EUROPT 2025
Abstract Submission

109. Efficient Adaptive Regularized Tensor Methods

Invited abstract in session WB-2: High-order and tensor methods, stream Nonsmooth and nonconvex optimization.

Wednesday, 10:30-12:30
Room: B100/7011

Authors (first author is the speaker)

1. Yang Liu
Mathematical Institute, University of Oxford
2. Karl Welzel
Mathematical Institute, University of Oxford
3. Coralia Cartis
Mathematical Institute, University of Oxford
4. Raphael Hauser
Oxford University Computing Laboratory, Oxford University
5. Wenqi Zhu
University of Oxford

Abstract

High-order tensor methods employing local Taylor approximations have attracted considerable attention for convex and nonconvex optimization. The pth-order adaptive regularization (ARp) approach builds a local model comprising a pth-order Taylor expansion and a (p+1)th-order regularization term, delivering optimal worst-case global and local convergence rates. However, for p≥2, subproblem minimization can yield multiple local minima, and while a global minimizer is recommended for p=2, effectively identifying a suitable local minimum for p≥3 remains elusive. This work extends interpolation-based updating strategies, originally proposed for p=2, to cases where p≥3, allowing the regularization parameter to adapt in response to interpolation models. Additionally, it introduces a new prerejection mechanism to discard unfavorable subproblem minimizers before function evaluations, thus reducing computational costs for p≥3. Numerical experiments, particularly on Chebyshev-Rosenbrock problems with p=3, indicate that the proper use of different minimizers can significantly improve practical performance, offering a promising direction for designing more efficient high-order methods.

Keywords

Status: accepted


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