define a universality class in terms of the density of states of their quasilocalized low-
frequency modes. Explicitly, once the hybridization with standard Debye (extended) modes
is avoided, a number of such models exhibit a universal density of states, depending on the
mode frequencies as D (ω)∼ ω 4. It is unknown, however, how wide this universality class
is, and whether it also pertains to more realistic models of glass formers. To address this …