Isocausal spacetimes may have different causal boundaries
Abstract
We construct an example which shows that two isocausal spacetimes, in the sense introduced recently in GarcíaParrado and Senovilla (2003 Class. Quantum Grav. 20 62564), may have cboundaries which are not equal (more precisely, not equivalent, as no bijection between the completions can preserve all the binary relations induced by causality). This example also suggests that isocausality can be useful for the understanding and computation of the cboundary.
 Publication:

Classical and Quantum Gravity
 Pub Date:
 September 2011
 DOI:
 10.1088/02649381/28/17/175016
 arXiv:
 arXiv:1103.2083
 Bibcode:
 2011CQGra..28q5016F
 Keywords:

 Mathematical Physics;
 General Relativity and Quantum Cosmology;
 Mathematics  Differential Geometry;
 83C75;
 53C50;
 83C20
 EPrint:
 Minor modifications, including the title, which matches now with the published version. 12 pages, 3 figures