Is the universe expanding?
Abstract
It is shown that spherically symmetric static general relativistic cosmological spacetimes can reproduce the same cosmological observations as the currently favored FriedmannRobertsonWalker universes, if the usual assumptions are made about the local physical laws determining the behavior of matter, provided that the universe is inhomogeneous and our galaxy is situated close to one of its centers. Only (i) unverifiable a priori assumptions, (ii) detailed physical and astrophysical arguments, or (iii) observation of the time variation of cosmological quantities can lead us to conclude that the universe we live in is not such a static spacetime.
 Publication:

General Relativity and Gravitation
 Pub Date:
 February 1978
 DOI:
 10.1007/BF00760145
 Bibcode:
 1978GReGr...9...87E
 Keywords:

 Cosmology;
 Relativity;
 Singularity (Mathematics);
 Background Radiation;
 Big Bang Cosmology;
 Equations Of State;
 Neutrinos;
 Pressure Effects;
 Radiation Distribution;
 SpaceTime Functions;
 Astrophysics;
 Expansion:Universe