We analyze local operator growth in nonintegrable quantum many-body systems. A recently
introduced universal operator growth hypothesis proposes that the maximal growth of …

The aim of this paper is to provide better understanding of a few approaches that have been
proposed for treating nonequilibrium (time-dependent) processes in statistical mechanics …

The dynamics of quantum systems unfolds within a subspace of the state space or operator
space, known as the Krylov space. This review presents the use of Krylov subspace …

We investigate the dynamical behavior of a classical harmonic-oscillator chain with periodic
and fixed-end boundary conditions. The displacement and velocity autocorrelation functions …

We generalize the method of Van Hove [Physica (Amsterdam) 21, 517 (1955)] so as to deal
with the case of nonordinary statistical mechanics, that being phenomena with no time-scale …

We review various theoretical methods that have been used in recent years to calculate
dynamical correlation functions of many-body systems. Time-dependent correlation …

We investigate the dynamics of the one-dimensional S=(1/2) isotropic XY model and
transverse Ising model in the high-temperature limit by using the method of recurrence …

There is an exact equivalence in the time-dependent behaviour of a zero-temperature two-
dimensional interacting electron gas at long wavelengths and a classical harmonic oscillator …

Two perturbation methods are compared for the theories of the cyclotron resonance line
shape for electron-phonon systems. The line-shape functions in schemes designated as …

A general expression for the response function is derived by the method of recurrence
relations. Memory effects appear as corrections to the dynamic random-phase …