Quote:
Originally Posted by bojan
If it is metric, how all this tally with observed time dilation on distant objects (for example, very far away Supernovae.. their observed light curves are slower)?
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You have two frames of reference. In the Universe frame of reference, objects (not gravitationally bound) are at fixed points while space-time undergoes metric expansion.
Then there is the observers frame of reference. A distant galaxy moving under metric expansion will appear to move way from the observer.
An observer will be able to measure time dilation of a supernova light curve, which like the recession velocity of a distant galaxy is a function of cosmological redshift. This the key point to metric expansion.
For objects moving away in space which are not too distant, time dilation is a function of the velocity of the object and independent of cosmological redshift.
Regards
Steven