Exploring Cosmic Rays from Gravity-Limited Acceleration at Supermassive Black Holes

We show that horizon-scale magnetic fields around supermassive black holes (SMBHs), only limited by gravity, yield a universal, model-independent ceiling on electromagnetic energy density.

By Manao, Resconi, Rieger +2Oct 16, 2026

Score████░░░░░░4.2

VerdictWorth a reader's time today.

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Abstract

We show that horizon-scale magnetic fields around supermassive black holes (SMBHs), only limited by gravity, yield a universal, model-independent ceiling on electromagnetic energy density. For rotating SMBHs, this field enables particle acceleration up to ~ 10²⁷\,eV set solely by fundamental constants. We identify a parameter space in accretion rate and magnetic field strength in which quiescent nuclei simultaneously satisfy the transparency conditions for Ultra-High-Energy Cosmic Rays (UHECR) escape and the field requirements for reaching Ultra-High Energies (UHE), naturally complementing photon-rich Active Galactic Nuclei (AGN), which favor neutrino production but suppress UHECR escape. We observe that, when including curvature energy losses, the energy of the primaries scales weakly as E_curv propto M¹/4 and allows to achieve UHE across different compositions and SMBHs masses (10⁶--10¹⁰ M_odot), without requiring extreme spins or super-Eddington accretion. A cross-correlation of the Pierre Auger Observatory (PAO) public data with galaxies hosting reliably measured SMBH masses, separating AGN from quiescent hosts, reveals marginal local excesses (lesssim 2.8σ) consistent with isotropy after correcting for the look-elsewhere effect. The framework provides a direct link between black-hole physics and the maximum energies of cosmic particles, and defines concrete observational tests for next-generation UHECR datasets.

Elena Manao, Elisa Resconi, Frank M. Rieger, Paolo Padovani, Gia Dvali

The editor's rubric

Heuristic review

Leverage3 / 5: A method or resource many groups across the field will adopt within a year.; 18% of this desk’s rubric
Magnitude2 / 5: Solid incremental gain on a meaningful problem.; 20% of this desk’s rubric
Evidence3 / 5: Solid: multiple benchmarks or cohorts, ablations, fair baselines, released code or data.; 22% of this desk’s rubric
Novelty3 / 5: A genuinely new approach to an open problem.; 22% of this desk’s rubric
Trajectory3 / 5: A clear path to scale.; 10% of this desk’s rubric
Stakes2 / 5: Benefits a professional community (practitioners, clinicians, engineers).; 8% of this desk’s rubric

Dimension	Level	Weight	What that level means
Leverage	███░░ 3	18%	A method or resource many groups across the field will adopt within a year.
Magnitude	██░░░ 2	20%	Solid incremental gain on a meaningful problem.
Evidence	███░░ 3	22%	Solid: multiple benchmarks or cohorts, ablations, fair baselines, released code or data.
Novelty	███░░ 3	22%	A genuinely new approach to an open problem.
Trajectory	███░░ 3	10%	A clear path to scale.
Stakes	██░░░ 2	8%	Benefits a professional community (practitioners, clinicians, engineers).

Editor’s rationale

Heuristic triage from title and abstract text only, not a reading of the paper. Cues found: method (we report); breadth (general-purpose); novelty (alternative to status quo, discovery); verification (independent replication); scale (scalable); stakes (energy).

How the score was computed

rank-2026-10-18

Score████░░░░░░4.2

Score = 10 × (75% × adjusted merit / 10 + 15% × attention + 10% × freshness)

Desks place stronger verdicts first, then use this score to order work within the same verdict.

Merit: 5.4 / 10; Weighted rubric, evidence-gated.
Adjusted merit: 4.6 / 10; Shrunk toward the desk prior by editor confidence (44%).
Attention: 0%; Citations, upvotes, points, mentions.
Freshness: 76%; Half-life decay since publication.

Citations0 (reference 20, via openalex, Oct 19, 2026, 07:29 UTC)

The record

Reviewed by heuristic-v7 on Oct 19, 2026, 07:29 UTC. Paper type: method.
Categories: astro-ph.HE, astro-ph.GA
TOP, No.5 in the Physics edition of October 19, 2026.