The Hubble's Law v=H(adsbygoogle = window.adsbygoogle || []).push({}); _{0}D

LHS of The Friedmann equation H^{2}/H_{0}^{2}

I am a bit confused with the following:

1: The Hubble constant H_{0}is the current universe velocity/distance ratio, it is basically a constant, so galaxies in the universe with a further distance, move away from each other at a faster speed? so the universe is accelerating expending? is this statement correct?

2: Does the Hubble constant H_{0}represent the current velocity/distance ratio? if it is, then the meaning of Friedmann equation is to compare a different expanding rate H (for past or further or any other imaging situations) to our current H_{0}, is this correct?

3:Rotation curve suggests that the circular velocity of galaxies are the same for any large value of distance r, doesn't that mean velocity/distance H_{0}is not constant?

Thanks

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# Questions on Hubble's law and Friedmann equation

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