1998/02/21 by V. R. Krym
Physics and Astronomy · #gr-qc
published as Theor.Math.Phys. 119 (1999) 605-617; Teor.Mat.Fiz. 119 (1999) 264-281 · 20 pages, PostScript
arxiv created 1998/02/21 · arxiv updated 2009/11/30
We give a short historical review of early Kaluza-Klein theories. We study various causal structures on manifolds, especially those which cannot be described by a metric tensor with signature (+---). The smooth structure (atlas) on a manifold is found to be related with its causal structure.