REVIEW
Will black holes eventually engulf the universe?
Astrophysics · Submitted 28 Mar 2006 · 17 references
Pith's verdict: A plausible extension of the BDE accretion result to time-dependent black-hole metrics, with a solid asymptotic estimate, but the universal 'never engulfs' conclusion rests on a hand-wavy holographic argument that does not actually exclude the critical mass.
T0 · AI review
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Referee report
The paper
The paper claims
This paper argues that black holes accreting quintessence dark energy with w > -1 cannot grow fast enough to engulf the universe, because the asymptotic growth factor is bounded near 10^-23 times the initial mass in solar units.
The reading
What carries the argument
The load-bearing object is the generalized mass-accretion equation for a Schwarzschild metric whose mass depends on time, $M(t)$. Solving the conservation laws for a perfect-fluid dark energy gives $\dot{M} = 4\pi A' M^2 (p+\rho) e^{-\int_r^\infty f(r,t) dr}$, which in the limit $r\to\infty$ reduces to the Babichev–Dokuchaev–Eroshenko form. The decisive quantity is then the denominator factor $F(t)$ in $M = M_0/[1-F(t)]$; its finite asymptote $(8\pi\rho_0/3)^{1/2} A' M_0$ controls the maximum possible growth and evaluates to $X_0 10^{-23}$ for $M_0 = X_0 M_\odot$.
Extended reading notes
Core claim
The central claim is that the accretion rate asymptotically has the same form as in the static case, $\dot{M} = 4\pi A' M^2(\rho_\infty + p_\infty)$, even when the black-hole mass is allowed to depend on time in the Schwarzschild metric. The explicit solution $M = M_0/[1-F(t)]$ has an increasing denominator factor $F(t)$ that tends to the finite value $(8\pi\rho_0/3)^{1/2} A' M_0$ rather than diverging, so no finite-time blow-up occurs. Using current measurements of the Hubble constant, about $10^{-26}$ inverse meters, the asymptotic growth factor is $\sim X_0 10^{-23}$ for an initial mass $M_0 = X_0 M_\odot$, orders of magnitude below unity even for $X_0 = 10^{10}$. The paper therefore claims that engulfing is forbidden for all physically realized black holes in quintessential models, with the 'never' step resting on the holographic entropy bound.
Load-bearing premise
The conclusion that engulfing could 'never' occur rests on applying the holographic entropy bound to the whole universe and on the assertion that distant receding black holes can never coalesce; if either premise fails, the accretion calculation only shows known black holes grow negligibly, not that all black holes are forever barred from engulfing.
Editorial extensions
If this is right
- For every observed black hole, from stellar-mass to $10^{10}$ solar-mass supermassive holes, dark-energy accretion produces a mass increase far below unity, so the growth is too slow to be observed.
- The original big-swell scenario survives in the asymptotic rate equation but is rendered harmless by the finite upper bound on $F(t)$.
- Only initial masses near $10^{23}$ solar masses, comparable to the total mass of the universe, could in principle lead to engulfing, and the paper's entropy-bound argument rules those out.
- If the dark-energy equation of state stays above $w=-1$, the future growth of black holes is set by ordinary accretion and Hawking evaporation, not by runaway dark-energy accretion.
Reading between the lines
- Editorial inference: the finite bound $X_0 10^{-23}$ means dark-energy accretion is observationally irrelevant for black-hole mass evolution; merger rates and ordinary gas accretion, not dark energy, will set the masses of the largest black holes.
- Editorial inference: the 'never' step assumes distant black holes never coalesce; in a universe with large-scale structure growth producing repeated mergers, the entropy-bound argument would need a separate test.
- Editorial inference: the asymptotic rate being independent of metric staticity suggests the same small-growth bound should hold for more general dynamical black-hole spacetimes, which numerical relativity simulations could verify.
- Editorial inference: if future data show $w$ crossing $-1$, the sign of $p+\rho$ flips and the accretion equation changes character, so the no-engulfing result is specific to non-phantom quintessence.
Original abstract
The Babichev-Dokuchaev-Eroshenko model for the accretion of dark energy onto black holes has been extended to deal with black holes with non-static metrics. The possibility that for an asymptotic observer a black hole with large mass will rapidly increase and eventually engulf the Universe at a finite time in the future has been studied by using reasonable values for astronomical parameters. It is concluded that such a phenomenon is forbidden for all black holes in quintessential cosmological models.
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
The Babichev-Dokuchaev-Eroshenko model for the accretion of dark energy onto black holes has been extended to deal with black holes with non-static metrics. The possibility that for an asymptotic observer a black hole with large mass will rapidly increase and eventually engulf the Universe at a finite time in the future has been studied by using reasonable values for astronomical parameters. It is concluded that such a phenomenon is forbidden for all black holes in quintessential cosmological models.
background contribution method result interpretation main claim
| # | sentence | role | the authors' own work | states the main conclusion | strength |
|---|---|---|---|---|---|
| s0 | The Babichev-Dokuchaev-Eroshenko model for the accretion of dark energy onto black holes has been extended to deal with black holes with non-static metrics. | contribution 0.79 | 0.78 | 0.03 | asserted 1.00 |
| s1 | The possibility that for an asymptotic observer a black hole with large mass will rapidly increase and eventually engulf the Universe at a finite time in the future has been studied by using reasonable values for astronomical parameters. | contribution 0.79 | 0.64 | 0.08 | hedged possibility 0.88 |
| s2 | It is concluded that such a phenomenon is forbidden for all black holes in quintessential cosmological models. | result 0.98 | 0.85 | 0.94 | asserted 1.00 |
What was examined, and what was not
- arXiv listing abstract v1
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- P abstract
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References
How the literature uses it
5 arXiv papers cite this in 15 sentences
Papers citing it · 13 sentences without a confident label
Contests it 1 paper
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The reason is that Eq.([ref]) in [ref] is obtained under the assumption [equation] From Eq.([ref]), we know the assumption for the solution used in this paper is unreasonable.
Dark Energy Accretion onto a Black Hole in an Expanding Universe · Discussion and Conclusion · contest 0.88
Cites it as background 1 paper
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General discussion concerning evaporation/accretion models involving both regular black holes and traversable wormholes can be found in references [ref] .
From black-bounce to traversable wormhole, and beyond · Vaidya black-bounce · 0.99
Discussion
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