Deep learning reveals hidden interactions in complex systems
This work addresses the challenge of inferring micro-dynamics in complex systems for researchers in fields like physics and biology, offering a novel data-driven approach that outperforms conventional methods.
The authors tackled the problem of modeling hidden interactions in complex systems from observed data, proposing AgentNet, a deep learning framework that successfully captured interactions in simulated systems like cellular automata and the Vicsek model, and identified hidden interaction ranges in empirical bird flock data.
Rich phenomena from complex systems have long intrigued researchers, and yet modeling system micro-dynamics and inferring the forms of interaction remain challenging for conventional data-driven approaches, being generally established by human scientists. In this study, we propose AgentNet, a model-free data-driven framework consisting of deep neural networks to reveal and analyze the hidden interactions in complex systems from observed data alone. AgentNet utilizes a graph attention network with novel variable-wise attention to model the interaction between individual agents, and employs various encoders and decoders that can be selectively applied to any desired system. Our model successfully captured a wide variety of simulated complex systems, namely cellular automata (discrete), the Vicsek model (continuous), and active Ornstein--Uhlenbeck particles (non-Markovian) in which, notably, AgentNet's visualized attention values coincided with the true interaction strength and exhibited collective behavior that was absent in the training data. A demonstration with empirical data from a flock of birds showed that AgentNet could identify hidden interaction ranges exhibited by real birds, which cannot be detected by conventional velocity correlation analysis. We expect our framework to open a novel path to investigating complex systems and to provide insight into general process-driven modeling.