On the finiteness of light rays between a source and an observer on conformally stationary space-times

Authors
Giannoni, F Masiello, A Piccione, P
Citation
F. Giannoni et al., On the finiteness of light rays between a source and an observer on conformally stationary space-times, GEN RELAT G, 33(3), 2001, pp. 491-514
Citations number
18
Categorie Soggetti
Physics
Journal title
GENERAL RELATIVITY AND GRAVITATION
ISSN journal
00017701 → ACNP
Volume
33
Issue
3
Year of publication
2001
Pages
491 - 514
Database
ISI
SICI code
0001-7701(200103)33:3<491:OTFOLR>2.0.ZU;2-5
Abstract
We use a convexity condition to prove the finiteness of the number of light rays joining a pointlike source with a pointlike observer in a stationary relativistic spacetime. The result is extended to the case of conformally s tationary metrics under suitable boundedness assumptions on the conformal f actor. We discuss our hypotheses in some explicit examples of standard stat ic and stationary Lorentzian manifolds.