2025/05/13 by Tianyu Jin, Jin, Tianyu, Zhichao Peng +3
Engineering · Mathematics · Physics and Astronomy · #Computational Physics (physics.comp-ph) #Control and Stability of Dynamical Systems #Convection–diffusion equation #Diffusion #FOS: Mathematics #FOS: Physical sciences #Limit (mathematics) #Model Reduction and Neural Networks #Nonlinear system #Numerical Analysis (math.NA) #Numerical methods for differential equations #Parametric statistics #Piecewise #Piecewise linear function
paper · pdf · doi:10.48550/arxiv.2505.08214
published in arXiv (Cornell University) (Cornell University)
openalex publication_date 2025/05/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
In this work, we develop reduced order models (ROMs) to predict solutions to a multiscale kinetic transport equation with a diffusion limit under the parametric setting. When the underlying scattering effect is not sufficiently strong, the system governed by this equation exhibits transport-dominated behavior. Suffering from the Kolmogorov barrier for transport-dominant problems, classical linear ROMs may become inefficient in this regime. To address this issue, we first develop a piecewise linear ROM by introducing a novel goal-oriented adaptive time partitioning strategy. To avoid local over-refinement or under-refinement, we propose an adaptive coarsening and refinement strategy that remains robust with various initial empirical partitions. Additionally, for problems where a local linear approximation is not sufficiently efficient, we further develop a hybrid ROM, which combines autoencoder-based nonlinear ROMs and piecewise linear ROMs. Compared to previous autoencoder-based ROMs, this hybridized method reduces the offline autoencoder's training cost by only applying it to time intervals that are adaptively identified as the most challenging. Numerical experiments demonstrate that our proposed approaches successfully predict full-order solutions at unseen parameter values with both efficiency and accuracy. To the best of our knowledge, this is the first attempt to address the Kolmogorov barrier for multiscale kinetic transport problems with the coexistence of both transport- and diffusion-dominant behaviors.