Friday, December 16, 2011

distances

when defining cosmological distances, on has a choice of 4 definitions: proper, comoving, angular diameter and luminosity distance. normally, distances out to a redshift z appear in this order: angular diameter distance $<$ proper distance $<$ comoving distance $<$ luminosity distance. can you think of a cosmological model, where the order is inversed?

1 comment:

1. you'd need a contracting universe.