
Karl Welzel
DPhil Candidate in Mathematics
Pronouns
He / Him
Status
Postgraduate Student
Research groups
Address
Mathematical Institute
University of Oxford
Andrew Wiles Building
Radcliffe Observatory Quarter
Woodstock Road
Oxford
OX2 6GG
University of Oxford
Andrew Wiles Building
Radcliffe Observatory Quarter
Woodstock Road
Oxford
OX2 6GG
Major / recent publications
W. and Raphael A. Hauser: "Approximating Higher-Order Derivative Tensors Using Secant Updates" (published in SIAM Journal on Optimization on 28 February 2024, preprint on arXiv)
- Presented at the Numerical Analysis Group Internal Seminar on 21 February 2023
- Presented at the SIAM Conference on Optimization in Seattle on 3 June 2023 as part of the mini-symposium "Algorithms for Nonlinear Optimization"
- Presented at the Biennial Numerical Analysis Conference in Glasgow on 28 June 2023 as a contributed talk
- Presented at the International Congress on Industrial and Applied Mathematics in Tokyo on 24 August 2023 as a contributed talk
- Presented at the International Symposium on Mathematical Programming in Montreal on 25 July 2024 as part of the mini-symposium "Nonlinear Programming for Data Science" (Slides)
- Presented at the Annual Conference OR66 of the British OR Society in Bangor on 11 September 2024 (Slides)
Coralia Cartis, Raphael A. Hauser, Yang Liu, Karl Welzel, Wenqi Zhu: "Efficient Implementation of Third-order Tensor Methods with Adaptive Regularization for Unconstrained Optimization" (preprint on arXiv)
Coralia Cartis, Raphael A. Hauser, Yang Liu, W.: "Convergence of adaptively regularized tensor methods" (in preparation)
- Presented at the Numerical Analysis Group Internal Seminar on 21 November 2024 (Slides)
- Presented at the EUROPT 2025 Conference in Southampton on 1 July 2025 (Slides)
Teaching
- Teaching Assistant for C6.2 Continuous Optimization (Hilary Term 2022)
- Teaching Assistant for B6.3 Integer Programming (Michealmas Term 2022)
- Tutor and Teaching Assistant for B6.3 Integer Programming (Michealmas Term 2023)
- Tutor and Teaching Assistant for C6.2 Continuous Optimization (Hilary Term 2024)
- Tutor and Teaching Assistant for B6.3 Integer Programming (Michealmas Term 2024)
- Demonstrator for Computational Mathematics in Python (Michealmas Term 2024)
- Tutor and Teaching Assistant for C6.2 Continuous Optimization (Hilary Term 2025)
Research interests
- Higher-order continuous optimization (involving three or more derivatives)
- Convergence analysis of continuous optimization methods
- Tensor representations and approximations