravity rather than as a predicted spectral line.
Original abstract
We consider the modification of the formulas for black hole radiation, due to the self-gravitation of the radiation. This is done by truncating the coupled particle-hole system to a small set of modes, that are plausibly the most significant ones, and quantizing the reduced system. In this way we find that the particles no longer move along geodesics, nor is the action along the rays zero for a massless particle. The radiation is no longer thermal, but is corrected in a definite way that we calculate. Our methods can be extended in a straightforward manner to discuss correlations in the radiation, or between incoming particles and the radiation.
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.
The abstract, sentence by sentence
We consider the modification of the formulas for black hole radiation, due to the self-gravitation of the radiation. This is done by truncating the coupled particle-hole system to a small set of modes, that are plausibly the most significant ones, and quantizing the reduced system. In this way we find that the particles no longer move along geodesics, nor is the action along the rays zero for a massless particle. The radiation is no longer thermal, but is corrected in a definite way that we calculate. Our methods can be extended in a straightforward manner to discuss correlations in the radiation, or between incoming particles and the radiation.
background contribution method result interpretation main claim
| # | sentence | role | the authors' own work | states the main conclusion | strength |
|---|---|---|---|---|---|
| s0 | We consider the modification of the formulas for black hole radiation, due to the self-gravitation of the radiation. | contribution 0.72 | 0.38 | 0.07 | asserted 0.51 |
| s1 | This is done by truncating the coupled particle-hole system to a small set of modes, that are plausibly the most significant ones, and quantizing the reduced system. | method 1.00 | 0.92 | 0.05 | asserted 0.93 |
| s2 | In this way we find that the particles no longer move along geodesics, nor is the action along the rays zero for a massless particle. | result 0.99 | 0.91 | 0.23 | asserted 1.00 |
| s3 | The radiation is no longer thermal, but is corrected in a definite way that we calculate. | result 1.00 | 0.94 | 0.68 | asserted 1.00 |
| s4 | Our methods can be extended in a straightforward manner to discuss correlations in the radiation, or between incoming particles and the radiation. | future work 1.00 | 0.37 | 0.04 | asserted 0.62 |
What was examined, and what was not
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References
How the literature uses it
49 arXiv papers cite this in 131 sentences
Papers citing it · 77 sentences without a confident label
Contests it 1 paper
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For both the neutral and charged case this does not exactly reproduce the result of the original articles [ref] due to a technical error, which was in fact corrected in [ref] for the neutral case.
Extremal Tunneling and Anti-de Sitter Instantons · Evaluating the Bogoliubov coefficients · contest 0.92
Builds on it 2 papers
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We extended the treatment of [ref] to more than one shell [ref] proving on the way the universality of the reduced conjugate momentum within the family of Painlevé gauges [ref] .
Reduced Hamiltonian for intersecting shells and Hawking radiation · Concluding remarks · 1.00
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The perfect-fluid shell model we develop is a generalization of the dust shell model used by Kraus and Wilczek in their attempt to calculate self-interaction corrections to standard Hawking radiation [ref] - [ref] .
Self-gravitating Interferometry and Intrinsic Decoherence · Action Principle · 0.99
Uses its method or tool 11 papers
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We shall keep the formalism for more that one shell as close as possible to the original formalism of [ref] which can be summarized in words that we shall adopt a Painlevé gauge.
Reduced Hamiltonian for intersecting shells and Hawking radiation · Introduction · 0.85
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The method we use to obtain a four-dimensional backreacted decay probability for charged black holes is the tunneling approach to Hawking radiation developed by [ref] .
Extremal Black Hole Decay in de Sitter Space · Introduction · 0.99
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Ensuring that the positive energy solutions decay in time (i.e. into the lower half of $ω'$ plane and $r_in>r_out$) we have after $r$ integration [A similar treatment can be done by taking the contour in the upper half plane but then one has to replace $M→M+ω$ [ref] .], [equation]
Quantum Tunneling and Back Reaction · Introduction · 0.86
Compares with it 8 papers
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It can also be shown [ref] that the expression ([ref]) for the reduced canonical shell momentum $P_c$ is equivalent to the form analogous to the expression given by Kraus and Wilczek [ref] , [equation] despite the different minus sign placement.
Bootstrapping Time Dilation Decoherence · Reduced Phase Space Quantization · 0.91
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To show this, it suffices to calculate [equation] From the flux of outgoing particles with frequencies between $ω$ and $ω+ dω$ [ref] : [equation] We finally arrive at: [equation] Comparing with the Planck distribution [equation] we find that [equation] which is the same expression as the expression for the temperature obtained using the surface gravity in [ref] .
Quantum Gravitational Corrections to Particle Creation by Black Holes · Quantum Gravitational corrections to Hawking radiation · 0.82
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Along the way we will show how the Kraus-Wilczek computation [ref] reduces to the one performed by Parikh and Wilczek [ref] .
Extremal Tunneling and Anti-de Sitter Instantons · Inclusion of gravitational backreaction · 0.80
Cites it as background 15 papers
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In paper [ref] Kraus and Wilczek introduced a semiclassical treatment of Hawking radiation by considering the mechanics of a thin self-gravitating shell of matter in a spherical gravitational field.
On the semiclassical treatment of Hawking radiation · Introduction · 0.95
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As far as the relatively recent research on the tunneling picture of Hawking radiation is concerned, two different approaches are currently very popular, one is the Parikh-Wilczek's semi-classical tunneling method [ref] (based upon the early developments [ref] ), the other is the Hamilton-Jacobi tunneling method [ref] which is developed from the method of complex-path integral proposed in [ref] .
Hawking radiation from rotating AdS black holes in conformal gravity · Introduction · 0.87
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The semiclassical treatment of the Hawking radiation was introduced by Kraus and Wilczek in [ref] after which several developments followed.
Late-time expansion in the semiclassical theory of the Hawking radiation · Introduction · 1.00
Discussion
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