Irrespective of local conditions imposed on the metric, any extendible spacetime U has a maximal extension containing no closed causal curves outside the chronological past of U. We prove this fact and interpret it as impossibility (in classical general relativity) of the time machines insofar as the latter are defined to be causality-violating regions created by human beings (as opposed to those appearing spontaneously).
Classical and Quantum Gravity
- Pub Date:
- August 2002
- General Relativity and Quantum Cosmology;
- Mathematics - Differential Geometry
- A corrigendum (to be published in CQG) has been added to correct an important mistake in the definition of locality