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 Verdict Feb23-12 03:02 PM

Redshift Parameter

1. The problem statement, all variables and given/known data
The cosmological principle can also be used to derive an expression for the redshift of light
(from far away galaxies) in terms of the scale factors at emission and observation. Use the fact
that the wavelength in terms of the co-moving coordinates Δx is independent of time to derive an expression for http://upload.wikimedia.org/wikipedi...01aea4749d.png in terms of the scale factors a(tobs) and a(tem). The redshift parameter z is the typical parameter used to indicate distance in cosmology.

(I suppose it is obvious, but obs stands for observer and em for emitter)

2. Relevant equations