Keywords

Carleman linearization, dynamical systems with periodic vector fields, permutation-equivariant dynamical systems, finite-section approximation, explicit error bounds

Abstract

Carleman linearization has been widely employed in mathematical modeling and control theory and it could be used to investigate the stability of nonlinear systems, particularly in situations requiring higher-order accuracy. The essence of Carleman linearization is to lift a finite-dimensional nonlinear system to an infinite-dimensional linear system.

We consider nonlinear dynamical systems with periodic vector fields with multiple fundamental frequencies. We employ Fourier basis functions for Carleman-Fourier linearization, a method that transforms these systems into an infinite-dimensional linear model with an unbounded operator. This approach provides more accurate approximations than classical Carleman linearization, particularly in larger regions around the equilibrium and over extended time periods. For certain classes of systems, we demonstrate that exponential convergence is achievable across the entire time horizon. Our results are practically significant, as our proposed error bound estimates can guide in computing proper truncation lengths for various applications, such as determining the appropriate sampling period for model predictive control, conducting reachability analysis for safety verifications, and developing efficient algorithms for quantum computing.

To apply Carleman linearization to engineering applications, we must address both its accuracy and efficiency, as the latter poses a significant challenge. We have proposed a permutation-equivariant Carleman linearization, called PeCaL, to reduce the dimension of the finite-section approximation of Carleman Linearization when the nonlinear system is permutation-equivariant. We compare the time costs between classical Carleman Linearization and PeCaL with the same truncation order through simulations, alongside the explicit error bounds as previous works.

Completion Date

2024

Semester

Summer

Committee Chair

Sun, Qiyu

Degree

Doctor of Philosophy (Ph.D.)

College

College of Sciences

Department

Department of Mathematics

Degree Program

Doctoral program in Mathematics

Format

application/pdf

Identifier

DP0028888

URL

https://stars.library.ucf.edu/cgi/viewcontent.cgi?article=1484&context=etd2023

Language

English

Rights

In copyright

Release Date

8-15-2026

Length of Campus-only Access

1 year

Access Status

Doctoral Dissertation (Campus-only Access)

Campus Location

Orlando (Main) Campus

Accessibility Status

Meets minimum standards for ETDs/HUTs

Restricted to the UCF community until 8-15-2026; it will then be open access.

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