Low Dimensional Dynamics of the Kuramoto Model with Rational Frequency Distributions

TL;DR

This paper extends the analysis of the Kuramoto model's collective dynamics to rational frequency distributions, deriving low-dimensional equations that reveal synchronization transitions and stability properties beyond the Lorentzian case.

Contribution

It introduces a method to analyze low-dimensional dynamics for a broader class of frequency distributions in the Kuramoto model, beyond the Lorentzian case.

Findings

Critical coupling strength for synchronization is analytically derived.

System dynamics remain simple despite increasing distribution complexity.

The approach enables stability analysis and bifurcation categorization.

Abstract

The Kuramoto model is a paradigmatic tool for studying the dynamics of collective behavior in large ensembles of coupled dynamical systems. Over the past decade a great deal of progress has been made in analytical descriptions of the macroscopic dynamics of the Kuramoto mode, facilitated by the discovery of Ott and Antonsen's dimensionality reduction method. However, the vast majority of these works relies on a critical assumption where the oscillators' natural frequencies are drawn from a Cauchy, or Lorentzian, distribution, which allows for a convenient closure of the evolution equations from the dimensionality reduction. In this paper we investigate the low dimensional dynamics that emerge from a broader family of natural frequency distributions, in particular a family of rational distribution functions. We show that, as the polynomials that characterize the frequency distribution increase in order, the low dimensional evolution equations become more complicated, but nonetheless the system dynamics remain simple, displaying a transition from incoherence to partial synchronization at a critical coupling strength. Using the low dimensional equations we analytically calculate the critical coupling strength corresponding to the onset of synchronization and investigate the scaling properties of the order parameter near the onset of synchronization. These results agree with calculations from Kuramoto's original self-consistency framework, but we emphasize that the low dimensional equations approach used here allows for a true stability analysis categorizing the bifurcations.