Low-energy effective theory of nonthermal fixed points in a multicomponent Bose gas

Nonthermal fixed points in the evolution of a quantum many-body system quenched far out of equilibrium manifest themselves in a scaling evolution of correlations in space and time. We develop a low-energy effective theory of nonthermal fixed points in a bosonic quantum many-body system by integrating out long-wavelength density fluctuations. The system consists of Ndistinguishable spatially uniform Bose gases with \text{U}(N)symmetric...