Stefan Czimek

Associate Professor of Mathematics at Leipzig University.

firstname.lastname at uni-leipzig.de

Office 332
Mathematisches Institut
Augustusplatz 10
04109 Leipzig, Deutschland

I did postdocs at the Fields Institute, the University of Toronto and
ICERM at Brown University. I defended my PhD at the LJLL (Paris 6)
under the supervision of Jérémie Szeftel.

News

I will give a talk at the workshop Mathematical Relativity: Past, Present, Future which takes places at the ESI Vienna upon the occasion of Yvonne Choquet-Bruhat's 100th birthday.
I am a co-organizer of the Leipzig General Relativity seminar.
I was a co-organizer of the workshop Women in Mathematical Relativity which took place online on April 14, 2023. Find here the workshop homepage and the poster.

Research

In my research I use tools from analysis, PDE theory and differential geometry to study fundamental problems of general relativity.
More specifically, I have been working on the following topics:

Construction and analysis of spacelike initial data for the Einstein equations.
Control of solutions to the null structure equations, with sharp estimates in low-regularity geometric function spaces.
Solving the Einstein equations in low-regularity (continuation results, blow-up criteria).
Gluing problems for characteristic and spacelike initial data.

Publications and preprints

(with Rodnianski) Obstruction-free gluing for the Einstein equations. arXiv:2210.09663.
(with Aretakis and Rodnianski) Characteristic gluing to the Kerr family and application to spacelike gluing. Comm. Math. Phys. 403, 275-327 (2023).
(with Aretakis and Rodnianski) The characteristic gluing problem for the Einstein vacuum equations. Linear and non-linear analysis. arXiv:2107.02449, to appear in Ann. Henri Poincaré.
(with Aretakis and Rodnianski) The characteristic gluing problem for the Einstein equations and applications. arXiv:2107.02441.
(with Graf) The spacelike-characteristic Cauchy problem of general relativity in low regularity. Ann. PDE 8, 22 (2022).
(with Graf) The canonical foliation on null hypersurfaces in low regularity. Ann. PDE 8, 23 (2022).
The localised bounded $L^2$-curvature theorem. Comm. Math. Phys. 372, 71-90 (2019).
Boundary harmonic coordinates on manifolds with boundary in low regularity. Comm. Math. Phys. 371, 1131-1177 (2019).
An extension procedure for the constraint equations. Ann. PDE 4, 2 (2018).

Theses

The Cauchy problem in general relativity, Ph.D. thesis, UPMC (Paris 6), 2017, 259 pages.
On the static metric extension problem (here), Master’s thesis at ETH Zurich, 2014, 21 pages.

Short CV

2022-present: Associate Professor, Mathematisches Institut, Leipzig University
2020-2022: Institute Postdoc, ICERM, Brown University
2018-2020: Postdoc, University of Toronto
2017: Postdoctoral Fellow, Fields Institute
2017: Ph.D. in Mathematics at UPMC (Paris 6).
2014: M.Sc. Physics ETH, ETH Zurich (funded by ESOP scholarship).
2012: B.Sc. Physics ETH, ETH Zurich.

Invited talks at seminars

06/2023 General Relativity seminar, University of Munster
05/2023 Analysis seminar, ETH Zurich
01/2023 General Relativity seminar, University of Vienna
11/2022 Analysis seminar, Oxford University
11/2022 London PDE Seminar, Imperial College London
11/2022 Analysis seminar, University of Edinburgh
03/2022 Analysis/probability seminar, Max-Planck-Institute Leipzig
12/2021 Colloquium, JoMaReC
11/2021 Colloquium, Black Hole Initiative, Harvard University
11/2021 Colloquium, Gravity Initiative, Princeton University
10/2021 PDE and Differential Geometry seminar, UConn
10/2021 GR and Geometric Analysis seminar, Columbia University
10/2021 ICERM seminar, Brown University
08/2021 Relativity Seminar, University of Vienna
06/2021 Analysis Seminar, Caltech
06/2021 Summer Meeting, Canadian Mathematical Society
03/2021 Colloquium, University of Leipzig
03/2021 Research Symposium, UC Irvine
03/2021 AMS Eastern Sectional Meeting
03/2021 PDE seminar, Vanderbilt University
11/2020 General Relativity Webinar, Princeton University
10/2020 Colloquium, University Freiburg im Breisgau
06/2020 Canadian Mathematical Society, online (cancelled)
02/2020 Colloquium, University Konstanz
02/2019 Geometric analysis seminar, Fields Institute
11/2017 Analysis and Applied Math seminar, University of Toronto
02/2017 Pure Analysis and PDE seminar, Imperial College
02/2017 Geometry seminar, LMPT, Tours
12/2016 Mathematical Physics seminar, Institut Fourier, Grenoble
10/2016 General relativity seminar, Paris 6

Invited talks at workshops, conferences, and schools

07/2023 5h mini-course On null gluing, Domoschool 2023, Domodossola, Italy (see here)
07/2023 Main conference of Thematic Programme Spectral Theory and Mathematical Relativity, ESI Vienna
03/2023 8h mini-course On characteristic gluing, International junior scientist workshop: Mathematical GR, Tubingen
02/2023 3h Ringvorlesung General Relativity, MPI MIS Leipzig
03/2022 6h mini-course On characteristic gluing, Harvard University
08/2021 Mathematical Aspects of GR, MFO, Oberwolfach
05/2018 Initial data in general relativity, Fairbanks, Alaska

Online talks

07/2023 Link Main conference of Thematic Programme Spectral Theory and Mathematical Relativity, ESI Vienna
11/2021 Link Colloquium, Black Hole Initiative, Harvard University