My exact result is H_o^2/(4*pi*G) so density which you call "critical" (meaning what?), is 3/2 of mine. So why the density of the universe can't be just 1.5 of "critical" density? What would it mean for the universe?

The problem is that I don't have any free parameters to play with so if density is not 1.5 of "critical" then the theory that I'm testing can't be true.