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The Conical Singularity And Quantum Corrections To Entropy Of Black Hole

High Energy Physics - Theory · Submitted 1 Jul 1994 · 35 references

Pith's verdict: The structural claim — Schwarzschild carries an extra mass-independent log divergence that Rindler does not — is the real contribution, but the printed algebra from B4 to the 1/45 coefficient does not close.

T0 · AI review

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arXiv IDhep-th/9407001 (version 1)
Pith IDUMFJZTUX, Pith's permanent record of this paper and its review
CitationS.N.Solodukhin. "The Conical Singularity And Quantum Corrections To Entropy Of Black Hole." arXiv:hep-th/9407001 (1994). https://pith.science/paper/UMFJZTUX
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Referee report
The paper

The paper claims

The paper argues that smoothing the Euclidean cone reveals an extra logarithmic divergence in Schwarzschild black-hole entropy that survives the infinite-mass limit.

The reading

The paper asks how one-loop matter fluctuations change the Bekenstein-Hawking entropy when the Euclidean gravitational saddle is not at the Hawking temperature and therefore has a conical singularity at the horizon. Its strategy is to replace the sharp cone by a smooth surface, read off the curvature, and then use the known one-loop effective action on regular manifolds to compute the entropy through the Gibbons-Hawking partition function. In two dimensions it recovers the logarithmic Rindler divergence, finds a finite mass-dependent correction for the eternal black hole, and in four dimensions finds the expected quadratic Rindler divergence plus an extra logarithmic term for Schwarzschild that does not vanish as the mass goes to infinity. The paper argues that these infinities are absorbed by renormalizing the gravitational coupling, so the correction is tied to the coupling that defines the entropy rather than being a disposable artifact of the regulator.

What carries the argument

The load-bearing device is the replacement of the conical metric $ds^2=dρ^2+α^2ρ^2dφ^2$ by a smooth surface embedded in three dimensions, with metric $ds^2=(ρ^2+a^2α^2)/(ρ^2+a^2)dρ^2+α^2ρ^2dφ^2$, and then taking $a→0$. This gives a controlled curvature $R_{con}=2(α-1)αδ(ρ)$, so ordinary determinant and heat-kernel results can be applied. The same device is used to split the four-dimensional Riemann tensor into a conical part plus a regular part, which is what lets the author isolate the extra Schwarzschild term from the regular curvature at the horizon.

Extended reading notes

Core claim

The central claim is that the one-loop quantum correction to a four-dimensional Schwarzschild black hole's entropy is not just the flat Rindler result scaled by horizon area. Using the smoothed-cone regularization, the paper finds a correction of the form $S_q = A_h/(48πϵ^2)$ plus a logarithmic term in $Σ/ϵ$ for a scalar field, where $A_h$ is the horizon area and $ϵ$ is the short-distance regulator. The first term is the quadratic area-law divergence already seen for Rindler space; the logarithmic term survives the infinite-mass limit and is therefore tied to the black hole's topology and to the regular curvature at the horizon rather than to horizon area alone. In two dimensions the same method gives the logarithmic Rindler divergence and a finite, mass-dependent correction for the eternal black hole. The paper's broader claim is that the $L^2$ divergence is removed by renormalizing the gravitational constant, $κ^{-1}=κ_B^{-1}+L^2$, and the logarithmic divergence by a curvature-squared coupling, so the entropy's infinities track the renormalization of gravitational couplings.

Load-bearing premise

The load-bearing premise is that the distance $ϵ$ from the cone tip can be identified with the inverse ultraviolet cutoff $L^{-1}$, so that one short-distance scale does both jobs; the paper calls this natural and checks it against a zeta-function calculation, but every divergent coefficient and the renormalization argument are stated in units set by that identification.

Editorial extensions

If this is right

  • The leading Rindler divergence is reproduced in both dimensions: logarithmic in 2D and quadratic in 4D, supporting the use of flat Rindler space for the dominant horizon contribution.
  • The eternal 2D black hole acquires a finite, mass-dependent entropy correction, so its thermodynamic temperature defined by $∂_M S$ is shifted from the Hawking temperature.
  • For 4D Schwarzschild, the entropy has a logarithmic term that survives $M→∞$, so the infinite-mass limit does not reduce the full entropy to the Rindler result.
  • The $L^2$ divergence of the entropy is absorbed by $κ^{-1}=κ_B^{-1}+L^2$, and the logarithmic divergence by a curvature-squared coupling, tying entropy renormalization to gravitational coupling renormalization.
  • Quantum corrections remain proportional to horizon area at leading order but include a subleading term controlled by topology and horizon curvature.

Reading between the lines

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

  • If the extra logarithmic term is regulator-independent, horizon area alone cannot fix black-hole entropy even asymptotically; a subleading topological or curvature piece would have to be reproduced by any state-counting derivation.
  • Because the term is mass-independent while the area term scales as $M^2$, it would dominate the entropy of sufficiently small black holes; if the one-loop treatment survives there, late-stage evaporation thermodynamics would be modified.
  • The smoothed-cone picture suggests a concrete numerical check: vary the core radius $a$ of the regularized cone and see whether the entropy coefficient is stable before taking $a→0$.
  • The renormalization pattern hints that a microscopic theory should predict the finite constant left after the gravitational couplings are renormalized, since the divergent part alone does not fix the entropy.
Original abstract

For general finite temperature different from the Hawking one there appears a well known conical singularity in the Euclidean classical solution of gravitational equations. The method of regularizing the cone by regular surface is used to determine the curvature tensors for such a metrics. This allows one to calculate the one-loop matter effective action and the corresponding one-loop quantum corrections to the entropy in the framework of the path integral approach of Gibbons and Hawking. The two-dimensional and four-dimensional cases are considered. The entropy of the Rindler space is shown to be divergent logarithmically in two dimensions and quadratically in four dimensions that coincides with results obtained earlier. For the eternal 2D black hole we observe finite, dependent on the mass, correction to the entropy. The entropy of the 4D Schwarzschild black hole is shown to possess an additional (in comparison with the 4D Rindler space) logarithmically divergent correction which does not vanish in the limit of infinite mass of the black hole. We argue that infinities of the entropy in four dimensions are renormalized by the renormalization of the gravitational coupling.

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, 6,269 input tokens, $0.0003 reported.

What the abstract itself states, as probabilities: claims first 0.04 · states limitation 0.24 · human participants 0.01 · controlled comparison 0.25 · randomized assignment 0.01 · states quantitative result 0.33 · compares with prior results 0.94 · mentions code or data availability 0.01.

The abstract, sentence by sentence

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

For general finite temperature different from the Hawking one there appears a well known conical singularity in the Euclidean classical solution of gravitational equations. The method of regularizing the cone by regular surface is used to determine the curvature tensors for such a metrics. This allows one to calculate the one-loop matter effective action and the corresponding one-loop quantum corrections to the entropy in the framework of the path integral approach of Gibbons and Hawking. The two-dimensional and four-dimensional cases are considered. The entropy of the Rindler space is shown to be divergent logarithmically in two dimensions and quadratically in four dimensions that coincides with results obtained earlier. For the eternal 2D black hole we observe finite, dependent on the mass, correction to the entropy. The entropy of the 4D Schwarzschild black hole is shown to possess an additional (in comparison with the 4D Rindler space) logarithmically divergent correction which does not vanish in the limit of infinite mass of the black hole. We argue that infinities of the entropy in four dimensions are renormalized by the renormalization of the gravitational coupling.

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 For general finite temperature different from the Hawking one there appears a well known conical singularity in the Euclidean classical solution of gravitational equations. background 1.00 0.07 0.03 asserted 1.00
s1 The method of regularizing the cone by regular surface is used to determine the curvature tensors for such a metrics. method 0.99 0.73 0.02 asserted 0.98
s2 This allows one to calculate the one-loop matter effective action and the corresponding one-loop quantum corrections to the entropy in the framework of the path integral approach of Gibbons and Hawking. method 0.93 0.68 0.09 asserted 0.74
s3 The two-dimensional and four-dimensional cases are considered. contribution 0.74 0.64 0.02 asserted 0.77
s4 The entropy of the Rindler space is shown to be divergent logarithmically in two dimensions and quadratically in four dimensions that coincides with results obtained earlier. result 1.00 0.55 0.13 asserted 1.00
s5 For the eternal 2D black hole we observe finite, dependent on the mass, correction to the entropy. result 1.00 0.89 0.12 asserted 0.99
s6 The entropy of the 4D Schwarzschild black hole is shown to possess an additional (in comparison with the 4D Rindler space) logarithmically divergent correction which does not vanish in the limit of infinite mass of the black hole. result 1.00 0.88 0.33 asserted 1.00
s7 We argue that infinities of the entropy in four dimensions are renormalized by the renormalization of the gravitational coupling. interpretation 1.00 0.54 0.50 hedged possibility 0.45

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
  • arXiv listing abstract v1
not examined
  • full text
  • figures and tables
  • references and citing sentences
  • relations to other papers
levels run
  • P abstract
not run
  • 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

81 later papers cite it

Evidence: substantial. 75 of the citing papers share no author with it, and 12 of those carry a confident label from Pith's citation classifier.

Pith read 11 of the 114 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

Uses its method or tool 2 of 9 papers with this label
How the literature uses it

79 arXiv papers cite this in 112 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 · 71 sentences without a confident label

Uses its method or tool 9 papers
Uses its data or values 1 paper
  • In this case $r_-=0$ ($q=0$) and $r_+=2m$ so that the entropy, found by Solodukhin [ref] , is S_Sch=A(Σ)ø48πϵ^2+1ø45lnr_+øϵ . entropy-Sch Historically this was the first time when the subleading logarithmic term in entanglement entropy was computed.

    Entanglement entropy of black holes · The Reissner-Nordström black hole. · 0.88

Compares with it 2 papers
Cites it as support 1 paper
  • There is compelling evidence that this divergence is cancelled by a renormalization of Newton's constant in the area term [ref] .

    Generalized Second Law for Cosmology · Generalized Entropy and Quantum Expansion · 0.96

Cites it as background 26 papers

Discussion

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