One-shot learning of stochastic differential equations with data adapted kernels

M Darcy, B Hamzi, G Livieri, H Owhadi… - Physica D: Nonlinear …, 2023 - Elsevier
We consider the problem of learning Stochastic Differential Equations of the form d X t= f (X
t) d t+ σ (X t) d W t from one sample trajectory. This problem is more challenging than …

[HTML][HTML] Learning dynamical systems from data: A simple cross-validation perspective, part iv: case with partial observations

B Hamzi, H Owhadi, Y Kevrekidis - Physica D: Nonlinear Phenomena, 2023 - Elsevier
A simple and interpretable way to learn a dynamical system from data is to interpolate its
governing equations with a kernel. In particular, this strategy is highly efficient (both in terms …

[PDF][PDF] Learning dynamical systems from data: a simple cross-validation perspective, part ii: nonparametric kernel flows

M Darcy, B Hamzi, J Susiluoto, A Braverman… - …, 2021 - users.cms.caltech.edu
In previous work, we showed that learning dynamical system [21] with kernel methods can
achieve state of the art, both in terms of accuracy and complexity, for predicting …

Learning dynamical systems from data: A simple cross-validation perspective, part v: Sparse kernel flows for 132 chaotic dynamical systems

L Yang, X Sun, B Hamzi, H Owhadi, N Xie - arXiv preprint arXiv …, 2023 - arxiv.org
Regressing the vector field of a dynamical system from a finite number of observed states is
a natural way to learn surrogate models for such systems. A simple and interpretable way to …

Kernel sum of squares for data adapted kernel learning of dynamical systems from data: A global optimization approach

D Lengyel, P Parpas, B Hamzi, H Owhadi - arXiv preprint arXiv …, 2024 - arxiv.org
This paper examines the application of the Kernel Sum of Squares (KSOS) method for
enhancing kernel learning from data, particularly in the context of dynamical systems …

[HTML][HTML] Simplicity bias, algorithmic probability, and the random logistic map

B Hamzi, K Dingle - Physica D: Nonlinear Phenomena, 2024 - Elsevier
Simplicity bias is an intriguing phenomenon prevalent in various input–output maps,
characterized by a preference for simpler, more regular, or symmetric outputs. Notably, these …

Gaussian processes simplify differential equations

J Lee, B Hamzi, Y Kevrekidis, H Owhadi - arXiv preprint arXiv:2410.03003, 2024 - arxiv.org
In this paper we use Gaussian processes (kernel methods) to learn mappings between
trajectories of distinct differential equations. Our goal is to simplify both the representation …

Kernel methods for the approximation of some key quantities of nonlinear systems

J Bouvrie, B Hamzi - Journal of Computational Dynamics, 2017 - aimsciences.org
We introduce a data-based approach to estimating key quantities which arise in the study of
nonlinear control systems and random nonlinear dynamical systems. Our approach hinges …

Learning dynamical systems from data: A simple cross-validation perspective, Part III: Irregularly-sampled time series

J Lee, E De Brouwer, B Hamzi, H Owhadi - Physica D: Nonlinear …, 2023 - Elsevier
A simple and interpretable way to learn a dynamical system from data is to interpolate its
vector-field with a kernel. In particular, this strategy is highly efficient (both in terms of …

Learning dynamical systems from data: a simple cross-validation perspective, part iii: irregularly-sampled time series

J Lee, E De Brouwer, B Hamzi, H Owhadi - arXiv preprint arXiv …, 2021 - arxiv.org
A simple and interpretable way to learn a dynamical system from data is to interpolate its
vector-field with a kernel. In particular, this strategy is highly efficient (both in terms of …