

1996  PhD in Mathematics, University of Bonn  1996  1997  Postdoc, Courant Institute, New York University, NY, USA  1997  2003  Research Assistant (C1), University of Bonn  2001  Guest scientist, Max Planck Institute for Mathematics in the Sciences, Leipzig  2002  Habilitation in Mathematics, University of Bonn  2003  2007  Professor (C4), HU Berlin  2007  2012  Professor in the Mathematical Institute and Tutorial Fellow of St Edmund Hall, University of Oxford, England, UK  Since 2012  Professor (W3), University of Bonn 


My research interests are in applied mathematics and include the analysis of problems with multiple scales, dynamics in highdimensional dynamical systems and universal scaling behaviour in models of mass aggregation and coarsening.
A focus of my earlier research was Ostwald ripening, a fundamental process in the aging of materials, where small solid particles immersed in a liquid interact to reduce their total surface energy. The classical LSW theory suggests a meanfield equation for the size distribution of particles and predicts universal longtime behaviour of solutions. I have been working on a clarification of the range of validity of the LSW model [10,11] as well as on the analysis of the longtime behaviour of its solutions. Surprisingly, it turned out that the latter is not universal as predicted by LSW, but rather depends sensitively on the initial data [12]. A central issue in Ostwald ripening and many other problems where particles interact through a field is the understanding of screening effects, which means that interactions between particles that are in principle longrange are screened by neighbouring particles [13]. Subsequently I investigated further meanfield type equations for various coarsening mechanisms [14,15,16] and recently obtained some new results for Smoluchowski's coagulation equation [1] for which, apart from some exactly solvable models, only few results had been available.
In many coarsening systems that are relevant in applications, such as grain growth in polycrystals for example, the particle statistics cannot be described by a meanfield equation. A future goal is to develop methods to characterize initial configurations that exhibit a universal scaling behaviour. First steps in this direction for a onedimensional toy model can be found in [6].
I am also interested in the reduction of highdimensional dynamical systems with small parameters to lowdimensional evolution equations. On example arises in the description of manyparticle storage systems. The corresponding mathematical problem involves nonlocal FokkerPlanck equations with multiple scales that can be reduced in certain regimes to rate independent systems that exhibit hysteresis [9].


Project in DFG Research Center MATHEON on “Precipitation in crystalline solids”
2004  2008
DFG Research Group FOR 718 “Analysis and Stochastics in Complex Physical Systems”
Member, 2005  2007
DFG Graduate School on “Analysis, Numerics and Optimization of Multiphase Problems”
Member, 2005  2008
International Joint Project, Royal Society and CNRS, “Kinetic models with mass transport and coalescence”
2010  2012
Project “Selfsimilarity in Smoluchowski's coagulation equation”
within Collaborative Research Center SFB 1060 “The Mathematics of Emergent Effects”, 2013  2020
Project “Screening effects in interacting particle systems”
within Collaborative Research Center SFB 1060 “The Mathematics of Emergent Effects”, 2017  2020
“Bonn International Graduate School of Mathematics”
Director, since 2017





• SIAM Multiscale Modeling and Simulation
• Kinetic and Related Models
• Research in Mathematical Sciences


2003  Richard von Mises Prize, GAMM  2011  Whitehead Prize, London Mathematical Society 


2009  Annual Meeting of GAMM, Gdansk, Poland  2011  Equadiff, Loughborough, England, UK  2013  SIAM, Mathematical Aspects of Materials Science, Philadelphia, PA, USA  2014  International Congress of Mathematicians, Seoul, South Korea  2015  Dynamics Days Europe, Exeter, England, UK 


Reiner Henseler (2007): “A Kinetic Model for Grain Growth”
Dirk Peschka (2008): “SelfSimilar Rupture of Thin Liquid Films with Slippage” (joint with Andreas Münch),
now Assistant, Weierstrass Institute, Berlin
SvenJoachim Kimmerle (2009): “Macroscopic Diffusion Models for Precipitation in Crystalline Gallium Arsenide  Modelling, Analysis and Simulation”,
now Substitute Professor (“Vertretungsprofessor”), Bundeswehr University Munich
Michael Helmers (2011): “Kinks in a model for twophase lipid bilayer membranes”
Sebastian Throm (2016): “Selfsimilar solutions with fat tails for Smoluchowski's coagulation equation”


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