Impulsive Electromagnetic Emission near a Black Hole
Bibliographic record
Abstract
Abstract The electromagnetic signature of a point explosion near a Kerr black hole (BH) is evaluated. The first repetitions produced by gravitational lensing are not periodic in time; periodicity emerges only as the result of multiple circuits of the prograde and retrograde light rings and is accompanied by exponential dimming. Gravitational focusing creates a sequence of concentrated caustic features and biases the detection of a repeating source toward alignment of the BH spin with the plane of the sky. We consider the polarization pattern in the case of emission by the Lorentz upboosting and reflection of a magnetic field near the explosion site. Then the polarized fraction of the detected pulse approaches unity, and rays propagating near the equatorial plane maintain a consistent polarization direction. Near a slowly accreting supermassive BH (SMBH), additional repetitions are caused by reflection off annular fragments of an orbiting disk that has passed through an ionization instability. These results are applied to the repeating fast radio burst (FRB) source 121102, giving a concrete and predictive example of how FRB detectability may be biased by lensing. A gravitational lensing delay of 10–30 s, and reflection delay up to ∼104 s, are found for emission near the innermost stable circular orbit of a 3 × 105 M ⊙ SMBH; these effects combine to produce interesting correlations between delay time and burst fluence. A similar repetitive pulse envelope could be seen in the gravitational wave signal produced by a collision between compact stars near a SMBH.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".