Tim A. Werthmann, M.Sc.

Institut für Geometrie und Praktische Mathematik
RWTH Aachen
Templergraben 55
52056 Aachen
Germany

advisor:

Lars Grasedyck

office:

Hauptgebäude 103

phone:

+49 241 80-93064

email:

werthmann@igpm.rwth-aachen.de

L. Grasedyck, T. A. Werthmann
Operator-dependent prolongation and restriction for the parameter-dependent multigrid method using low-rank tensor formats
Submitted, 2024.
L. Grasedyck, T. A. Werthmann
Computing tensor operator exponentials within low-rank tensor formats with application to the parameter-dependent multigrid method
In: PAMM 22: e202200093 (2023)
A. Rörich, T. A. Werthmann, D. Göddeke, L. Grasedyck
Bayesian inversion for electromyography using low-rank tensor formats
In: Inverse Problems 37.5 (2021)
L. Grasedyck, M. Klever, C. Löbbert, T. A. Werthmann
A parameter-dependent smoother for the multigrid method
Forthcoming in International Journal of Computing and Visualization in Science and Engineering, 2019.

Low-rank tensor formats
Preconditioning techniques for tensor problems
Computation of extremal eigenvalues of tensor operators
Exponential sums and the computation of the tensor exponential
Multigrid methods for parameter-dependent problems
High-dimensional problems in medical applications, for example, parameter-dependent EEG leadfield matrices
Fast C++ implementation of iterative solvers in hierarchical tensor formats

21st to 25th October 2024
Participant and Poster Presenter at the Workshop Nonlinear Approximation, PDEs and High-Dimensional Problems
3rd to 5th April 2024
Co-Organizer and Participant at The ABCs of Sparsity and Singular Structures
26th to 29th February 2024
Participant and Poster Presenter at the Symposium on Sparsity and Singular Structures 2024
13th to 15th September 2023
Organizer of and Speaker at the 10th Workshop on Matrix Equations and Tensor Techniques (METT X)
20th to 25th August 2023
Speaker at the ICIAM 2023 Tokyo
22nd to 26th May 2023
Participant and Poster Presenter in the Spring School on Sparsity and Singular Structures 2023
15th to 19th August 2022
Speaker at the GAMM Annual Meeting 2022
9th to 10th September 2021
Speaker at the Matrix Equations and Tensor Techniques IX (METTIX)
24th to 28th February 2020
Research visit at the University of Stuttgart, where I presented a talk about "Low-rank tensor methods for the electromyographic problem"
6th to 8th November 2019
Speaker at the METT VIII - 8th Workshop on Matrix Equations and Tensor Techniques, where I presented the following slides
17th to 30th June 2019
Participant and Poster Presenter in the Gene Golub SIAM Summer School 2019
4th to 8th March 2019
Participant in the Winterschool on Hierarchical Matrices 2019

Winter semester 2024/25
Functional Analysis as Assistant
Summer semester 2024
Mathematisches Praktikum as Assistant, Examiner, and Lecturer
Winter semester 2023/24
Functional Analysis as Assistant
Summer semester 2023
Mathematisches Praktikum as Assistant, Examiner, and Lecturer
Winter semester 2022/23
Functional Analysis as Assistant

Summer semester 2022
Mathematisches Praktikum as Assistant, Examiner, and Lecturer
Winter semester 2021/22
Functional Analysis as Assistant

Summer semester 2021
Mathematisches Praktikum as Assistant, Examiner, and Lecturer
Winter semester 2020/21
Functional Analysis as Assistant
Summer semester 2020
Mathematisches Praktikum as Assistant, Examiner, and Lecturer
Supervision of a Bachelor thesis
Winter semester 2019/20
Mathematics I (f. Civil Engineers a.o.) as Assistant
Supervision of two Bachelor seminars

Summer semester 2019
Mathematics II (f. Civil Engineers a.o.) as Assistant

Master of Science in Mathematics at RWTH Aachen
Thesis title: Multiparametric Representation of EEG Leadfield Matrices
Supervisor: Prof. Dr. Lars Grasedyck
Bachelor of Science in Mathematics at RWTH Aachen
Thesis title: An Efficient Method for Binary Classification by means of Logistic Regression and Tensor Format Representation
Supervisor: Prof. Dr. Mike Espig