Matthias Ostermann

I am a postdoctoral researcher in the research group of Irfan Glogić at the Faculty of Mathematics of Bielefeld University.

Previously, I held a praedoc position from the Vienna School of Mathematics at the University of Vienna.

I obtained my doctoral degree in Mathematics at the University of Vienna in 2025. My doctoral advisor is Roland Donninger. Before that, I graduated in the Master program in Mathematics and the Bachelor programs in Mathematics and Physics at the University of Vienna. Complementary to my master studies, I completed the Vienna Master Class Mathematical Physics.

Contact information

Universität Bielefeld
Universitätsstraße 25
33615 Bielefeld

Faculty of Mathematics
Office V4-229

E-mail address:	matthias.ostermann@uni-bielefeld.de
ORCID iD:	https://orcid.org/0009-0002-6538-5901

Research interests

I am interested in nonlinear partial differential equations of evolution type that arise in mathematical physics or geometry. My research explores the breakdown of their solutions. Currently, I study the existence, stability, and continuation of self-similar blowup in nonlinear wave equations. This combines ideas and techniques from semigroup theory, spectral theory, functional and harmonic analysis, and geometric analysis.

Research articles

1. (with R. Donninger) On stable self-similar blowup for corotational wave maps and equivariant Yang-Mills connections
   preprint 2024, submitted for publication. [arXiv:2409.14733]
2. Stable blowup for focusing semilinear wave equations in all dimensions
   Trans. Amer. Math. Soc. 377 (2024), pp. 4727-4778. [Journal article], [arXiv:2304.08187]
3. A characterization of the subspace of radially symmetric functions in Sobolev spaces
   Commun. Contemp. Math. 27 (2025), no. 3, Paper No. 2450018, 15 pp. [Journal article], [arXiv:2209.02286]
4. (with R. Donninger) A globally stable self-similar blowup profile in energy supercritical Yang-Mills theory
   Comm. Partial Differential Equations. 48 (2023), no. 9, 1148-1213. [Journal article], [arXiv:2108.13668]

PhD thesis

My dissertation is available online at u:theses.

Talks and conferences

• Oberseminar Analysis
  Bielefeld University, April 2025
• Workshop: Young researchers in deterministic and probabilistic dispersive equations
  Bernoulli Center, Lausanne, Switzerland, October 2024
• Thematic Programme: Nonlinear Waves and Relativity
  Erwin Schrödinger International Institute for Mathematics and Physics, May 2024
• VSM PhD Colloquium
  TU Wien, Austria, October 2023
• Research Seminar: One-Parameter Semigroups for Evolution Equations
  University of Innsbruck, Austria, June 2023
• Conference: Harmonic Analysis and Partial Differential Equations
  Bonn, Germany, May 2023
• Summer School 2022: Geometric dispersive PDEs
  Obergurgl, Austria, September 2022
• 2^nd IST Austria Summer School in Analysis and PDEs
  Klosterneuburg, Austria, July 2022
• Recent trends in nonlinear dispersive equations: equilibria, stability, dynamics
  Będlewo, Poland, May 2022.
• Young PDEs Mini Symposium
  University of Vienna, April 2022
• Vienna Master Class Mathematical Physics
  Erwin Schrödinger International Institute for Mathematics and Physics, April 2022

Teaching

• Summer 2025
  • Übungen zu Analysis II
    Bielefeld University, 4 hours
• Summer 2024
  • Proseminar Analysis 3
    University of Vienna, 2 hours
• Winter 2023
  • Proseminar Analysis 1
    University of Vienna, 1 hour
• Summer 2023
  • Proseminar Analysis 2
    University of Vienna, 2 hours
• Winter 2022
  • Tutorials on Partial Differential Equations
    University of Vienna, 1 hour
• Summer 2022
  • Tutorials on Functional Analysis
    University of Vienna, 1 hour
• Winter 2021
  • Exercises on Introduction to Mathematical Methodology
    University of Vienna, 1 hour
• Summer 2021
  • Exercises on School Mathematics: Applied Mathematics
    University of Vienna, 1 hour
• Summer 2020
  • Introduction to Mathematical Methodology (student tutorials)
    University of Vienna, 4 hours
• Winter 2019
  • Introduction to Mathematical Methodology (student tutorials)
    University of Vienna, 4 hours
  • Mathematics exercises (Food Science and Biotechnology)
    University of Natural Resources and Life Sciences Vienna, 2 hours
  • Mathematics I (Forestry and Wood Engineering)
    University of Natural Resources and Life Sciences Vienna, 2 hours
• Summer 2019
  • Tutorials for Introductory Phase
    University of Vienna, 4 hours

All courses that I have taught at the University of Vienna are listed here.