{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"b16198eae862b521808a66d24e5c23a28a971e91cf4957020239f335dbb789d7","created":"2026-10-03T07:18:09Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"e3eca847bd21efd1e383df55e518e07ff1a399231023e385c21469554a454a99","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":"1","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":null,"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":"925c6562a6d5b6dc4a9070f6df384c4141e0b53a77a35c230ef4f29c1888453c"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"d31eedfd30635ee84957b4f61ffe7c56ea3e5b12510f32c5e0b0769e85884abd","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"0aa39e461af7eada50376ae35bd5b1925de6d48bfa0ec10f73b6418a772709c4","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"jVZiC_9tFFH1e4LPURQf_r6O7AXb25qKao_Lk4vaAkQtIiKssBqmq7Oxiis4wqa1eLbQdqcNeOJQVSMjVSTECA"},"schema":"pubphys.envelope/1"},"record_hash":"d31eedfd30635ee84957b4f61ffe7c56ea3e5b12510f32c5e0b0769e85884abd","leaf_index":1957}