{"paper":{"title":"Comment on \"Symplectic integration of magnetic systems\": a proof that the Boris algorithm is not variational","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math.NA"],"primary_cat":"physics.comp-ph","authors_text":"C. L. Ellison, H. Qin, J. W. Burby","submitted_at":"2015-09-09T17:35:18Z","abstract_excerpt":"The Boris algorithm for integrating charged particle trajectories in electric and magnetic fields is popular due to its simple implementation, rapid iteration, and observed long-term numerical fidelity. The underlying cause of this long-term fidelity has become a matter of controversy, with one article claiming the method to be symplectic [S. D. Webb, J. Comput. Phys. 270 (2014) 570], and others claiming the method to be volume preserving but not symplectic [e.g. H. Qin et al., Phys. Plasmas 20 (2013) 084503]. To resolve the discrepancy, this letter leverages a discrete Helmholtz condition to "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1509.02863","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}