{"work":{"id":"3cfd4fc2-cd1a-4c82-956b-7492cb4e3f3b","openalex_id":null,"doi":null,"arxiv_id":"1806.06840","raw_key":null,"title":"A semiclassical ramp in SYK and in gravity","authors":null,"authors_text":"Phil Saad, Stephen H","year":2018,"venue":"hep-th","abstract":"In finite entropy systems, real-time partition functions do not decay to zero at late time. Instead, assuming random matrix universality, suitable averages exhibit a growing \"ramp\" and \"plateau\" structure. Deriving this non-decaying behavior in a large $N$ collective field description is a challenge related to one version of the black hole information problem. We describe a candidate semiclassical explanation of the ramp for the SYK model and for black holes. In SYK, this is a two-replica nonperturbative saddle point for the large $N$ collective fields, with zero action and a compact zero mode that leads to a linearly growing ramp. In the black hole context, the solution is a two-sided black hole that is periodically identified under a Killing time translation. We discuss but do not resolve some puzzles that arise.","external_url":"https://arxiv.org/abs/1806.06840","cited_by_count":null,"metadata_source":"pith","metadata_fetched_at":"2026-05-25T05:56:39.985258+00:00","pith_arxiv_id":"1806.06840","created_at":"2026-05-11T17:41:05.934304+00:00","updated_at":"2026-05-25T05:56:39.985258+00:00","title_quality_ok":false,"display_title":"A semiclassical ramp in SYK and in gravity","render_title":"A semiclassical ramp in SYK and in gravity"},"hub":{"state":{"work_id":"3cfd4fc2-cd1a-4c82-956b-7492cb4e3f3b","tier":"hub","tier_reason":"10+ Pith inbound or 1,000+ external citations","pith_inbound_count":20,"external_cited_by_count":null,"distinct_field_count":3,"first_pith_cited_at":"2019-05-20T18:00:01+00:00","last_pith_cited_at":"2026-05-21T18:00:28+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":"2026-05-28T03:28:07.587187+00:00","tier_text":"hub"},"tier":"hub","role_counts":[{"context_role":"background","n":6}],"polarity_counts":[{"context_polarity":"background","n":4},{"context_polarity":"support","n":1},{"context_polarity":"unclear","n":1}],"runs":{},"summary":{},"graph":{},"authors":[]}}