Decay Of Time Correlations Research Articles

Decay of time correlations in point vortex systems

The dynamics of a large point vortex system whose initial configuration consists in uniformly distributed independent positions is investigated. Time correlations of local observables of the vortex configuration are shown to be compatible with power law decay 1/t, providing additional insight on ergodicity and mixing properties of equilibrium dynamics in point vortex models.

Heterogeneous Structure, Heterogeneous Dynamics, and Complex Behavior in Two-Dimensional Liquids.

Analysis of the metrical and topological features of the local structure in a freezing two-dimensional Lennard-Jones system found that in a narrow strip [Formula: see text] of thermodynamic states close to the melting line, the liquid becomes a complex liquid characterized by a super-Arrhenius increase of relaxation times, stretched-exponential decay of correlations in time, and a power-law distribution of waiting times for changes in the local order. In [Formula: see text], the structure of the liquid and its dynamics are spatially heterogeneous; the sizes of ordered clusters are power-law distributed. Those features are governed by local structure evolution between solid-like and liquid-like (disordered) patterns. The liquid inside the strip [Formula: see text] gives a unique opportunity to study how heterogeneous structure, dynamics and complexity are intertwined with each other on a microscopic level.

Decay of Time Correlations in Two Dimensions

Molecular-dynamic studies of the kinetic correlation functions for shear viscosity and heat conductivity of hard disks are consistent with the asymptotic reciprocal time behavior $\frac{1}{S}$ predicted by hydrodynamics. However, this hydrodynamic description, which predicts divergent transport coefficients, must be made self-consistent by introducing time-dependent transport coefficients, leading to a decay of $\frac{1}{S\sqrt{(\mathrm{ln}S)}}$, indistinguishable from the $\frac{1}{S}$ behavior. The hydrodynamic model predicts no such long-time behavior for the potential contributions.