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## Main Question or Discussion Point

I am a bit confused here. Is cosmological redshift the same as doppler redshift?

This is from wikipedia:

"The redshift z often is described as a redshift velocity, which is the recessional velocity that would produce the same redshift if it were caused by a linear Doppler effect (which, however, is not the case, as the shift is caused in part by a cosmological expansion of space, and because the velocities involved are too large to use a non-relativistic formula for Doppler shift)"

If the cosmological redshift is based in the expansion of the metric, that means that the galaxies we observe at high z are not really receding at those superluminal speeds, right?

But the cosmological redshift is actually derived from the assumption that the redshift is doppler or recesional, at least in the fist years of modern cosmology, so it's a little confusing,can someone clear this up a little?

This is from wikipedia:

"The redshift z often is described as a redshift velocity, which is the recessional velocity that would produce the same redshift if it were caused by a linear Doppler effect (which, however, is not the case, as the shift is caused in part by a cosmological expansion of space, and because the velocities involved are too large to use a non-relativistic formula for Doppler shift)"

If the cosmological redshift is based in the expansion of the metric, that means that the galaxies we observe at high z are not really receding at those superluminal speeds, right?

But the cosmological redshift is actually derived from the assumption that the redshift is doppler or recesional, at least in the fist years of modern cosmology, so it's a little confusing,can someone clear this up a little?