I am trying to get my head around the concept of redshifts and their relation to powers. Consider the observe $O$ at rest (who is measuring the power) and emitter $E$ in one of the three following situations:
Moving in Minkowski space at a velocity $\vec{v}$.
At rest (relative to $O$) in a non-Minkowski space (i.e. a non-expanding universe with a gravitational field.)
- At a fixed co-moving coordinate (relative to $0$) in a expanding flat universe.
And let us call the redshift associated with each $z_D$, $z_G$ and $z_C$. I know that in the case of cosmological redshift the flux goes like: $$\frac{1}{(1+z_C)^2}$$ since both the energy of the photons has change and the number which have arrive per unit time. My question is how does the power change in the first two cases? and how does this relate to the type of redshift?