{"work":{"id":"b4cf8745-b122-490d-8075-44981e0f6fe9","openalex_id":null,"doi":null,"arxiv_id":"gr-qc/9305007","raw_key":null,"title":"Average Entropy of a Subsystem","authors":null,"authors_text":"Don N","year":1993,"venue":"gr-qc","abstract":"If a quantum system of Hilbert space dimension $mn$ is in a random pure state, the average entropy of a subsystem of dimension $m\\leq n$ is conjectured to be $S_{m,n}=\\sum_{k=n+1}^{mn}\\frac{1}{k}-\\frac{m-1}{2n}$ and is shown to be $\\simeq \\ln m - \\frac{m}{2n}$ for $1\\ll m\\leq n$. Thus there is less than one-half unit of information, on average, in the smaller subsystem of a total system in a random pure state.","external_url":"https://arxiv.org/abs/gr-qc/9305007","cited_by_count":null,"metadata_source":"pith","metadata_fetched_at":"2026-05-23T18:08:18.097884+00:00","pith_arxiv_id":"gr-qc/9305007","created_at":"2026-05-09T06:55:39.338346+00:00","updated_at":"2026-06-05T21:23:00.469572+00:00","title_quality_ok":false,"display_title":"Average Entropy of a Subsystem","render_title":"Average Entropy of a Subsystem"},"hub":{"state":{"work_id":"b4cf8745-b122-490d-8075-44981e0f6fe9","tier":"hub","tier_reason":"10+ Pith inbound or 1,000+ external citations","pith_inbound_count":13,"external_cited_by_count":null,"distinct_field_count":5,"first_pith_cited_at":"2019-05-21T17:27:30+00:00","last_pith_cited_at":"2026-05-15T20:41:21+00:00","author_build_status":"not_needed","summary_status":"needed","contexts_status":"needed","graph_status":"needed","ask_index_status":"not_needed","reader_status":"not_needed","recognition_status":"not_needed","updated_at":"2026-06-19T20:17:57.836636+00:00","tier_text":"hub"},"tier":"hub","role_counts":[{"context_role":"background","n":7}],"polarity_counts":[{"context_polarity":"background","n":7}],"runs":{},"summary":{},"graph":{},"authors":[]}}