Exact results for anomalous transport in one dimensional Hamiltonian systems

TL;DR

This paper demonstrates that anomalous transport in one-dimensional Hamiltonian systems with short-range interactions generally falls into the KPZ universality class, providing exact asymptotic correlation functions and analyzing the applicability of mode coupling theories.

Contribution

It provides exact asymptotic forms for correlation functions in 1D Hamiltonian systems and clarifies the applicability of mode coupling theories across different interaction strengths.

Findings

Anomalous transport belongs to the KPZ universality class.

Exact asymptotic forms for correlation functions are derived.

Mode coupling theories are adequate for weakly nonlinear chains but need corrections for strongly anharmonic potentials.

Abstract

Anomalous transport in one dimensional translation invariant Hamiltonian systems with short range interactions, is shown to belong in general to the KPZ universality class. Exact asymptotic forms for density-density and current-current time correlation functions and their Fourier transforms are given in terms of the Pr\"ahofer-Spohn scaling functions, obtained from their exact solution for the Polynuclear growth model. The exponents of corrections to scaling are found as well, but not so the coefficients. Mode coupling theories developed previously are found to be adequate for weakly nonlinear chains, but in need of corrections for strongly anharmonic interparticle potentials.