Breakdown of stochastic resonance in complex networks.

Area of Science:

• Complex systems
• Nonlinear dynamics
• Statistical physics

Background:

• Stochastic resonance (SR) is a collective phenomenon in networked systems.
• SR depends on oscillator resonance capacity, network coupling, signal amplitude, and noise intensity.
• The impact of local oscillator defects on network-wide SR is not well understood.

Purpose of the Study:

• To investigate if local defects in oscillator resonance capacity can break down network-wide stochastic resonance.
• To analyze the influence of nonresonant oscillators on the collective SR phenomenon.
• To explore the roles of network topology and coupling strength in maintaining or suppressing SR.

Main Methods:

• Studied complex networks of bistable oscillators in a double-well potential.
• Introduced a fraction of oscillators with nonresonant potential landscapes.
• Analyzed the dependence of SR sustainability on the number and dissimilarity of nonresonant oscillators, network topology, and coupling strength.

Main Results:

• The number of nonresonant oscillators required to break SR depends nonlinearly on their dissimilarity from other oscillators.
• Network topology and coupling strength play crucial roles in determining SR robustness against local defects.
• A low-dimensional deterministic model was developed that confirms the network simulation results.

Conclusions:

• Local defects in oscillator resonance capacity can indeed disrupt network-wide stochastic resonance.
• The system's resilience to defects is tunable via network structure and coupling.
• Findings provide insights into the fragility and robustness of collective phenomena in complex networks.