Emergence of a Renormalized $1/N$ Expansion in Quenched Critical Many-Body Systems

Benjamin Geiger, Juan Diego Urbina, Klaus Richter

We consider the fate of $1/N$ expansions in unstable many-body quantum systems, as realized by a quench across criticality, and show the emergence of ${\mathrm{e}}^{2\lambda t}/N$ as a renorma…