Worst-Case Learning under a Multi-fidelity Model

Fuente: arXiv
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Main Authors: Foucart, Simon, Hengartner, Nicolas
Format: Preprint
Published: 2024
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author Foucart, Simon
Hengartner, Nicolas
author_facet Foucart, Simon
Hengartner, Nicolas
contents Inspired by multi-fidelity methods in computer simulations, this article introduces procedures to design surrogates for the input/output relationship of a high-fidelity code. These surrogates should be learned from runs of both the high-fidelity and low-fidelity codes and be accompanied by error guarantees that are deterministic rather than stochastic. For this purpose, the article advocates a framework tied to a theory focusing on worst-case guarantees, namely Optimal Recovery. The multi-fidelity considerations triggered new theoretical results in three scenarios: the globally optimal estimation of linear functionals, the globally optimal approximation of arbitrary quantities of interest in Hilbert spaces, and their locally optimal approximation, still within Hilbert spaces. The latter scenario boils down to the determination of the Chebyshev center for the intersection of two hyperellipsoids. It is worth noting that the mathematical framework presented here, together with its possible extension, seems to be relevant in several other contexts briefly discussed.
format Preprint
id arxiv_https___arxiv_org_abs_2406_14418
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Worst-Case Learning under a Multi-fidelity Model
Foucart, Simon
Hengartner, Nicolas
Numerical Analysis
65D15, 68Q99, 90C22, 90C47
Inspired by multi-fidelity methods in computer simulations, this article introduces procedures to design surrogates for the input/output relationship of a high-fidelity code. These surrogates should be learned from runs of both the high-fidelity and low-fidelity codes and be accompanied by error guarantees that are deterministic rather than stochastic. For this purpose, the article advocates a framework tied to a theory focusing on worst-case guarantees, namely Optimal Recovery. The multi-fidelity considerations triggered new theoretical results in three scenarios: the globally optimal estimation of linear functionals, the globally optimal approximation of arbitrary quantities of interest in Hilbert spaces, and their locally optimal approximation, still within Hilbert spaces. The latter scenario boils down to the determination of the Chebyshev center for the intersection of two hyperellipsoids. It is worth noting that the mathematical framework presented here, together with its possible extension, seems to be relevant in several other contexts briefly discussed.
title Worst-Case Learning under a Multi-fidelity Model
topic Numerical Analysis
65D15, 68Q99, 90C22, 90C47
url https://arxiv.org/abs/2406.14418