2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/36587The WDW equation of arbitrary Hartle-Hawking factor ordering for several minisuperspace universe models, such as the pure gravity FRW and Taub ones, is mapped onto the dynamics of corresponding classical oscillators. The latter ones are studied by the classical Ermakov invariant method, which is a natural aproach in this context. For the more realistic case of a minimally coupled massive scalar field, one can study, within the same type of approach, the corresponding squeezing features as a possible means of describing cosmological evolution. Finally, we comment on the analogy with the accelerator physics4 LaTex pages, ICSSUR 6 talk by H.C. Rosu, to be published in the NASA/CP series, some mathematical misprints correctedGeneral Relativity and Quantum CosmologyQuantum PhysicsErmakov approach for minisuperspace oscillatorstext