2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/222645The accelerating Friedmann flat universe, filled with an ideal fluid with a linear (oscillating) inhomogeneous equation of state (EoS) depending on time, is reviewed. The equations of motions are solved. It is shown that in some cases there appears a quasi-periodic universe, which repeats the cycles of phantom-type space acceleration.Dedicated to the 70th anniversary of Professor Iver BrevikGeneral Relativity and Quantum Cosmologytext