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arxiv: 2605.26204 · v2 · pith:5SUC4QEEnew · submitted 2026-05-25 · ✦ hep-ph · astro-ph.CO· astro-ph.HE

Electromagnetic Signatures From Primordial Black Holes in the Solar System

Alexandra P. Klipfel , David I. Kaiser This is my paper

Pith reviewed 2026-06-29 21:14 UTC · model grok-4.3

classification ✦ hep-ph astro-ph.COastro-ph.HE
keywords primordial black holesdark matterHawking radiationsolar systemgamma-ray detectionultrahigh energy neutrinostransit ratesasteroid mass range
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The pith

Calculations show that instruments like AMEGO-X could detect Hawking radiation from primordial black holes transiting within 0.1 AU of Earth, while HAWC and LHAASO could observe their explosions out to 0.1 and 0.5 parsecs.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper computes the rates at which asteroid-mass primordial black holes would transit the inner solar system or explode at its outer edges if their extended mass distributions account for all dark matter. It then determines the distances at which several ground- and space-based photon detectors could register the resulting electromagnetic signals across radio to ultrahigh-energy gamma-ray bands. A sympathetic reader would care because positive detections would offer a direct test of whether these black holes constitute dark matter, while null results would constrain their allowed abundance and mass range. The analysis also evaluates whether a proposed primordial black hole explosion at roughly 1000 AU could have produced an observable electromagnetic counterpart to a recent ultrahigh-energy neutrino event.

Core claim

By evaluating local transit rates for extended primordial black hole mass distributions that could comprise all the dark matter, the authors establish that the proposed AMEGO-X satellite could reliably detect Hawking-radiated photons from transits within O(0.1 AU) of Earth, while the HAWC and LHAASO observatories are sensitive to explosions out to O(0.1 pc) and O(0.5 pc) respectively. They further show that a future explosion at a distance of about 10^3 AU could yield measurable electromagnetic signals at Earth depending on alignment with detector fields of view, although the specific 2023 KM3NeT neutrino event would not have produced detectable signals given its sky position and the offline

What carries the argument

Hawking radiation photon spectra from asteroid-mass primordial black holes, combined with computed local transit rates and explosion frequencies for extended mass distributions.

If this is right

  • The AMEGO-X satellite could detect electromagnetic signals from primordial black hole transits within O(0.1 AU) of Earth.
  • HAWC could register primordial black hole explosions out to O(0.1 pc).
  • LHAASO could register primordial black hole explosions out to O(0.5 pc).
  • Future primordial black hole explosions at distances around 10^3 AU could produce measurable electromagnetic signals if aligned with active detector fields of view.
  • The 2023 KM3NeT neutrino event at ~10^3 AU would not have produced detectable electromagnetic signals due to sky position and HAWC status.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Non-detections across these instruments would tighten upper limits on the fraction of dark matter that can reside in asteroid-mass primordial black holes.
  • Positive detections would allow reconstruction of the local primordial black hole mass distribution from the observed photon spectra and event rates.
  • This electromagnetic channel could be combined with gravitational-wave or microlensing searches to cross-check whether primordial black holes explain isolated high-energy neutrino events.
  • Alignment requirements for distant explosions imply that coordinated multi-instrument campaigns would increase the chance of capturing both electromagnetic and neutrino signals from the same event.

Load-bearing premise

Extended mass distributions of asteroid-mass primordial black holes can comprise all the dark matter, which fixes the local transit rates and explosion frequencies used to derive the quoted detection distances.

What would settle it

A null result from a multi-year search for transit or explosion signatures with AMEGO-X, HAWC, or LHAASO at the predicted rates would indicate that such primordial black holes do not make up all the dark matter.

Figures

Figures reproduced from arXiv: 2605.26204 by Alexandra P. Klipfel, David I. Kaiser.

Figure 1
Figure 1. Figure 1: (Left) Primary photon Hawking emission spectra for Schwarzschild black holes with masses ranging from 1017 g (yellow) to 1024 g (black). (Right) Secondary Hawking emission spectra for PBHs with masses ranging from 1013 g (yellow) to 1020 g (black). Plots prepared with BlackHawk v2.2 [38, 39]. which are space-based detectors sensitive to UV and X-ray bands, respectively. Finally, in Section III D we briefly… view at source ↗
Figure 2
Figure 2. Figure 2: Constraints on PBH dark matter fraction [PITH_FULL_IMAGE:figures/full_fig_p005_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: (Left) Cumulative inner Solar System transit rates for PBHs with mass m ≤ M expected to pass within 5 AU of the Earth per year, according to Eq. (18). The peak of the number distribution is fixed at M¯ = 5 × 1017 g. (Right) Total PBH transit rates for impact parameters b ≤ 5 AU as a function of population peak mass M¯ and model parameters α and β, computed with Eq. (19). We consider transit rates for the s… view at source ↗
Figure 5
Figure 5. Figure 5: Measured photon count rate given by Eq. ( [PITH_FULL_IMAGE:figures/full_fig_p007_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: Maximum detectable impact parameter bmax as a function of PBH mass for a PBH stationary relative to the GALEX detector. The PBH masses that maximize the curves are MNUV max = 1.01 × 1022 g (b NUV max = 2.5 × 106 m) and MFUV max = 7.34 × 1021 g (b FUV max = 1.1 × 107 m). where ψ ∈ [0, 2π)is a randomly sampled phase. We are work￾ing in Cartesian coordinates centered on the Earth with the equator lying in the… view at source ↗
Figure 7
Figure 7. Figure 7: Emission rate of detectable photons in the four en￾ergy bins ∆Ek expected for the proposed AMEGO-X experi￾ment computed by integrating the secondary spectra shown in [PITH_FULL_IMAGE:figures/full_fig_p009_7.png] view at source ↗
Figure 8
Figure 8. Figure 8: Simulated transit signal with parameters [PITH_FULL_IMAGE:figures/full_fig_p011_8.png] view at source ↗
Figure 9
Figure 9. Figure 9: Probability of PBH transit detection Pdet(b|M) for AMEGO-X as a function of impact parameter b and PBH mass M, from Eq. (42). We assume four values of the SNR threshold sensitivity Sthresh, assuming that detection of transit events with Sthresh < 1 will be possible with matched filtering, as demonstrated in our previous work [19]. Each point is computed with n = 103 simulations. The maximum impact paramete… view at source ↗
Figure 10
Figure 10. Figure 10: Emitted power by a PBH of mass M in the ra￾dio band 10 MHz ≤ f ≤ 1 THz described in Table VI. The vertical black line corresponds to the critical mass Mc = 1.26 × 1027, such that all PBHs with mass M ≤ Mc are net emitters. Note that the upper edge of the asteroid mass win￾dow is M ∼ 1023 g. These signals are exponentially too weak to detect. For example, assuming a 70 m diameter dish with a sensitivity of… view at source ↗
Figure 11
Figure 11. Figure 11: Secondary photon emission spectra for PBHs with [PITH_FULL_IMAGE:figures/full_fig_p014_11.png] view at source ↗
Figure 12
Figure 12. Figure 12: Detectable photon emission rate as a function [PITH_FULL_IMAGE:figures/full_fig_p015_12.png] view at source ↗
Figure 13
Figure 13. Figure 13: Measured signal photon counts Nsig(b, θ) for a PBH explosion a distance b from Earth with duration τburst = 10 s and zenith angle θ, for the LHAASO-WCDA detector (left) and for HAWC (right). Both instruments are less sensitive to bursts farther from the zenith θ = 0. The vertical black line indicates b = 1890 AU, the estimated distance for an explosion which could theoretically have sourced the KM3NeT eve… view at source ↗
Figure 14
Figure 14. Figure 14: Expected photon signal counts (dark blue line) and [PITH_FULL_IMAGE:figures/full_fig_p018_14.png] view at source ↗
read the original abstract

Primordial black holes (PBHs) in the asteroid-mass range, with typical masses $10^{17}\,{\rm g}\lesssim M \lesssim 10^{23}\,{\rm g}$, have drawn significant recent attention as a viable dark matter candidate. The peak frequencies of photons emitted via Hawking radiation from asteroid-mass PBHs range from infrared to $\gamma$-ray bands. We calculate expected local transit rates for extended PBH mass distributions which could comprise all the dark matter. We evaluate prospects for detecting Hawking-radiated photons from local PBH transits through the inner Solar System and from PBH explosions in the far outer edges of the Solar System. We consider several existing and proposed ground-based and space-based instruments sensitive to photons from the radio band to ultrahigh energy $\gamma$-rays. We find that proposed instruments, such as the AMEGO-X satellite, could reliably detect PBH transits within ${\cal O} (0.1 \, {\rm AU})$ of the Earth, while the HAWC and LHAASO observatories are both sensitive to PBH explosions out to ${\cal O}(0.1 \, {\rm pc})$ and ${\cal O}(0.5 \, {\rm pc})$ respectively. We conclude by specifically considering potential companion electromagnetic signatures in the case of a PBH explosion about $10^3\,{\rm AU}$ from Earth, which has been suggested as a potential source for the $\sim 220 \, {\rm PeV}$ ultrahigh-energy KM3-230213A neutrino event observed by the KM3NeT collaboration in 2023. Whereas we find that the recent KM3NeT event would not have yielded detectable electromagnetic signals -- due to its location on the sky, proposed distance from Earth, and the offline status of the HAWC observatory at that time -- we demonstrate that future PBH explosions at comparable distances could yield measurable electromagnetic signals at Earth, depending on alignment of the PBH burst with detector fields of view.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

0 major / 3 minor

Summary. The manuscript calculates expected local transit rates for asteroid-mass primordial black holes (10^17 g ≲ M ≲ 10^23 g) under extended mass distributions that could comprise all dark matter. It evaluates detection prospects for Hawking-radiated photons from PBH transits in the inner Solar System and explosions in the outer Solar System across instruments spanning radio to ultrahigh-energy gamma rays. The central results state that AMEGO-X could reliably detect transits within O(0.1 AU) of Earth, while HAWC and LHAASO are sensitive to explosions out to O(0.1 pc) and O(0.5 pc), respectively. The paper additionally analyzes potential electromagnetic signatures for a PBH explosion at ~10^3 AU, including in connection with the KM3NeT KM3-230213A neutrino event.

Significance. If the results hold, the work supplies concrete, instrument-specific detection horizons grounded in standard Hawking radiation calculations and published instrument sensitivities. This provides a clear bridge from PBH theory to observational strategy, enabling targeted searches or constraints on asteroid-mass PBH dark matter with existing and proposed facilities. The forward nature of the per-event signal-to-threshold calculations (independent of overall normalization) is a strength.

minor comments (3)
  1. [Abstract] Abstract: the central numerical claims (O(0.1 AU), O(0.1 pc), O(0.5 pc)) are stated without any reference to the underlying luminosity-threshold equating step or mass-distribution normalization; adding one sentence summarizing the key inputs would improve accessibility without lengthening the abstract.
  2. [Abstract] Abstract: the order-of-magnitude notation appears as 'O (0.1 AU)' with italic O and inconsistent spacing; standardizing to \mathcal{O}(0.1\,{\rm AU}) throughout would improve typographic consistency.
  3. The discussion of the KM3NeT event references detector status, sky position, and distance but does not tabulate these parameters; a short table would make the non-detection argument and future-prospect comparison easier to follow.

Simulated Author's Rebuttal

0 responses · 0 unresolved

We thank the referee for their positive assessment of the manuscript, including the recognition of its concrete detection horizons and the strength of the per-event signal calculations. The recommendation for minor revision is noted. No specific major comments were provided in the report.

Circularity Check

0 steps flagged

No significant circularity

full rationale

The paper's central claims (instrument reach distances for PBH transits and explosions) are derived from forward calculations equating standard Hawking luminosity/fluence formulas to detector thresholds and effective areas. The extended mass distribution assumption normalizes local number density and thus event rates, but does not enter the per-event signal-to-threshold step that sets the quoted O(0.1 AU) or O(0.1-0.5 pc) distances. No equations reduce by construction to fitted parameters, no self-citation chains justify uniqueness or ansatze, and no renaming of known results occurs. The derivation is self-contained against external benchmarks.

Axiom & Free-Parameter Ledger

0 free parameters · 2 axioms · 0 invented entities

The central claims rest on standard Hawking radiation and the viability of asteroid-mass PBHs as all dark matter; no free parameters or invented entities are stated in the abstract.

axioms (2)
  • standard math Hawking radiation formulas for black-hole evaporation
    Used to determine photon emission spectra and peak frequencies for the quoted mass range.
  • domain assumption Extended PBH mass distributions can comprise all dark matter
    Invoked to compute local transit rates and explosion frequencies that underpin the detection-distance claims.

pith-pipeline@v0.9.1-grok · 5908 in / 1577 out tokens · 41473 ms · 2026-06-29T21:14:03.973097+00:00 · methodology

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