00940nam0-22003131i-450-9900014429104033213-540-66898-5000144291FED01000144291(Aleph)000144291FED0100014429120000920d2000----km-y0itay50------baengRay Optics, Fermat's Principle, and Applications to General RelativityVolker PerlickBerlin [etc.]Springerc2000X, 220 p.23 cmLecture Notes in Physics. N.s. M, Monographs61RelativitàGravità530.11Perlick,Volker62532ITUNINARICAUNIMARCBK99000144291040332123-271D.S.F. 6491FI1FI1Ray Optics, Fermat's Principle, and Applications to General Relativity374579UNINAING01