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Let us assume that Hubble's Constant H is really constant. Therefore:

a' / a = H

where a is the scale factor.

The solution to this equation is:

a(t) = exp(H t)

This equation describes an accelerating universe with deceleration parameter q given by:

q = - a'' a / a'^2 = -1

This value of q is in agreement with current observations.

By the way, a constant value of H implies the Hubble radius which is a measure of the size of the observable Universe, R = c / H, is constant. If the above equation is true then in some sense the Universe is now static.

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# Constant Hubble parameter -> accelerating Universe?

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