The rules of calculating three undetermined functions which defined a solution in the LTB model are used to study the class of exact nonhomogeneous models with f (μ) = 1, Λ = 0. The parameter ν(μ) defined the difference between LTB and FRW models is found out and the limit transformation to the FRW model is shown. The initial conditions are present throught density and Habble function at the mo...

The minisuperspace dynamics of the Friedmann-Robertson-Walker (FRW) and of the Taub Universes in the context of a Generalized Uncertainty Principle is analyzed in detail. In particular, the motion of the wave packets is investigated and, in both the models, the classical singularity appear to be probabilistic suppressed. Moreover, the FRW wave packets approach the Planckian region in a stationa...

Analytic expressions for distance-redshift relations which have been corrected for the effects of some inhomogeneities in the Friedmann-Robertson-Walker (FRW) mass density are used to illustrate the significance of inhomogeneities on a determination of q 0 made by using Type Ia supernovae. The value of q 0 inferred from a given set of observations depends on the fractional amount of matter in i...

We extend the direct quantum approach of the standard FRW cosmology from 4D to 5D and obtain a Hamiltonian formulation for a wave-like 5D FRW cosmology. Using a late-time approximation we isolate out a y-part from the full wave function of the 5D Universe. Then we find that the compactness of the fifth dimension y yields a quantized spectrum for the momentum P5 along the fifth dimension, and we...

The idea that the universe has zero total energy when one includes the contribution from the gravitational field is reconsidered. A Hamiltonian is proposed as an energy for the exact equations of FRW cosmology: it is then shown that this energy is constant. Thus open and critically open FRW universes have the energy of their asymptotic state of infinite dilution, which is Minkowski space with z...