2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/41297We analyze the onset of classical field configurations after a phase transition. Firstly, we motivate the problem by means of a toy model in quantum mechanics. Subsequently, we consider a scalar field theory in which the system-field interacts with its environment, represented both by further scalar fields and by its own short-wavelength modes. We show that, for very rapid quenches, the order parameter can be treated classically by the time that it has achieved its ground state values (spinodal time).12 pages, 8 figures, to be published in the Proceedings of the Peyresq VI, Cosmological inflation and primordial fluctuations. Energy desert and submillimeter gravity, Peyresq, June 2001High Energy Physics - PhenomenologyCondensed MatterQuantum Physicstext