Effects of time-delay couplings in the collective frequency of network oscillations

TL;DR

This paper investigates how time delays in coupling affect the collective frequency of synchronized oscillators in networks, revealing dependencies on coupling strength, delay distribution, and system heterogeneity.

Contribution

It analytically explores the impact of fixed and distributed time delays on the collective frequency in both identical and non-identical oscillator systems using the Kuramoto model.

Findings

Collective frequency depends on coupling strength and time delay.

Positive coupling generally decreases frequency, negative increases it.

Distributed delays can induce bifurcations and new system behaviors.

Abstract

In this study, we construct such systems with the Kuramoto model of globally coupled oscillators with time-delayed positive and negative couplings to explore the impact of coupling time delays in the collective frequency of synchronized oscillations. We discuss various identical and nonidentical systems with fixed and exponential distributed delays and derive relationships between the coupling delay and collective frequency for a stably synchronized state. For the nonidentical system of coupled oscillators, we consider the Lorentzian distribution of intrinsic frequencies and exponential distributions of coupling time delays in coupled oscillators, and analytically derived the collective frequency-time delay relationship. We found that the collective frequency of the network oscillations is dependent on both coupling strength and time delay. In identical cases, the network frequency decreases in most cases of positive coupling and increases in a negative coupling with increasing. In non-identical cases with distributed delays, along with the modulations in the network frequency, we discussed time-delay coupling can also lead to the appearance of bifurcations and transitions in the system's behavior resulting in the emergence of new patterns and the breakdown of existing ones. We discuss the implications of these results in understanding the behaviors of the natural systems.