There seems to be a case for halving the Hubble constant .....(as defined by (a dot)/a), where a is the scale factor of the universe.....and redefining Hubbles law as v=2Hd.

The matter density then appears as 0.25 as it is rho/(rho critical) and rho critical is 3H^2/(8*pi*G).

So the matter density, although really 1.0 appears as 0.25, i.e. dark energy would be an illusion.

John Hunter.

http://vixra.org/abs/1003.0222