From laser cooling to aging: A unified Lévy flight description

What phenomena such as the subrecoil laser cooling of atoms and aging in glasses have in common is that these systems do not reach steady state during experimental observations, although the observation times are very large compared to microscopic time scales. We discuss some standard models that describe these phenomena and reformulate them in a unified framework in terms of the occupation times of the microscopic states of the system. A universal dynamical mechanism emerges, leading to a generic time-dependent distribution of occupation times, independent of the physical system considered.