{"paper":{"title":"Maximum Energy of Particles Accelerated in Gamma-Ray Burst Afterglow Shocks","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"Short GRB afterglows develop a GeV synchrotron cutoff from PIC-limited electron acceleration within hours of the trigger.","cross_cats":["physics.plasm-ph"],"primary_cat":"astro-ph.HE","authors_text":"Daniel Gro\\v{s}elj, Dimitrios Giannios, Lorenzo Sironi, Paz Beniamini, Sof\\'ia Guevara-Montoya, Zhao-Feng Wu","submitted_at":"2026-01-27T03:08:40Z","abstract_excerpt":"Particle acceleration in relativistic collisionless shocks remains an open problem in high-energy astrophysics. Particle-in-cell (PIC) simulations predict that electron acceleration in weakly magnetized shocks proceeds via small-angle scattering, leading to a maximum electron energy significantly below the Bohm limit. This upper bound on electron energy manifests observationally as a characteristic synchrotron cutoff, providing a direct probe of the underlying acceleration physics. Gamma-ray burst (GRB) afterglows offer an exceptional laboratory for testing these predictions. Here, we model th"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"low-energy bursts in low-density environments, typical of short GRBs, exhibit a pronounced synchrotron cutoff in the GeV band within minutes to hours after the trigger","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"That PIC simulation results for weakly magnetized shocks apply directly and without modification to the conditions in GRB afterglow shocks","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"PIC-motivated acceleration in GRB afterglows produces an observable GeV synchrotron cutoff in low-density short bursts that future observations can use to distinguish from the Bohm limit.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Short GRB afterglows develop a GeV synchrotron cutoff from PIC-limited electron acceleration within hours of the trigger.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"69eced2a334458050eea695d083dab58316c70f2d20cbc1ec49d9d05eec5e7be"},"source":{"id":"2601.19135","kind":"arxiv","version":3},"verdict":{"id":"f587cc8d-b12a-4ac1-a4ff-0a371640db3b","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-16T11:20:37.936438Z","strongest_claim":"low-energy bursts in low-density environments, typical of short GRBs, exhibit a pronounced synchrotron cutoff in the GeV band within minutes to hours after the trigger","one_line_summary":"PIC-motivated acceleration in GRB afterglows produces an observable GeV synchrotron cutoff in low-density short bursts that future observations can use to distinguish from the Bohm limit.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"That PIC simulation results for weakly magnetized shocks apply directly and without modification to the conditions in GRB afterglow shocks","pith_extraction_headline":"Short GRB afterglows develop a GeV synchrotron cutoff from PIC-limited electron acceleration within hours of the trigger."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2601.19135/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":2,"snapshot_sha256":"cecca40e8290f0523c63f84c3ed0204a8151e425c6ab7828b7b59f5d23fba1bc"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}