Eur. Phys. J. Plus (2011) 126: 28
https://doi.org/10.1140/epjp/i2011-11028-6

Regular Article

FRW universe models in conformally flat-spacetime coordinates I: General formalism

Department of Engineering, Oslo University College, St.Olavs Plass, 4, N-0130, Oslo, Norway

^* e-mail: steinar.johannesen@iu.hio.no

Received: 28 September 2010
Accepted: 9 November 2010
Published online: 23 March 2011

Abstract

The 3 -space of a universe model is defined at a certain simultaneity. Hence space depends on which time is used. We find a general formula generating all known and also some new transformations to conformally flat-spacetime coordinates. A general formula for the recession velocity is deduced.