{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"251265035d0b59ff7a724b06b8f8f630908c36cd4e82328155e3f258a2a2d6d4","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b","d31eedfd30635ee84957b4f61ffe7c56ea3e5b12510f32c5e0b0769e85884abd"],"salt":"2f06023d9e85cb81c545683a4b58364a31ed456a3aad68133efc8d5cbe3aad8c","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"qft.string-vacua.6d-string-universality","kind":"well-posed","literature_status":"partially-resolved","n":"2","parents":[],"plain":"Six-dimensional supergravity theories (gravity plus a symmetry between bosons and fermions) can be listed by checking quantum consistency conditions called anomaly cancellation. Whether every theory that passes these checks actually comes from string theory is unknown.","posed_since":"2009","precise":"For 6D $N=(1,0)$ supergravity with $T$ tensor multiplets, gauge group $G$ and hypermultiplet content $H$, Green-Schwarz anomaly cancellation restricts $(T, G, H)$. Determine whether every anomaly-free model that meets all known consistency conditions is realized by a string compactification (string universality, Kumar and Taylor 2009), or identify the additional conditions that remove the remainder.","problem_ref":"d31eedfd30635ee84957b4f61ffe7c56ea3e5b12510f32c5e0b0769e85884abd","references":"","settled_by":"A proof that consistency conditions (anomalies, brane-probe unitarity, black-hole arguments) reduce the anomaly-free list exactly to F-theory and heterotic models, or an anomaly-free model shown consistent with no string realization.","status_note":"In ten dimensions the unrealized anomaly-free theories were excluded (Adams, DeWolfe, Taylor 2010); in 6D brane-probe unitarity removed some anomaly-free models (Kim, Shiu, Vafa 2019), and anomaly-free models without known string realization remain.","title":"Is every anomaly-free six-dimensional supergravity realized in string theory?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"7f8c01884e34b065535f46404d50cee04ee5c96f023c4a0e92e930ff00c708ee","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"3953fbed7866ba9e7a835078e7820f900f0442ff57a090d662131e33f931421b","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"DgprdnY-w2YgTgRyrrNi94tQmMmBdjnlgUvnzl7n91ARkbVgIxL9VpjdNhyZMCt7a0pv1GXPzHsEglFK9KPjDA"},"schema":"pubphys.envelope/1"},"record_hash":"7f8c01884e34b065535f46404d50cee04ee5c96f023c4a0e92e930ff00c708ee","leaf_index":3682}