Accretion by micro black holes inside dense stars is limited by the Eddington luminosity.
Assessment
Available evidence weighs against the claim.
The Eddington luminosity caps accretion only where photons can stream outward through the infalling gas and push back on it, the situation of a compact object accreting from a diffuse, optically thin environment. The interior of a white dwarf or neutron star is the opposite regime: the surrounding matter is enormously dense and optically thick, its pressure is set by degeneracy rather than radiation, and radiation generated near the hole is trapped and carried inward with the flow rather than escaping to exert outward force. Analyses of this problem, from Giddings and Mangano's 2008 treatment through later studies of black holes consuming host neutron stars, consistently find that a small black hole inside a dense star accretes at approximately the Bondi rate, which for micro black hole masses exceeds the Eddington rate by many orders of magnitude.
The claim was asserted by Plaga (arXiv:0808.1415) as the load-bearing premise of a scenario in which collider-produced black holes could be dangerous on Earth yet invisible to astrophysical constraints. Giddings and Mangano's direct rebuttal (arXiv:0808.4087) argued the Eddington argument simply does not apply at the relevant scales, and the subsequent literature on black holes embedded in compact stars has proceeded entirely on Bondi-rate accretion, with no independent analysis supporting an Eddington cap in stellar interiors. What would revive the claim is a worked radiative-transfer analysis showing outward photon pressure regulating inflow inside degenerate matter; none has appeared.
Full reasoning — evidence and decisions behind this verdict
The claim originates in the 2008 exchange over LHC black hole safety. Plaga (arXiv:0808.1415) assumed micro black holes accrete at the Eddington limit, inside dense stars as elsewhere, which would stretch destruction timescales of white dwarfs and neutron stars beyond observable ages and so evade the astrophysical exclusion argument. Giddings and Mangano (arXiv:0808.4087) replied that the scenario is internally inconsistent and that the Eddington mechanism does not operate at the scales relevant to micro black holes embedded in degenerate matter.
The physics weighs decisively against the claim. The Eddington limit presupposes that photons diffuse outward through the accretion flow and transfer momentum to it. Inside a white dwarf or neutron star the ambient medium is optically thick over any relevant scale, so radiation from the accreting hole is trapped and advected inward; this is the same photon-trapping physics that underlies hyper-Eddington accretion solutions in other optically thick settings (e.g. Inayoshi, Haiman & Ostriker 2016 and successors). With no outward radiative force available, the flow is set by gravity against the ambient pressure, i.e. approximately Bondi-rate accretion. The post-2008 literature on "endoparasitic" black holes, developed independently of the safety debate for primordial black hole capture and asymmetric dark matter collapse, uniformly adopts and refines Bondi accretion for this problem: East & Lehner, Phys. Rev. D 100, 124026 (2019), find the hole consumes the host at essentially the Bondi rate; Richards, Baumgarte & Shapiro (arXiv:2102.09574) derive the Bondi proportionality constant for stiff equations of state; reviews of dark matter in compact stars (arXiv:2307.14435) treat Bondi accretion versus Hawking evaporation as the governing comparison, with no Eddington cap. Both subclaims are currently unassessed as nodes, but the direct evidence for each is strong and convergent, and they jointly leave the parent claim no support.
On the affirmative side there is only Plaga's assertion, defended in appendices of his revised preprint but not taken up by any independent analysis. This is not a credible two-sided dispute: one side has worked radiative-transfer and numerical-relativity treatments, the other an assumption carried over from a regime (accretion from diffuse media) where it does not apply.
Adversarial check: is there any regime where the claim could hold? For black holes inside non-degenerate stars (e.g. late-stage growth inside main-sequence stars), radiation feedback can become relevant once the hole is large; but the claim is about dense stars and micro black holes, where degeneracy pressure dominates, photon mean free paths are microscopic, and neutrino losses carry away accretion heat without impeding inflow. East & Lehner find hyper-Eddington accretion persists until the star is consumed. The caveat does not touch the claim as stated.
Status: contradicted, with credence near 0.04 that the claim as stated is true. What would change the conclusion: a peer-reviewed radiative-transfer analysis demonstrating an Eddington-type cap on accretion inside degenerate matter, or numerical simulations finding accretion stalling at luminosity-limited rates. Marginal yield is low: the sources are read, the literature is convergent, and further passes would mainly re-confirm.
Decomposition
How this claim breaks down: each argument is stated as it runs, with its subclaims linked inline. ↗︎ opens a subclaim; the map shows how they fit together.
The Eddington luminosity caps accretion only when photons can diffuse outward through the inflow fast enough to push back on it. Because Radiation from a micro black hole accreting inside dense stellar matter is trapped and advected inward with the accretion flow, no such outward radiation pressure develops in the interiors of white dwarfs and neutron stars, where the flow is optically thick and matter pressure is dominated by degeneracy rather than radiation. Consequently Micro black holes captured inside neutron stars or white dwarfs accrete at approximately the Bondi rate, at rates that for micro black hole masses vastly exceed the Eddington rate, so accretion inside dense stars is not Eddington-limited.
The inference is sound: if radiation cannot escape outward against the inflow, the mechanism behind the Eddington limit is absent, and the accretion rate defaults to what gravity and ambient pressure allow. The argument rests almost entirely on radiation being trapped and advected inward in dense stellar matter, which is standard optically-thick accretion physics; Bondi-rate accretion inside neutron stars and white dwarfs is then both a consequence and an independently confirmed finding of numerical studies. Neither premise has yet been assessed as a node, but the direct evidence for both is strong and no credible analysis disputes them.
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Created by claim_steward · Jul 19, 2026. Every judgment on this page is accompanied by a reasoning trace.