School of Mathematical & Statistical Sciences Faculty Publications

Document Type

Article

Publication Date

9-30-2026

Abstract

The Kolmogorov n-width is an established benchmark to judge the approximation properties of the reduced linear spaces arising from reduced order models (ROMs). Although immensely successful in the elliptic regime, this width shows unsatisfactory slow convergence rates for transport dominated problems. While this has triggered a large amount of work on nonlinear model reduction techniques, we are lacking a benchmark to evaluate their optimal performance. Simply replacing the Kolmogorov n-width of the solution manifold with nonlinear benchmarks, like manifold/stable/Lipschitz width, does generally not provide satisfactory results: The performance bounds tend to be trivial if the degrees of freedom exceed the parameter dimension. Furthermore, without linearity, nonlinear width lack structure to implement corresponding online/offline decompositions. This paper introduces a different perspective, where the nonlinear widths are applied to the full reduced order model pipeline from PDE to parametric quantity of interest. We prove that this alternative view provides informative nonlinear benchmarks for transport equations.

Comments

This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. 

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Publication Title

Constructive Approximation

DOI

10.1007/s00365-026-09784-1

Included in

Mathematics Commons

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.