2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/231184Nonthermal fixed points represent basic properties of quantum field theories, in addition to vacuum or thermal equilibrium fixed points. The functional renormalization group on a closed real-time path provides a common framework for their description. For the example of an O(N) symmetric scalar theory it reveals a hierarchy of fixed point solutions, with increasing complexity from vacuum and thermal equilibrium to nonequilibrium.32 pages, Nucl. Phys. B version (minor changes of wordings)High Energy Physics - TheoryOther Condensed MatterHigh Energy Physics - PhenomenologyNuclear Theorytext