🤖 AI Summary
Identifying latent states and decoupling dynamic modes in stochastic nonlinear dynamical systems remains challenging due to inherent nonlinearity and randomness.
Method: This paper proposes a hidden Markov operator representation framework embedded in a reproducing kernel Hilbert space (RKHS). It uniquely integrates stochastic realization theory with kernel embedding techniques to jointly learn latent-space structure and state-transition operators; extends the Kalman filter to nonlinear stochastic systems; and introduces operator-theoretic dynamic mode decomposition (O-DMD). The technical pipeline encompasses spectral learning, neural-network-based adaptive kernel construction, generalized sequential state estimation, and operator spectral analysis.
Results: Evaluated on synthetic and real-world datasets, the method significantly improves latent-state estimation accuracy, enables interpretable and decoupled extraction of dynamical modes, and establishes a unified, robust, and interpretable paradigm for modeling and inference in stochastic nonlinear systems.
📝 Abstract
We consider an operator-based latent Markov representation of a stochastic nonlinear dynamical system, where the stochastic evolution of the latent state embedded in a reproducing kernel Hilbert space is described with the corresponding transfer operator, and develop a spectral method to learn this representation based on the theory of stochastic realization. The embedding may be learned simultaneously using reproducing kernels, for example, constructed with feed-forward neural networks. We also address the generalization of sequential state-estimation (Kalman filtering) in stochastic nonlinear systems, and of operator-based eigen-mode decomposition of dynamics, for the representation. Several examples with synthetic and real-world data are shown to illustrate the empirical characteristics of our methods, and to investigate the performance of our model in sequential state-estimation and mode decomposition.