Analytical relationships between source-receiver distances, redshifts and luminosity distances under pure modes of expansion

International audienceThe relationships between the redshifts, the luminosity distance and the true distances at the times of light emission and reception, are formally calculated in Euclidean spaces whose expansion is describable using simple functions: proportional to cosmic time, power law or exponential, and for the different assumptions about the origin of the redshift: kinematic, relativistic and wave stretching effects. None of these combinations gives the same results in terms of redshift, of horizon, of distances and of deviation from the Hubble law. This systematic analysis provides the limit cases of expansion scenarios