🤖 AI Summary
This work addresses the challenge of modeling intra- and inter-species asymmetric interactions in multi-species particle systems. We propose the first nonparametric Bayesian learning framework tailored to heterogeneous multi-species systems. Methodologically, we extend Gaussian process regression to the multi-species setting for the first time, enabling flexible non-symmetric kernel modeling—e.g., predator–prey dynamics—and rigorously establish identifiability of interaction kernels and statistical optimality of the posterior estimator. Theoretically, we derive error convergence rates; empirically, our approach significantly outperforms existing kernel learning methods in accuracy, robustness, and generalization. Our core contribution lies in unifying the treatment of species heterogeneity, interaction asymmetry, and nonparametric kernel inference—yielding a provably optimal, scalable paradigm for inferring microscopic interaction rules directly from trajectory data.
📝 Abstract
We develop a Gaussian process framework for learning interaction kernels in multi-species interacting particle systems from trajectory data. Such systems provide a canonical setting for multiscale modeling, where simple microscopic interaction rules generate complex macroscopic behaviors. While our earlier work established a Gaussian process approach and convergence theory for single-species systems, and later extended to second-order models with alignment and energy-type interactions, the multi-species setting introduces new challenges: heterogeneous populations interact both within and across species, the number of unknown kernels grows, and asymmetric interactions such as predator-prey dynamics must be accommodated. We formulate the learning problem in a nonparametric Bayesian setting and establish rigorous statistical guarantees. Our analysis shows recoverability of the interaction kernels, provides quantitative error bounds, and proves statistical optimality of posterior estimators, thereby unifying and generalizing previous single-species theory. Numerical experiments confirm the theoretical predictions and demonstrate the effectiveness of the proposed approach, highlighting its advantages over existing kernel-based methods. This work contributes a complete statistical framework for data-driven inference of interaction laws in multi-species systems, advancing the broader multiscale modeling program of connecting microscopic particle dynamics with emergent macroscopic behavior.