8/11/23 Mathematisches Kolloquium der Universitäten Marburg und Giessen, Giessen, Multistability in biochemical reaction networks.
11/9/23 Workshop on mathematical aspects of immunobiology, Blagoevgrad, Bulgaria, Monotonicity of the response function for the initiation of T cell activation.
5/7/23 Tag der offenen Tür, JGU Mainz, Macht Mathematik gesund?
16/9/22 Jahrestagung der DMV, FU Berlin, Phenomenology of an in-host model for hepatitis C.
12/11/21 Applied Mathematics Seminar, St. Andrews, Scotland, online. Regulation of enzymatic activity of Lck by autophosphorylation.
16/6/21 SMB Annual Meeting, online, Global convergence to steady states in a model for the in-host dynamics of hepatitis C.
20/4/21 Oberseminar Nonlinear Dynamics (FU Berlin/WIAS), online. Bogdanov-Takens bifurcations and the regulation of enzymatic activity by autophosphorylation.
8/4/21 Online seminar Mathematics of Reaction Networks (Torino/Copenhagen/Wien), Using Bogdanov-Takens bifurcations to study existence and stability of periodic solutions.
17/8/20 SMB Annual Meeting, online, Autophosphorylation as a source of multistability
26/9/19, Jahrestagung der DMV, Karlsruhe, A proof of unlimited multistability for phosphorylation cycles
9/9/19 Tagung, Mathematical Biology on the Mediterranean, Samos, Griechenland, Mathematical models for immune checkpoint therapy of cancer
23/7/19, Tagung, SMB annual conference, Montreal, Kanada, A proof of unlimited multistability for phosphorylation cycles
12/3/19, KTH Stockholm, Schweden, Using mathematics to improve understanding of T cell activation
30/1/19, Tag der offenen Tür, JGU Mainz, Macht Mathematik gesund?
10/9/18 RWTH Aachen, Periodic solutions of the MAPK cascade
8/8/18 SIAM Life Science Conference, Minneapolis, USA, Dynamics of the Selkov model of glycolysis
3/8/18 Northeastern University 2018 Systems Biology Day, Boston, USA, Models of T cell activation
2/8/18 Harvard Medical School, Boston, USA, Models for the initiation of T cell activation
23/7/18 Tagung, ECMTB 2018, Lissabon, Portugal, Bounded and unbounded oscillations in the Selkov model of glycolysis
5/7/18 SYMBIONT Kick-off Meeting, Bonn, Examples of how mathematics can be used to identify qualitative features of solutions of reaction networks
2/3/18 Tagung, The Mathematics of Mechanobiology and Cell Signalling, Oberwolfach. Initiation of T cell signalling.
30/1/18, Tag der offenen Tür, JGU Mainz, Macht Mathematik gesund?
28/7/17 Universität Heidelberg, Models for the initiation of T cell activation
21/6/17 Tagung, Reaction Networks and Population Dynamics, Oberwolfach, Mathematical models for T cell activation
14/6/17, Mainzer Mathe Tag, Mathematik und das Immunsystem
8/6/17 Tagung, Mathematical Analysis of Biological Interaction Networks, Banff International Research Station, Kanada, Multiple steady states in models for the Calvin cycle of photosynthesis
13/2/17, Winter Excursion, Elite Master Course TMP, Bayrischzell, Relations between mathematics and its applications to biology and medicine
26/7/16, Tagung, Patterns of Dynamics, Berlin, Dynamics of the Calvin cycle
15/7/16 Tagung, ECMTB 2016, Nottingham, UK, Energy distribution and endothermy in dinosaur and modern birds
10/6/16 Theoretical Biology Laboratory, RIKEN, Wako, Japan, Mathematical models for T-cell activation
7/6/16 Theoretical Biology Laboratory, RIKEN, Wako, Japan, Dynamics of the Calvin cycle
2/6/16 FU Berlin, Dynamical systems arising from the Calvin cycle
11/5/16 Niels Bohr Institute, Kopenhagen, Dynamics of the Calvin cycle
3/10/15 Central Fall Sectional Meeting, American Mathematical Society, Chicago, USA, Overload breakdown in models for photosynthesis
29/9/15 Kolloquium, University of West Virginia, Sustained oscillations in phosphorylation cascades.
3/7/15 Tagung, Mathematical Trends in Reaction Network Theory, Kopenhagen, Dynamics of phosphorylation systems
4/3/15 Tagung, Flowers and Friends in Frankfurt, Qualitative properties of dynamical systems arising in biology.
4/2/15 Hausdorff Colloquium, Universität Bonn, The MAPK cascade and the mathematics of signalling networks in cell biology.
3/2/15 Tag der offenen Tür, JGU Mainz, Als Hasen Luchse fraßen
1/10/14 International BIOMS Workshop Modelling Cellular Systems, BioQuant, Heidelberg, Dynamical features of the MAP kinase cascade: phenomenology and functional meaning
5/8/14 SIAM conference on the life sciences, Charlotte, USA, Bistability in the dual futile cyle and periodic solutions of the MAPK cascade
8/7/14 10th AIMS International Conference on Dynamical Systems, Differential Equations and Applications, Madrid, Dynamical properties of the MAP kinase cascade
27/2/14 Max Planck Institut für Dynamik komplexer technischer Systeme, Magdeburg, Dynamische Eigenschaften der MAPK-Kaskade
30/1/14 Tag der offenen Tür, JGU Mainz, Als Hasen Luchse fraßen
8/11/13 Mainzer Abend der Mathematiker plus Freunde, JGU Mainz, Als Hasen Luchse fraßen: Mathematik und Wirklichkeit
7/11/13 Theoriekolloquium, Institut für Physik, JGU Mainz, Die Verwendung struktureller Eigenschaften bei der Analyse mathematischer Modelle in der Molekularbiologie
6/11/13 Kolloquium, Universität Würzburg, Analysis of some dynamical systems arising in molecular biology
26/9/13 Jahrestagung der ÖMG und der DMV, Innsbruck, Dynamical properties of models for the Calvin cycle of photosynthesis.
28/6/13 Kolloquium, Forschungsschwerpunkt Mathematische Modellierung, Universität Bielefeld, Chemical reaction network theory and immunological signalling pathways.
14/6/13 Forschungsseminar Darmstadt-Mainz. Ein Modell für die Photosynthese und Systeme mit verschiedenen Zeitskalen.
23/5/13 Antrittsvorlesung, JGU Mainz. Mathematische Analyse dynamischer Systeme aus der Zellbiologie.
15/5/13 Institut für Molekulare Biologie, Mainz. NFAT and T cell activation.
8/1/13 Kolloquium SFB 647, Max-Planck-Institut für Gravitationsphysik. Introduction to the BKL picture.
30/11/12 Berlin Mathematical School Friday Colloquium. Spacetime singularities and heteroclinic chains.
19/11/12 Karlstad University. Illustrative examples of the uses of mathematical modelling.
1/11/12 FU Berlin. Relaxation oscillation in the MAP kinase cascade.
29/10/12 Universität Münster. Oscillatory singularities in solutions of the Einstein equations.
3-7/9/12 Spanish Relativity Meeting in Portugal, Guimarães. Vortrag: Construction of oscillatory singularities.
30/7-3/8/12 Tagung, Mathematical Aspects of General Relativity, Oberwolfach, Vortrag: Stability of heteroclinic cycles and construction of oscillatory singularities.
25-28/7/12 Tagung, Society for Mathematical Biology Annual Conference, Knoxville, USA. Vortrag: Mathematics of the NFAT signalling pathway.
21/5/12 KTH Stockholm. Future stability for the Einstein-matter equations and the cosmic no hair theorem.
11/5/12 FU Berlin. Signalling pathways in T cells and chemical reaction network theory.
9/2/12 Université de Paris VI. Singularity formation in solutions of the Einstein-Vlasov system.
20/1/12 Universität Erlangen. Globale Dynamik von Lösungen des Einstein-Vlasov-Systems.
15/12/11 FU Berlin. Multiple steady states in a dynamical system arising in immunology.
4/11/11 Universität Wien. Analyse eines mathematischen Modells aus der Immunologie.
3/11/11 Universität Wien. Late-time behaviour of spatially homogeneous solutions of the Einstein equations.
25/9/11 Tagung, Vlasov models in kinetic theory, Brown University, USA. Vortrag, A self-similar solution of the Einstein-Vlasov system.
22-24/6/11 Tagung, Kinetic theory and related fields, Pohang University, Korea. Vortrag: Late-time behaviour of spatially homogeneous solutions of the Einstein-Vlasov system.
20/6/11 Seoul National University, Korea. A self-similar solution of the Einstein-Vlasov system.
17/6/11 Seoul National University, Korea. Introduction to the Einstein-Vlasov system.
18/5/11 Research Center ImmunoSciences, Charite, Berlin. Analysis of a model for interactions between T cells and macrophages.
9/2/11 Universität Heidelberg. Dynamik stoßfreier Materie.
28/1/11 Universität Mainz. Dynamik stoßfreier Materie.
27/1/11 Erwin-Schrödinger-Institut, Wien. Self-similar collapse of collisionless matter.
22/12/10 RWTH Aachen. Dynamik stoßfreier Materie.
4/12/10 Swedish GR meeting, Karlstad. Self-similar collapse of collisionless matter.
21-25/6/10 Tagung, Geometric Analysis and General Relativity, Banff, Kanada. Vortrag: Higher dimensional cosmological models.
5-9/4/10, Tagung, PDEs, Relativity and Nonlinear Waves, Granada, Spanien. Vortrag: Some wave maps related to the Einstein equations.
16/3/10 Universität Bonn. Anwendungen von hyperbolischen Gleichungen in der Kosmologie.
3/3/10 Kompaktkurs Relativitätstheorie, Graduiertenkolleg des SFB 647, Berlin. Open problems in general relativity.
18-29/1/10 Forschungsprogramm, 'Quantitative Studies of Nonlinear Wave Phenomena', Erwin-Schrödinger-Institut, Wien. Vortrag: Relations between Gowdy and Bianchi spacetimes.
18/12/09 FU Berlin. Introduction to black holes.
4-6/11/09 Tagung, Mathematical methods in general relativity and quantum field theories, Paris. Vortrag: Relations between Gowdy and Bianchi spacetimes
20/10/09 University of Oxford. Relations between Gowdy and Bianchi spacetimes.
14-18/9/09 Tagung, Hot Topics: Black Holes in Relativity, MSRI, Berkeley. Vortrag: The characteristic initial value problem in general relativity.
20-22/7/09 Tagung, Lorentzian Geometry, Greifswald. Vortrag: The Einstein-Maxwell equations and the complex hyperbolic plane.
18-19/6/09 Tagung, Mathematical Relativity in Lisbon. Vortrag: Dynamics of linearized cosmological perturbations.
12/6/09 Universität Jena. Loss of regularity in solutions of the Einstein-Euler system.
30/4/09 FU Berlin. Introduction to the Gowdy equations.
17/4/09 FU Berlin. Localization at the singularity in Bianchi models.
2/4/09 University of Edinburgh. Cosmic censorship: an introduction and status report
9/3/09 University of Cambridge. Dynamics of linearized cosmological perturbations.
26/11/08 MPIMIS Leipzig. Analysis of large scale structure formation.
15/10/08 Linköping University. Loss of regularity in solutions of the Einstein-Euler system.
9/10/08 Mittag-Leffler Institute, Stockholm. Cosmological weak null singularities
25-29/8/08 Tagung, Geometry and Analysis, KTH Stockholm. Vortrag: Cosmological perturbation theory.
16-19/6/08 Tagung, Hyperbolic Equations in Relativity. University of Bordeaux. Vortrag: Loss of regularity in solutions of the Einstein-Euler system.
7-17/4/08 Tagung, Mathematical aspects of general relativity. Niels Bohr Institute, Kopenhagen. Vortrag: The interface between mathematics and astrophysics in the study of cosmic acceleration.
22/4/08 HU Berlin. Spatially homogeneous solutions of the Einstein equations.
13/3/08 Jagiellonian University, Krakow. Strong cosmic censorship from the point of view of Lorentzian geometry.
12/3/08 Jagiellonian University, Krakow. Dynamics of accelerated cosmological expansion.
7/11/07 Universidad Complutense, Madrid. Dynamics of scalar field models in cosmology.
1/11/07 FU Berlin. Dynamical systems arising from Bianchi models.
16-20/7/07 6th International Congress on Industrial and Applied Mathematics, Zürich. Vortrag: Asymptotics of expanding cosmological models.
7/6/07 FU Berlin. Dynamics of Bianchi models.
4/4/07 Université de Paris VI. Stabilité de l'espace de de Sitter.
2/4/07 Universite de Paris VI. Structure globale des espace-temps avec matière cinétique.
24/1/07 MPI für Mathematik in den Naturwissenschaften, Leipzig. Some ODE and PDE problems arising in cosmology.
14/11/06 Kolloquium des SFB 647, HU Berlin. Exotic matter models in cosmology.
6-10/11/06 Workshop on Global Problems in Relativity, Universidad de Córdoba, Argentinien. Vortrag: Late-time oscillatory behaviour in cosmological spacetimes.
9-11/10/06 Conference on Multiscale Models, TU München. Vortrag: Theoretical approaches to gravitational radiation.
22-30/8/06 International Congress of Mathematicians, Madrid. Vortrag: Models for accelerated cosmological expansion.
25/5/06 Kings College London, UK. Mathematics of accelerated cosmological expansion.
27/4/06 Universität Göttingen, Solutions of the Einstein equations with accelerated expansion.
10/3/06 University of Cambridge, UK. Dynamics of $k$-essence.
13/1/06 Oberwolfach. Accelerated cosmological expansion and $k$-essence.
12/12/05 Universität Duisburg-Essen. Fuchs'sche Systeme und ihre Anwendungen auf die Allgemeine Relativitätstheorie.
22-26/8/05 Tagung, Global general relativity, Isaac Newton Institute, Cambridge, UK. Vortrag: Asymptotic expansions for cosmological solutions of the Einstein equations.
18/8/05 Université de Yaounde I, Kamerun. Black holes and trapped surfaces in solutions of the Einstein-Vlasov system.
16/8/05 Université de Yaounde I, Kamerun. New results for Vlasov systems.
18-21/7/05 Tagung, Asymptotic Analysis and Singularity, Sendai, Japan. Plenarvortrag: Solutions of the Einstein equations with accelerated expansion.
29/6/05 Kolloquium des SFB 647, FU Berlin. Cosmic acceleration and dark energy.
23/6/05 Kolloquium, FU Berlin. Mathematik der kosmischen Beschleunigung.
9/6/05 Kolloquium, Universität Bayreuth. Die Allgemeine Relativitätstheorie und die kosmische Beschleunigung.
18/1/05 ETH Zürich, Schweiz. Mathematics of cosmic acceleration.
22/11/04 Kolloquium, Chalmers University of Technology, Göteborg, Schweden. Mathematics of cosmic acceleration.
18/11/04 Chalmers University of Technology, Göteborg, Schweden, The plane symmetric Einstein-Vlasov system.
4/10/04 IMPRS seminar, Beetzsee. Vortrag: Global asymptotics of solutions of the Einstein equations.
19/7/04 GR17, Dublin, Irland. Vortrag: Mathematical results on cosmological models with accelerated expansion.
14/7/04 Erwin-Schrödinger-Institut, Wien, Österreich. Analogies between spacetime singularities and inflationary late-time asymptotics.
12/7/04 HYKE-Tagung, Wien, Österreich. Vortrag: Solutions of the Einstein equations with accelerated expansion.
9/7/04 HYKE-Tagung, Wien, Österreich. Vortrag: Introduction to the Einstein equations.
8/6/04 Two-city geometry seminar, MPI für Mathematik in den Naturwissenschaften, Leipzig. Dynamics of cosmological models with accelerated expansion.
24/4/04 Weierstrass-Institut, Berlin. Das Einstein-Vlasov-System.
8/3/04 IHES, Frankreich. Accelerated expansion in cosmology.
4/3/04 Bad Honnef. Mathematical properties of cosmological models with accelerated expansion.
05/01/04 Tagung Miami Waves, Miami, USA. Vortrag: Asymptotics of solutions of the Einstein equations with positive cosmological constant.
5/12/03 Université de Tours, Frankreich. Asymptotics of solutions of the Einstein equations with positive cosmological constant.
17/9/03 Jahrestagung, Deutsche Mathematiker-Vereinigung, Rostock. Vortrag: Simplification of the Einstein equations due to a cosmological
constant.
23/6/03 Isaac Newton Institute, Cambridge, UK. Late-time asymptotics of expanding cosmological models.
23/5/03 Universität Freiburg. A hyperbolic system modelling the dynamics of spacetime geometry.
12/11/02 FU Berlin. Monotone and oscillatory behaviour near spacetime singularities.
21/10/02 Astrophysikalisches Institut, Potsdam. Gravity, geometry, analysis.
29/7/02, 30/7/02, 1/8/02 Vortragsreihe, Cargèse, Korsika, Frankreich. The Einstein-Vlasov system.
24/6/02 IMA, Minneapolis, USA. The Cauchy Problem for the Einstein equations.
21/5/02 Stanford, USA. The Einstein-Vlasov system.
7/5/02 Karlstad, Schweden, Mathematics of self-gravitating collisionless matter.
15/2/02 Kolloquium, University of Waterloo, Kanada. The Einstein equations from a PDE perspective.
14/2/02 University of Waterloo, Kanada. Spatially homogeneous cosmological models with collisionless matter.
8/1/02 ETH Zürich, Schweiz. When do the Einstein equations lead to simple singularities?
13/12/01 Erwin-Schrödinger-Institut, Wien, Österreich. The non-relativistic limit of the Einstein-Vlasov system.
20/11/01 Universität Essen. Ein System von hyperbolischen Gleichungen als Modell fuer Raumzeit-Singularitäten.
21/7/01 GR16-Konferenz, Durban, Südafrika. Plenarvortrag: Applications of the theory of evolution equations to general relativity.
3/7/01 Erwin-Schrödinger-Institut, Wien, Österreich. Fuchsian equations and spacetime singularities.
17-18/6/01 Tagung ueber kinetische Theorie, Anogia, Kreta, Griechenland. Zwei Vorträge: The Einstein-Vlasov system.
21/5/01 Oberwolfach. Asymptotic decoupling of solutions of the Einstein equations.
29/11/00 Technische Universität München. Analysis of a continuum mechanics model with radiation damping,
19/10/00 MPI für Mathematik in den Naturwissenschaften, Leipzig. Structure of singularities in general solutions of the Einstein equations.
13/10/00 Université Libre de Bruxelles, Belgien. New approaches to singularities in general relativity.
24-25/8/00 Asia Pacific Centre for Theoretical Physics, Seoul, Korea. Zwei Vorträge: New developments in the study of spacetime singularities.
5-9/6/00 Tagung, Journées Equations aux Dérivees Partielles, Nantes, Frankreich. Vortrag: Blow-up for solutions of hyperbolic PDE and spacetime singularities.
31/05/00 Habilitationsvortrag, TU Berlin. Singuläre Lösungen hyperbolischer Systeme und ihre Bedeutung fuer die Gravitationstheorie.
2/3/00 Tagung, Eighth International Conference on Hyperbolic Problems. Theory, Numerics, Applications, Universität Magdeburg. Vortrag: The Einstein equations and hyperbolicity.
31/1/00 Universität Zürich, Schweiz. Structure of spacetime singularities in the presence of a scalar field.
20/1/00 University of California San Diego, USA. Singularity structure of solutions of the Einstein equations.
3 Wochen in 1/00. Forschungsaufenthalt, Institute for Theoretical Physics, Santa Barbara, USA. Vortrag: Hyperbolicity and numerical relativity.
5-11/11/99 Tagung, Nonlinear equations in many-particle systems, Oberwolfach. Vortrag: Survey of results on the Einstein-Vlasov system.
2/8/99 Tagung, Equadiff99, FU Berlin. Vortrag: Solutions of the Einstein equations with prescribed singularity structure.
2/7/99 Vortrag, Universität Potsdam. Vlasov systems: an overview.
4/6/99 Edinburgh Mathematical Society, Aberdeen, UK. Vortrag: Blow-up singularities of solutions of hyperbolic PDE and their significance for general relativity.
4 Wochen in 4/99. Forschungsaufenthalt, Institute for Theoretical Physics, Santa Barbara, USA. Vortrag: Quiescent cosmological singularities.
11/02/99 Université de Reims, Frankreich. Solutions globales du système d'Einstein-Vlasov.
07-11/09/98 Seminar über Mathematische Relativitästheorie, Bad Honnef. Vorträge (4 Stunden): The theorem of Christodoulou and Klainerman on the global nonlinear stability of Minkowski space.
30/3-4/4/98 International Seminar on Mathematical Cosmology, Universität Potsdam. Vortrag: Structure of singularities in inhomogeneous cosmological models.
10/3/98 Oxford Mathematical Institute, UK. Fuchsian equations and general relativity.
5/2/98 Universität Potsdam. Fuchsian equations in general relativity.
6/11/97 Universität Potsdam (im Rahmen des 'Tages der Naturwissenschaftlichen Fakultät'), Vortrag: Dynamische Eigenschaften der Gravitation.
2-8/3/97 Tagung, Quantenfeldtheorie und Wellenfronten, Oberwolfach. Vortrag: Meditation on spacetime singularities.
1-7/12/96 Tagung, Nonlinear Equations in Many-Particle Systems, Oberwolfach. Vortrag: Solutions of the Einstein-Vlasov system with U(1) x U(1) symmetry.
7/96 2nd International Congress of Nonlinear Analysts, Athen, Griechenland. Vortrag: Crushing singularities.
28/6/96 Tagung, Journées Relativistes, Ascona, Schweiz. Plenarvortrag: Constant mean curvature foliations in cosmological spacetimes.
8/5/96 TU Berlin. Globale symmetrische Lösungen des Einstein-Vlasov-Systems.
23/4/96 Royal Institute of Technology, Stockholm, Schweden. Global dynamics of solutions of the Einstein equations.
2 Wochen in 3/96 Forschungsaufenthalt, Banach Centre, Warschau, Polen. Vortrag: Topology of compact Cauchy horizons.
6-12/8/95 14th International Conference on General Relativity and Gravitation, Florenz, Italien. Plenarvortrag: Solutions of the Einstein equations with matter.
6/4/95 Université de Bordeaux, Frankreich. Solutions cosmologiques globales du système d'Euler-Poisson.
24/3/95 Frühjahrstagung der Deutschen Physikalischen Gesellschaft, Berlin. Hauptvortrag: Die Natur kosmologischer Singularitaeten.
4/11/94 Observatoire de Meudon, Paris, Frankreich. Reliability of post-Newtonian approximations.
11/10/94 Université de Paris VI, Frankreich. Cosmologie newtonienne.
1-31/7/94 Forschungsaufenthalt, Erwin-Schrödinger-Institut, Wien, Österreich. Vortrag: Crushing singularities in spacetimes with spherical and plane symmetry.
13-17/9/93 Tagung, Canonical Gravity: From Classical to Quantum, Bad Honnef. Vortrag: Adjointness relations as a criterion for choosing an inner product.
2 Wochen in 6/93 Forschungsaufenthalt, Ecole Polytechnique, Palaiseau, Frankreich. Vortrag: La limite newtonienne des équations d'Einstein.
1-31/3/93 Forschungsaufenthalt, University of California at Santa Barbara, USA. Vortrag: Global existence theorems for the spherically symmetric Vlasov-Einstein system.
12/92 Princeton University, USA. The Newtonian limit of the Vlasov-Einstein system.
9/92 Syracuse University, USA. The Newtonian limit of the Vlasov-Einstein system.
28/6-4/7/92 13th International Conference on General Relativity and Gravitation, Córdoba, Argentinien. Vortrag: Global dynamics of solutions of the spherically symmetric Vlasov-Einstein system.
16-20/12/91 Workshop on Numerical Relativity, Southampton, UK. Vortrag: On the choice of matter model in general relativity.
10/91 University of Chicago, USA. The initial value problem for self-gravitating fluid bodies.
10/91 University of Michigan, USA. The initial value problem for self-gravitating fluid bodies.
9/91 Vortrag, University of Maryland, USA. The initial value problem for self-gravitating fluid bodies.
9/91 Vortrag, Princeton University, USA. The initial value problem for self-gravitating fluid bodies
30/7-9/8/91 Xth Congress on Mathematical Physics, Leipzig. Vortrag: The initial value problem for self-gravitating fluid bodies
11/90 Universiät Linköping, Schweden. Generic properties of spacetimes in general relativity.
11/90 Royal Institute of Technology, Stockholm, Schweden. The Cauchy problem for the Einstein-Euler equations.
6/90 Tagung, Nonlinear hyperbolic equations and field theory, Varenna, Italien. Vortrag: The characteristic initial value problem for the Einstein equations.
24/4/90 Tagung, Georgenthal, DDR. Vortrag: The characteristic initial value problem for the Einstein equations.
1-31/3/90 Forschungsaufenthalt, Institut des Hautes Etudes Scientifiques, Bures sur Yvette, Frankreich. Vortrag: The characteristic initial value problem for the Einstein equations.
9/89 Third Hungarian Relativity Workshop, Tihany, Ungarn. Vortrag: Stability in the characteristic initial value problem.
2-8/7/89 12th International Conference on General Relativity and Gravitation, Boulder, USA. Vortrag: The characteristic initial value problem for the Einstein equations.
13/12/88 Charles University, Prag, Tschechoslowakei. Global existence of solutions of the Robinson-Trautman equation.
8-13/8/88 5th Marcel Grossmann Meeting, Perth, Australien. Vortrag: The Robinson-Trautman equation and Lyapunov functions.
7/88 University of Sydney, Australien. Vortrag: Global existence of solutions of the Robinson-Trautman equation.
20-22/7/88 Conference on Mathematical Relativity, Canberra, Australien. Vortrag: Describing spacetimes by their curvature.