Late-time evolution of cosmological models with fluids obeying a Shan-Chen-like equation of state

摘要

Classical as well as quantum features of the late-time evolution ofcosmological models with fluids obeying a Shan-Chen-like equation of state arestudied. The latter is of the type $p=w_{\rm eff}(\rho)\,\rho$, and has beenused in previous works to describe, e.g., a possible scenario for the growth ofthe dark-energy content of the present Universe. At the classical level thefluid dynamics in a spatially flat Friedmann-Robertson-Walker backgroundimplies the existence of two possible equilibrium solutions depending on themodel parameters, associated with (asymptotic) finite pressure and energydensity. We show that no future cosmological singularity is developed duringthe evolution for this specific model. The corresponding quantum effects in thelate-time behavior of the system are also investigated within the framework ofquantum geometrodynamics, i.e., by solving the (minisuperspace) Wheeler-DeWittequation in the Born-Oppenheimer approximation, constructing wave-packets andanalyzing their behavior.