{"paper":{"title":"A remark on the ultrapower algebra of the hyperfinite factor","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math.FA"],"primary_cat":"math.OA","authors_text":"Ionut Chifan, Sayan Das","submitted_at":"2018-02-19T13:49:49Z","abstract_excerpt":"On page 43 in \\cite{Po83} Sorin Popa asked whether the following property holds: \\emph{If $\\omega$ is a free ultrafilter on $\\mathbb N$ and $\\mathcal R_1\\subseteq \\mathcal R$ is an irreducible inclusion of hyperfinite II$_1$ factors such that $\\mathcal R'\\cap \\mathcal R^\\omega\\subseteq \\mathcal R^\\omega_1$ does it follows that $\\mathcal R_1=\\mathcal R$?} In this short note we provide an affirmative answer to this question."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1802.06628","kind":"arxiv","version":2},"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"}