2007/03/31 by E. Minguzzi · 3 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Noncommutative and Quantum Gravity Theories #gr-qc
paper · pdf · doi:10.1088/0264-9381/25/1/015010
published as Class.Quant.Grav.25:015010,2008 · 27 pages, 2 figures, uses Latex package "psfrag". v3: Old title: ``On the relationship between stable causality and K-causality''. v4: fixed a small problem with lemma 5.5
arxiv created 2007/11/29 · openalex publication_date 2007/12/11 · arxiv updated 2009/12/01 · openalex created_date 2020/04/10 · openalex updated_date 2026/07/30
Hawking's stable causality implies Sorkin and Woolgar's K -causality. The work investigates the possible equivalence between the two causality requirements, an issue which was first considered by H Seifert and then raised again by R Low after the introduction of K -causality. First, a new proof is given that a spacetime is stably causal iff the Seifert causal relation is a partial order. It is then shown that given a K -causal spacetime and having chosen an event, the light cones can be widened in a neighborhood of the event without spoiling K -causality. The idea is that this widening of the light cones can be continued leading to a global one. Unfortunately, due to some difficulties in the inductive process the author was not able to complete the program for a proof as originally conceived by H Seifert. Nevertheless, it is proved that if K -causality coincides with stable causality then in any K -causal spacetime the K + future coincides with the Seifert future. Explicit examples are provided which show that the K + future may differ from the Seifert future in causal spacetimes.