Duality Invariance and Cosmological Dynamics

摘要: A duality transformation that interrelates expanding and contracting cosmological models is shown to single out a invariant, interacting two-component description of any irrotational, geodesic shear-free cosmic medium with vanishing three-curvature scalar. We have applied this feature system matter radiation, mixture dark energy, minimal conformal scalar fields, an enlarged Chaplygin gas model the substratum. extended concept transformations perturbations demonstrated invariance adiabatic pressure under these transformations.