{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"ae412eb46992e9644983cd31777d4a93feddf163df6784062f018bc2488abd89","created":"2026-10-03T07:18:09Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011","db36ffbc79f4164eb5fca1b1571721847649278015dd6cb1de0d84d0aec56c30"],"salt":"187bf0ccf20e1a1a140f51f132bc12c8bb0223d8d65ad40a66f48dbda8226372","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"identification","assisted_by":[],"external_id":"qft.non-ads-holography.ds-entropy-count","kind":"well-posed","literature_status":"open","n":"1","parents":[{"note":"","parent_revision":"db36ffbc79f4164eb5fca1b1571721847649278015dd6cb1de0d84d0aec56c30","relation":"special_case"}],"plain":"The horizon of an expanding universe has an entropy proportional to its area, just like a black hole. Which quantum states it counts is unknown.","posed_since":"1977","precise":"The Gibbons-Hawking entropy of a d-dimensional de Sitter horizon is $S = A c^3/(4 G \\hbar)$ with $k_B = 1$. Find a statistical system whose state count reproduces S including the one-loop logarithmic correction computed by Anninos, Denef, Law and Sun (2020).","problem_ref":null,"references":"","settled_by":"A microscopic system with a derived match of the leading area term and the logarithmic correction.","status_note":"The static-patch algebra of observables was shown to be of von Neumann type $\\mathrm{II}_{1}$ with a maximum-entropy state (Chandrasekaran, Longo, Penington, Witten 2022), without a microscopic count.","title":"Microscopic count of de Sitter horizon entropy","topic_ref":"4447f2d48104cd4793e366a0c17a947b19173f616f89b118e14ec361109b57ad"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"97d827659d3d54657f570adf7518309235c3fcebc0bf86bf2e13c8ee876a635b","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"fe45591aa0bbc5fa562bb73182df2774bea393198b8bdf586c8e2e79f82a464f","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"pQiC_6NekVXkFtAMZ8iaHt4zSRT_oMCpBSCNKydOna9Fn0Bt9jo7dWrOMZ74BMZxh_Nintdsyy0X9O-ZXCjZCA"},"schema":"pubphys.envelope/1"},"record_hash":"97d827659d3d54657f570adf7518309235c3fcebc0bf86bf2e13c8ee876a635b","leaf_index":1929}