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Signal reconstruction using determinantal sampling

delete2025-11-03
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PRE
AI
A
Ayoub Belhadji
R
Rémi Bardenet
P
Pierre Chainais
DOI:10.1016/j.acha.2025.101822delete
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Abstract

Abstract

En 中文
We study the approximation of a square-integrable function from a finite number of evaluations on a random set of nodes according to a well-chosen distribution. This is particularly relevant when the function is assumed to belong to a reproducing kernel Hilbert space (RKHS). This work proposes to combine several natural finite-dimensional approximations based on two possible probability distributions of nodes. These distributions are related to determinantal point processes, and use the kernel of the RKHS to favor RKHS-adapted regularity in the random design. While previous work on determinantal sampling relied on the RKHS norm, we prove mean-square guarantees in L2 norm. We show that determinantal point processes and mixtures thereof can yield fast convergence rates. Our results also shed light on how the rate changes as more smoothness is assumed, a phenomenon known as superconvergence. Besides, determinantal sampling improves on i.i.d. sampling from the Christoffel function which is standard in the literature. More importantly, determinantal sampling guarantees the so-called instance optimality property for a smaller number of function evaluations than i.i.d. sampling.

Journal

Applied and Computational Harmonic Analysis cover
Applied and Computational Harmonic Analysis
IF:
3.2
Papers:
95
Citations:
3.9K

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