Ht. Cho et R. Kantowski, MEASURE ON A SUBSPACE OF FRW SOLUTIONS AND THE FLATNESS PROBLEM OF STANDARD COSMOLOGY, Physical review. D. Particles and fields, 50(10), 1994, pp. 6144-6149
We use the metric on the space of gravity fields given by DeWitt to co
nstruct a unique kinematic measure on the space of FRW simple fluids a
nd show that when the mass parameter Omega is used as a coordinate thi
s measure is singular at Omega = 1. This singularity, combined with th
e time evolution of Omega, distorts distributions of Omega values to b
e concentrated in the neighborhood of 1 at early times. It is a distor
ted distribution of Omega values that sometimes misleads the casual ob
server to conclude that Omega must be exactly equal to 1.