REVIEW
Overcharging a Black Hole and Cosmic Censorship
General Relativity and Quantum Cosmology · Submitted 17 Aug 1998 · 17 references
Pith's verdict: A real new observation (near-extremal, not extremal, starting point) plus a clean shell no-go, wrapped in an abstract that promises more than the body delivers — and the body knows it.
T0 · AI review
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Referee report
The paper
The paper claims
A single charged particle can, in the test-particle limit, drive a near-extremal Reissner-Nordström black hole past extremality, but the paper's own self-force estimate makes the particle bounce short of the horizon, leaving the censorship
The reading
What carries the argument
The load-bearing object is the radial equation of motion for a charged test particle in ingoing Eddington coordinates, $dot r^2 = frac{1}{m^2}[E + qA_v(r)]^2 - g(r)$ with $A_v = -Q/r$ and $g(r) = 1 - 2M/r + Q^2/r^2$. Capture requires $dot r^2 > 0$ for all $r ge r_+$; overcharging requires $E < Q+q-M$. Combining the two gives a lower bound on the particle charge, $q > r_+ - Q^2$, which is empty at extremality and nonempty just below it. That inequality is the whole mechanism: it says the extremal no-go is a knife-edge case, not a barrier. The second piece of machinery is the epsilon-scaling ansatz that turns the three conditions into a single small parameter, letting the author display simultaneously the $O(e^2)$ capture margin, the $O(e)$ self-force corrections taken from the Quinn-Wald equation, and the $O(e)$ classical radius. For the shell case the analogous object is the junction equation $sqrt{g_{in}+dot R^2} - sqrt{g_{out}+dot R^2} = -m/R$, whose effective potential contains the shell's own self-repulsion and self-attraction terms.
Extended reading notes
Core claim
The paper's central claim is conditional and stated as such: if backreaction can be neglected, a near-extremal Reissner-Nordström black hole can be overcharged by a single charged particle. The construction is explicit. With $M=1$, $Q=1-2e^2$, and particle parameters $q=ae$, $E=ae-2be^2$, $m=ce$ for $a>1$, $1<b<a$, $c<sqrt(a^2-b^2)$, the test-particle radial equation gives $dot r^2(r_m) > 0$ at leading order, so the particle passes $r_+$, and $(M+E)-(Q+q) = -2(b-1)e^2 < 0$, so the final configuration exceeds extremality. The same scaling makes the particle's classical radius $q^2/m = a^2 e/c$ and the relative size of the Quinn-Wald self-force terms arbitrarily small as $e to 0$. The paper is explicit that this does not settle the question. The capture margin is $O(e^2)$ while the radiation-damping correction is $O(e)$, so the correction is not small compared with the margin; the single numerical example ($Q=0.99999$, $q=3times10^{-3}$, $m=1.8times10^{-3}$, $E=2.9897times10^{-3}$) shows the corrected $dot r^2$ turning negative, i.e. a bounce. A 'best case' rescue in which all radiated energy escapes requires a starting energy of about $0.0122$ and appears to allow capture, but the author notes the linearized energy integral is unreliable near the horizon, where the correction ratio grows like $e^2/(r-1)^2$ and reaches order one. The companion shell calculation is exact and negative: for an imploding charged shell, the condition $dot R^2(r_m)>0$ is algebraically incompatible with overcharging, and the less stringent condition $d dot R^2/dr(r_+)>0$ is incompatible with the physical bound $0<m^2<E^2$, so the shell bounces outside the horizon.
Load-bearing premise
The argument needs the neglected self-force terms to be negligible for the outcome, but the paper's own scaling shows the capture margin shrinks faster than the corrections do, so smallness relative to the leading terms does not deliver smallness relative to what the process has to overcome.
Editorial extensions
If this is right
- The extremal no-go for charged-particle capture is not a barrier but a limiting case: any black hole even slightly below extremality admits a finite window of particle charges and energies that overshoot the bound in the test limit.
- Whether cosmic censorship survives in this scenario cannot be decided by comparing the size of backreaction terms to the size of the leading terms; the relevant comparison is to the capture margin, and the paper's own scaling shows the margin loses.
- For a charged imploding shell, censorship is upheld without approximation, because the shell's electromagnetic self-repulsion prevents it from crossing the horizon whenever the parameters would overcharge the hole.
- Any claim that a near-extremal hole can be destroyed must specify the fate of the energy radiated during the infall, since the final mass depends on how much of that radiation is recaptured.
Reading between the lines
- The paper's structure suggests a general lesson for gedanken experiments: an experiment whose success margin scales as one power of a small parameter higher than its own error terms is undecidable at that order, and the honest verdict is 'not resolved' rather than either 'censorship holds' or 'censorship fails'.
- The contrast between the point particle and the shell points to a one-parameter family interpolating between them, a ring of $N$ symmetrically placed particles, where self-repulsion is diluted by a factor of order $N$ while self-force corrections persist; the paper reports exploratory checks for $N=2,4,6$ but does not settle the backreaction question there.
- The uncharged rotating analogue, a spinning particle dropped into a near-extremal Kerr hole, removes the electromagnetic self-force that dominates the obstruction here and would be a cleaner place to look for a definite answer.
- If the bounce found in the worked example is generic rather than an artifact of the linearized energy integral, then the near-horizon energy loss acts as a self-regulating mechanism that keeps the horizon intact without any appeal to a new principle.
Original abstract
We show that, contrary to a widespread belief, one can overcharge a near extremal Reissner-Nordstrom black hole by throwing in a charged particle, as long as the backreaction effects may be considered negligible. Furthermore, we find that we can make the particle's classical radius, mass, and charge, as well as the relative size of the backreaction terms arbitrarily small, by adjusting the parameters corresponding to the particle appropriately. This suggests that the question of cosmic censorship is still not wholly resolved even in this simple scenario. We contrast this with attempting to overcharge a black hole with a charged imploding shell, where we find that cosmic censorship is upheld. We also briefly comment on a number of possible extensions.
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 show that, contrary to a widespread belief, one can overcharge a near extremal Reissner-Nordstrom black hole by throwing in a charged particle, as long as the backreaction effects may be considered negligible. Furthermore, we find that we can make the particle's classical radius, mass, and charge, as well as the relative size of the backreaction terms arbitrarily small, by adjusting the parameters corresponding to the particle appropriately. This suggests that the question of cosmic censorship is still not wholly resolved even in this simple scenario. We contrast this with attempting to overcharge a black hole with a charged imploding shell, where we find that cosmic censorship is upheld. We also briefly comment on a number of possible extensions.
background contribution method result interpretation main claim
| # | sentence | role | the authors' own work | states the main conclusion | strength |
|---|---|---|---|---|---|
| s0 | We show that, contrary to a widespread belief, one can overcharge a near extremal Reissner-Nordstrom black hole by throwing in a charged particle, as long as the backreaction effects may be considered negligible. | result 0.99 | 0.92 | 0.89 | asserted 0.92 |
| s1 | Furthermore, we find that we can make the particle's classical radius, mass, and charge, as well as the relative size of the backreaction terms arbitrarily small, by adjusting the parameters corresponding to the particle appropriately. | result 0.99 | 0.95 | 0.09 | asserted 0.99 |
| s2 | This suggests that the question of cosmic censorship is still not wholly resolved even in this simple scenario. | interpretation 1.00 | 0.31 | 0.48 | hedged possibility 1.00 |
| s3 | We contrast this with attempting to overcharge a black hole with a charged imploding shell, where we find that cosmic censorship is upheld. | result 0.98 | 0.94 | 0.07 | asserted 1.00 |
| s4 | We also briefly comment on a number of possible extensions. | future work 0.97 | 0.53 | 0.02 | unclear 0.91 |
What was examined, and what was not
- arXiv listing abstract v1
- full text
- figures and tables
- references and citing sentences
- relations to other papers
- P abstract
- S sections
- T body sentences
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- R cross-paper relations
Figures
Figures reproduced from arXiv:gr-qc/9808043 by the authors.
References
How later papers used it
76 later papers cite it
1 later paper by other authors is listed below: 1 built on it.
Builds on it 1 of 2 papers with this label
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Generalized the analysis constructed for Reissner-Nordstrom black holes by this paper.
Charged spherically symmetric black holes in the Lyra geometry and a preliminary investigation on the overcharging process (2024) · 1.00 · paraphrased: the licence does not allow quoting
How the literature uses it
61 arXiv papers cite this in 102 sentences
Papers citing it · 61 sentences without a confident label
Contests it 2 papers
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To reconcile these conflicting results, Sorce and Wald (SW) [ref] showed that the linear-order analysis in Hubeny's gedankenexperiment [ref] was insufficient, as the potential violation in the near-extremal expansion must be of the second order [ref] .
Weak Cosmic Censorship Conjecture in Gedanken Experiments at All Orders · Introduction · contest 0.80
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This work has put all the Hubeny type of (classical) gadanken experiments [ref] into question.
Quasi-normal Modes of near-extremal black holes in Generalized spherically symmetric spacetime and Strong Cosmic Censorship Conjecture · An exotic near-extremal black hole and Creation of over-extremal spacetime, a naked singularity · contest 0.71
Builds on it 1 paper
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The equations of motion for charged timelike shells in asymptotically flat black hole backgrounds were previously studied in [ref] and here we generalize them to the asymptotically AdS case.
Bouncing inside the horizon and scrambling delays · Massive charged shell · 0.99
Uses its method or tool 1 paper
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Following [ref] , we define the minimum possible value of $δM$ given by the requirement that particle falls into the star which is given by
Extending the weak cosmic censorship conjecture to the charged Buchdahl star by employing the gedanken experiments · Perturbation inequalities and gedanken experiment · 0.88
Uses its data or values 1 paper
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So for the given background spacetime with parameters $M=1$ and $Q=0.99999$ as stated in [ref] , we can then select the appropriate parameters of the charged particle by setting $α'=1.33902$, $β'=1.0301$, and $γ'=0.80505$.
Overcharging process around a magnetized black hole: Can the backreaction effect of magnetic field restore cosmic censorship conjecture? · Overcharging of Reissner-Nordström black hole · 0.86
Compares with it 5 papers
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In contrast to the finding that neither a test charged particle nor a charged scalar field can destroy an extremal Reissner-Nordström black hole [ref] , we demonstrate that both a test particle and a charged scalar field can overcharge an extremal nonsingular ABG black hole at linear order, owing to nonlinear electrodynamic field corrections.
Overcharging a nonsingular black hole in general relativity: the nonlinear electrodynamic field effects · Conclusion and Discussion · 0.95
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Notice that the restriction ([ref]) is exactly the same obtained previously for the classical gedanken experiments involving charged test bodies, see [ref] .
Challenging the weak cosmic censorship conjecture with charged quantum particles · Challenging the WCCC · 0.96
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Although the back reaction effects are completely neglected, the analysis in Ref. [ref] is in sharp contrast with previous works [ref] .
Cosmic censorship in overcharging a Reissner-Nordstr\"{o}m black hole via charged particle absorption · Test particle case · 0.85
Cites it as background 26 papers
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It is well known [ref] that the RN black hole can be overcharged and thus the WCCC is violated for linear accretion process while it would always be restored when non-linear order perturbations are included.
Testing the weak cosmic censorship conjecture for a Reissner-Nordstr\"{o}m-de Sitter black hole surrounded by perfect fluid dark matter · Conclusions · 0.84
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We briefly review the basic idea of overcharging a RN black hole by the infall of a charged particle, giving the precise meaning of “overcharging”, based on the discussion in Ref. [ref] .
Cosmic censorship in overcharging a Reissner-Nordstr\"{o}m black hole via charged particle absorption · Overcharging a Reissner-Nordström black hole without back reaction effects · 0.97
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Another avenue for violating cosmic censorship was identified by Hubeny [ref] , who noticed that a near-extremal Reissner-Nordström black hole, possessing a charge $Q$ that is almost as large as its mass $M$ (in geometrized units in which $G = c = 1$), can absorb a test particle of such charge $q$, mass $m$, and energy $E_0$ that the final configuration cannot be a black hole: the final charge $Q + q$ exceeds the final mass $M + E_0$, signalling the presumed destruction of the event horizon.
Self-force as a cosmic censor · Introduction · 0.86
Discussion
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