The onset of synchronization in large networks of coupled oscillators

TL;DR

This paper investigates the transition to synchronization in large networks of coupled oscillators, providing new theoretical insights and approximations that relate the critical coupling to the network's eigenvalues, validated by simulations.

Contribution

It generalizes the critical coupling strength calculation using eigenvalues and connects mean field approximations to network spectral properties.

Findings

Critical coupling linked to largest eigenvalue of adjacency matrix

Mean field approximation derived from spectral analysis

Finite size effects increase critical coupling strength

Abstract

We study the transition from incoherence to coherence in large networks of coupled phase oscillators. We present various approximations that describe the behavior of an appropriately defined order parameter past the transition, and generalize recent results for the critical coupling strength. We find that, under appropriate conditions, the coupling strength at which the transition occurs is determined by the largest eigenvalue of the adjacency matrix. We show how, with an additional assumption, a mean field approximation recently proposed is recovered from our results. We test our theory with numerical simulations, and find that it describes the transition when our assumptions are satisfied. We find that our theory describes the transition well in situations in which the mean field approximation fails. We study the finite size effects caused by nodes with small degree and find that they cause the critical coupling strength to increase.