Research

Research interests

  • Numerical Analysis, Hyperbolic PDEs and conservation laws
  • Unconditionally positive and structure-preserving numerical methods
  • Stability of nonlinear methods
  • Positivity-preserving Dense Output formulae
  • Optimal time step control and parameter estimation using ML

Participation in funded research projects

09/2026 - 02/2028

Stable Residual Distribution schemes using Unconditionally Positive methods (STARD-UP)

Role: Applicant and PI, DAAD PRIME

01/2026 - 07/2026

Unconditionally Positive Numerical Schemes preserving Entropy Properties via Relaxation

Role: Applicant and PI, Fulbright Germany

01/2026 - 07/2026

Unconditionally Positive Numerical Schemes preserving Entropy Properties via Relaxation

Role: Applicant and PI, DAAD

09/2025 - 11/2025Modeling and numerical simulation of pandemic processes in Ghana using a modified Patankar–Runge–Kutta methods
Role: Co-writing the proposal and co-collaborator, German Research Foundation
07/2021 - 06/2024Significant expansion and unification of the theory of Patankar-type methods through uniform order analysis, first-time investigation of stability, time step adaptation, and dense output formulae
Role: Co-writing the proposal and main investigator of the research, German Research Foundation

Supervision

02/2023 - todayCo-supervising Ph.D. students, Kassel
08/2022 - 08/2026Mentoring Bachelor's and Master's students, Kassel

Other experience of relevance

02/2023 - todayCo-supervising 1 Ph.D. student, Kassel
12/2023 - 06/2025Reviewer for international journals: SIAM J. Sci. Comput., J. Comput. Sci.,
J. Comput. Appl. Math., Appl. Numer. Math.
08/2022 - 03/2023Mentored 1 Master's student, Kassel

Publications

Peer-reviewed in international journals

13. Using Machine Learning to Enhance Pandemic Modeling: Case study of COVID-19 Dynamics in Ghana
(with A. Meister, I. Azure)
Journal of Mathematics in Industry (2026)
[DOI]
12. The Lax–Wendroff theorem for Patankar-type methods applied to hyperbolic conservation laws
(with J. Bender, D. Torlo, P. Öffner)
Computers & Fluids (2026)
[DOI]
11. A Boot-Strapping Technique to Design Unconditionally Positive Dense Output Formulae for Modified Patankar-Runge-Kutta Methods
Communications on Applied Mathematics and Computation (2025).
[DOI]
10. Order conditions for Runge-Kutta-like methods with solution-dependent coefficients
(with D. Ketcheson, A. Meister)
Communications in Applied Mathematics and Computational Science, 20 (1), (2025), 29-66.
[DOI]
9. On the non-global linear stability and spurious fixed points of MPRK schemes with negative RK parameters
(with S. Kopecz, A. Meister, A. Schilling)
Numerical Algorithms, 96, (2024), 1221-1242.
[DOI]
8. A necessary condition for non-oscillatory and positivity preserving time-integration schemes
(with D. Torlo, P. Öffner)
In: Hyperbolic Problems: Theory, Numerics, Applications. Volume II, SEMA SIMAI Springer Ser., Vol. 35, Springer, Cham (2024), 121-131.
[DOI]
7. On the local dynamics of first and second order GeCo and gBBKS schemes
(with S. Kopecz, A. Martiradonna, A. Meister)
Applied Numerical Mathematics, 193, (2023), 43-66.
[DOI]
6. A study of the local dynamics of modified Patankar DeC and higher order modified Patankar-RK methods
(with P. Öffner)
ESAIM: M2AN, 57, (2023), 2319-2348.
[DOI]
5. On the Stability of Strong-Stability-Preserving modified Patankar-Runge-Kutta schemes
(with J. Huang, S. Kopecz, A. Meister, C.-W. Shu)
ESAIM: M2AN, 57, (2023), 1063-1086.
[DOI]
4. On the Stability of Unconditionally Positive and Linear Invariants Preserving Time Integration Schemes
(with S. Kopecz, A. Meister)
SIAM Journal on Numerical Analysis, 60 (6), (2022), 3029-3051.
[DOI]
3. On Lyapunov stability of positive and conservative time integrators and application to second order modified Patankar-Runge-Kutta schemes
(with S. Kopecz, A. Meister)
ESAIM: M2AN, 56 (3), (2022), 1053-1080.
[DOI]
2. An Involutive GVW Algorithm and the Computation of Pommaret Bases
(with A. Hashemi, D. Robertz, W. M. Seiler)
Mathematics in Computer Science, 15, (2021), 419-452.
[DOI]
1. Numerical Investigation of Ultrashort Laser-Ablative Synthesis of Metal Nanoparticles in Liquids Using the Atomistic-Continuum Model
(with D. S. Ivanov, A. N. Maiorov, V. P. Veiko, B. Rethfeld, Y. I. Dombrovska, A. V. Kabashin)
Molecules, 25 (1), (2020), 67-78.
[DOI]

Peer-reviewed Conference Proceedings

2. A Stability Analysis of Modified Patankar-Runge-Kutta methods for a nonlinear Production-Destruction System
(with S. Kopecz, A. Meister)
PAMM, 22: e202200083 (2023)
[DOI]
1. Recent Developments in the Field of Modified Patankar-Runge-Kutta methods
(with S. Kopecz, A. Meister)
PAMM, 21: e202100027 (2021)
[DOI]

Thesis

A Unifying Theory for Runge-Kutta-like Time Integrators: Convergence and Stability
PhD Thesis, University of Kassel, KOBRA (2024). 

[DOI] (Not available due to an embargo - will be published soon by Springer.)

Arxiv-version: [DOI]

Preprints

2. Flux-Balanced Patankar-type Schemes for the Compressible Euler Equations (Accepted in Communications on Applied Mathematics and Computation (CAMC))
(with A. Meister, D. Torlo, C.-W. Shu)
(2026)
[DOI]
1. A Positivity-Preserving Relaxation Algorithm
(with H. Ranocha, C.-W. Shu)
(2026)
[DOI]