Klaus Kroencke
Fachbereich Mathematik
Bereich AD
Bundesstraße 55 (Geomatikum)
20146 Hamburg

Raum 314
Tel.: +49 40 428385183
Fax: +49 40 428385190
EMail:
klaus.kroencke (at) unihamburg.de

Sprechstunden im SoSe 2018:
Di 1011 Uhr und nach Vereinbarung per EMail
I am an assistant professor in mathematics at the University of
Hamburg. Before I moved to Hamburg, I was a postdoc at the University
of Regensburg. I obtained my PhD degree in Mathematics at the
University of Potsdam under the supervision of Prof. Dr. Christian
Bär, funded by the Max Planck Institute for Gravitational
Physics. Previously, I did my diploma studies in Mathematics at the
University of Vienna.
My research interests revolve around differential geometry, global
analysis, partial differential equations and general relativity. More
precisely, I am interested in special geometric structures (Einstein
metrics and Ricci solitons), their stability and the structure of
their moduli spaces. Moreover, I am interested in geometric flows (in
particular Ricci flow) and nonlinear stability problems in general
relativity.

Holonomy rigidity for Ricciflat metrics (with Bernd Ammann, Hartmut Weiß and Frederik Witt) [arXiv]
To appear in: Math. Z.

Stable fixed points of the Einstein flow with positive cosmological constant (with David Fajman)
[arXiv]
To appear in: Comm. Anal. Geom.

Stability of Einstein metrics under Ricci flow
[arXiv]
To appear in: Comm. Anal. Geom.

Stability of sincones and coshcylinders [arXiv]
To appear in: Ann. Sc. Norm. Super. Pisa, Cl. Sci.

Ricci flow with metric torsion on closed surfaces (with Volker Branding)
[Journal, arXiv]
In: J. Geom. Anal. 27 (2017) no. 3, 20982117

Stable and unstable Einstein warped products [Journal, arXiv]
In: Trans. Amer. Math. Soc. 369 (2017) no. 9, 65376563

The EinsteinΛ flow on product manifolds (with David Fajman)
[Journal, arXiv]
In: Class. Quant. Grav. 33 (2016) no. 23, 235018

Rigidity and infinitesimal deformability of Ricci solitons
[Journal, arXiv]
In: J. Geom. Anal. 26 (2016) no. 3, 17951807

Stability and instability of Ricci solitons [Journal, arXiv]
In: Calc. Var. Partial Differ. Equ. 53 (2015) no. 12,265287

On the stability of Einstein manifolds
[Journal, arXiv]
In: Ann. Global Anal. Geom. 47 (2015) no. 12, 8198

On infinitesimal Einstein deformations
[Journal, arXiv]
In: Differ. Geom. Appl. 38 (2015) 4157
Preprints:

Stable cosmological KaluzaKlein Spacetimes (with Volker Branding and David Fajman)
[arXiv]

Stability of Ricci de Turck flow on Singular Spaces (with Boris Vertman)
[arXiv]

Global existence of wave maps and some generalizations on expanding spacetimes (with Volker Branding)
[arXiv]

Stability of ALE Ricciflat manifolds under Ricci flow (with Alix Deruelle)
[arXiv]
Conference proceedings:

Stability of ALE Ricciflat manifolds under Ricci flow [MFO]
To appear in: Oberwolfach Reports

Variational Stability and Rigidity of compact Einstein Manifolds [Springerlink]
F. Finster et al. (eds.) Quantum Mathematical Physics. A Bridge between Mathematics and Physics, 497513, Springer, 2016

Stability and instability of Ricci solitons [MFO]
In: Oberwolfach Reports 11 (2014) no. 3, 20172019
 Stability of Einstein Manifolds [OPUS]
Doctoral thesis, University of Potsdam, 2013
 Comparison theorems in Riemannian geometry [Etheses]
Diploma thesis, University of Vienna, 2010

Field equations on Lorentzian spacetimes
Workshop, Hamburg, March 1923, 2018
Organizers: Vicente Cortés, Sari Ghanem and Klaus Kröncke

Geometric evolution equations
Winter school, Konstanz, February 59, 2018
Organizers: Klaus Kröncke, Miles Simon, Oliver Schnürer and Boris Vertman

8th Northern German Differential Geometry Day
Hannover, June 30, 2017
Organizers: Roger Bielawski and Knut Smoczyk
(Hannover), Vicente Cortés and Klaus Kröncke (Hamburg), Jens Heber and Hartmut Weiß (Kiel)

Geometric Flows and the Geometry of Spacetime
Summer School and Workshop, Hamburg, September 1923, 2016
Organizers: Vicente Cortés, Klaus Kröncke and Jan Louis

7th Northern German Differential Geometry Day
Hamburg, June 10, 2016
Organizers: Roger Bielawski and Knut Smoczyk
(Hannover), Vicente Cortés and Klaus Kröncke (Hamburg), Jens Heber and Hartmut Weiß (Kiel)

Stability and instability of Einstein manifolds with prescribed asymptotic geometry
Project within the framework of the SPP 2026 Geometry at infinity
Selected seminar and conference talks:
 April 23, 2018, Differential Geometry Seminar, University of Münster
 Mar 5, 2018, Workshop on Geometric Evolution Equations, University of Regensburg
 Mar 2, 2018, Seminar on Global Analysis, University of Regensburg
 Jan 25, 2018, Seminar on Differential Geometry, University of Potsdam
 Dec 22, 2017, 6th Christmas colloquium, Technical University of Vienna
 Nov 24, 2017, Seminar on Nonlinear Analysis, University of Vienna
 Oct 913, 2017, Summer school on Geometric Analysis on Noncompact Manifolds, University of Copenhagen
 Oct 2, 2017, Geometry and Topology Seminar, McMaster University
 Sep 29, 2017, Seminar on Geometric Analysis, Rutgers University
 Sep 28, 2017, Seminar on Geometric Analysis, City University of New York
 Sep 26, 2017, Seminar on Geometric Analysis, University of Maryland
 Sep 14, 2017, Postdoctoral Seminar, Fields Institute, Toronto
 Sep 6, 2017, Geometric Analysis Colloquium, Fields Institute, Toronto
 August 9, 2017, Workshop on Positive Scalar Curvature, Oberwolfach
 May 16, 2017, Seminar on Analysis and Theoretical Physics, University of Hannover
 April 20, 2017, Analysis Seminar, University of Oldenburg
 February 16, 2017, 7th European Relativity Seminar, University of Bremen
 February 9, 2017, Colloquium of the Graduiertenkolleg, University of Regensburg
 December 9, 2016, Seminar on PDE and Dynamical Systems, University of Hamburg
 July 7, 2016, Seminar on Differential Geometry and Analysis, University of Hannover
 June 23, 2016, Geometric Analysis Seminar, AEI Potsdam
 June 10, 2016, 7th Northern German Differential Geometry Day, University of Hamburg
 February 9, 2016, Seminar on Riemannian Geometry, MSRI Berkeley
 December 21, 2015, Seminar on Special Holonomy, University of Regensburg
 November 24, 2015, Colloquium in Pure Mathematics, University of Hamburg
 September 30, 2015, Seminar on Dirac Operators, University ParisSud
 September 22, 2015, Jahrestagung der DMV, Hamburg
 August 19, 2015, Geometric Analysis Seminar, MPIM Bonn
 May 19, 2015, Geometry Seminar, University of Munich
 February 27, 2015, 5th European Relativity Seminar, Hungarian Academy of Sciences, Budapest
 January 23, 2015, BrusselsLondon geometry seminar, University of Brussels
 January 14, 2015, Geometry Seminar, University of Kiel
 November 25, 2014, Geometry and Topology Seminar, University of Stuttgart
 August 7, 2014, Workshop on Positive Scalar Curvature, Oberwolfach
 May 28, 2014, Geometry and Physics Seminar, University of Vienna
 May 13, 2014, Workshop on Kähler Geometry and Geometric Analysis, University College Cork
 March 27, 2014, Workshop on Geometric and Singular Analysis, University of Potsdam
 February 28, 2014, 4th European Relativity Seminar, ESI Vienna
 December 5, 2013, Topics in Geometric Analysis Seminar, AEI Potsdam
 November 6, 2013, Global Analysis and Geometry Seminar, University of Regensburg
 November 4, 2013, Differential Geometry Seminar, University of Münster
 April 7, 2013, Global Analysis Seminar, University of Bonn
 March 8, 2013, Gravitational Physics Seminar, University of Vienna
 January 28, 2013, Geometric Analysis Seminar, AEI Potsdam
