{"paper":{"title":"Self-induced polar order of active Brownian particles in a harmonic trap","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["physics.bio-ph","physics.flu-dyn"],"primary_cat":"cond-mat.soft","authors_text":"Holger Stark, Katrin Wolff, Marc Hennes","submitted_at":"2014-02-06T16:32:30Z","abstract_excerpt":"Hydrodynamically interacting active particles in an external harmonic potential form a self-assembled fluid pump at large enough P\\'eclet numbers. Here, we give a quantitative criterion for the formation of the pump and show that particle orientations align in the self-induced flow field in surprising analogy to ferromagnetic order where the active P\\'eclet number plays the role of inverse temperature. The particle orientations follow a Boltzmann distribution $\\Phi(\\mathbf{p}) \\sim \\exp(A p_z)$ where the ordering mean field $A$ scales with active P\\'eclet number and polar order parameter. The "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1402.1397","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"}