2000/04/27 by Yi-Ping Qin, Qin, Yi-Ping
Earth and Planetary Sciences · Environmental Science · Physics and Astronomy · #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #Geological Formations and Processes Exploration #Geological Modeling and Analysis #Methane Hydrates and Related Phenomena #gr-qc
paper · pdf · doi:10.48550/arxiv.gr-qc/0004080
5 pages
arxiv created 2000/04/27 · openalex publication_date 2000/04/27 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
By extending the exterior Schwarzschild spacetime in two opposite directions with the Kruskal method, we get an extension which has the same T-X spacetime diagram as has the conventional Kruskal extension, while allowing its regions I and IV to correspond to different directions of the original spacetime. We further extend the exterior Schwarzschild spacetime in all directions and get a 4-dimensional form of the Kruskal extension. The new form of extension includes the conventional one as a part of itself. From the point of view of the 4-dimensional form, region IV of the conventional extension does not belong to another universe but is a portion of the same exterior Schwarzschild spacetime that contains region I. The two regions are causally related: particles can move from one to the other.