{"work":{"id":"c16d7a50-5dd2-4f8e-995b-4328f56bdb48","openalex_id":null,"doi":null,"arxiv_id":"1812.07114","raw_key":null,"title":"Black-bounce to traversable wormhole","authors":null,"authors_text":"A","year":2018,"venue":"gr-qc","abstract":"So-called \"regular black holes\" are a topic currently of considerable interest in the general relativity and astrophysics communities. Herein we investigate a particularly interesting regular black hole spacetime described by the line element \\[ ds^{2}=-\\left(1-\\frac{2m}{\\sqrt{r^{2}+a^{2}}}\\right)dt^{2}+\\frac{dr^{2}}{1-\\frac{2m}{\\sqrt{r^{2}+a^{2}}}} +\\left(r^{2}+a^{2}\\right)\\left(d\\theta^{2}+\\sin^{2}\\theta \\;d\\phi^{2}\\right). \\] This spacetime neatly interpolates between the standard Schwarzschild black hole and the Morris-Thorne traversable wormhole; at intermediate stages passing through a black-bounce (into a future incarnation of the universe), an extremal null-bounce (into a future incarnation of the universe), and a traversable wormhole. As long as the parameter $a$ is non-zero the geometry is everywhere regular, so one has a somewhat unusual form of \"regular black hole\", where the \"origin\" $r=0$ can be either spacelike, null, or timelike. Thus this spacetime generalizes and broadens the class of \"regular black holes\" beyond those usually considered.","external_url":"https://arxiv.org/abs/1812.07114","cited_by_count":null,"metadata_source":"pith","metadata_fetched_at":"2026-07-10T11:07:02.060295+00:00","pith_arxiv_id":"1812.07114","created_at":"2026-05-10T08:32:51.764495+00:00","updated_at":"2026-07-10T11:07:02.060295+00:00","title_quality_ok":true,"display_title":"Black-bounce to traversable wormhole","render_title":"Black-bounce to traversable wormhole"},"hub":{"state":{"work_id":"c16d7a50-5dd2-4f8e-995b-4328f56bdb48","tier":"hub","tier_reason":"10+ Pith inbound or 1,000+ external citations","pith_inbound_count":29,"external_cited_by_count":null,"distinct_field_count":3,"first_pith_cited_at":"2025-08-14T22:21:14+00:00","last_pith_cited_at":"2026-07-09T08:24:20+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":"2026-08-21T20:39:40.309449+00:00","tier_text":"hub"},"tier":"hub","role_counts":[{"context_role":"background","n":5}],"polarity_counts":[{"context_polarity":"background","n":3},{"context_polarity":"unclear","n":2}],"runs":{},"summary":{},"graph":{},"authors":[]}}