I am an associate professor for mathematics at VU Amsterdam, and part of the research groups on analysis and dynamical systems as well as on geometry and topology. I am also member of the Center for Topology & Applications Amsterdam (CTA^2) as well as the Amsterdam Center for Dynamics and Computations (ACDC). 

In 2014 I received my habilitation from the University of Hamburg, and in 2022 I was one of three finalists for the university teaching award. From 2018 to 2023 I was chair of the program committee for the bachelor and the master program in Mathematics. I am chair of the jury for the KWG PhD prize 2025 (prize for best PhD thesis in Mathematics in the Netherlands). Together with G. Benedetti, U. Frauenfelder, B. Hanke, and F. Schlenk I am organizer of the conference "Symplectic geometry. A conference in honor of Kai Cieliebak" that is planned to take place in Augsburg, Germany from August 24th to 28th, 2026. 

In November 2024 I was awarded an M-1 grant of the Dutch Research Council (NWO) for my project "Floer theory for stochastic Hamiltonian systems, quantum theory, and imaginary time", worth 350,000 Euros for 4 years. In the prioritization list it reached first place out of 30 applications. 

In my research I use methods from analysis, geometry and topology, and probability theory in order to establish the existence of solutions of nonlinear differential equations. My current work centers around the generalization of the J-holomorphic curve methods of symplectic geometry from finite-dimensional deterministic Hamiltonian systems to infinite-dimensional and stochastic Hamiltonian systems. 

List of publications:

(24) Generalizing symplectic topology from 1 to 2 dimensions. (with R. Brilleslijper) Arxiv preprint 2412.16223, 2024. 

(23) From Euclidean field theory to hyperkähler Floer theory via regularized polysymplectic geometry. (with R. Brilleslijper) Communications in Contemporary Mathematics, 2024.

(22) Cuplength estimates for time-periodic measures of Hamiltonian systems with diffusion. Journal of Fixed Point Theory and Applications 26(3), pp. 1-17, 2024.

(21) Regularized polysymplectic geometry and first steps towards Floer theory for covariant field theories. (with R. Brilleslijper) Journal of Geometry and Physics 183, pp. 1-22, 2023.

(20) Cuplength estimates for periodic solutions of Hamiltonian particle-field systems. (with N. Lamoree) Journal of Fixed Point Theory and Applications 25(2), pp. 1-22, 2023.

(19) Time-periodic solutions of Hamiltonian PDEs using pseudo-holomorphic curves. (with N. Lamoree) Algebraic & Geometric Topology 23(1), pp. 461-508, 2023.

(18) Hamiltonian Floer Theory for Nonlinear Schrödinger Equations and the Small Divisor Problem. International Mathematics Research Notices 2022(16), pp. 12220-12252, 2022.

(17) Higher algebraic structures in Hamiltonian Floer theory. Advances in Geometry 20(2), pp. 179-215, 2020.

(16) Polyfolds: A First and Second Look. (with J. Fish, R. Golovko, K. Wehrheim) EMS Surveys in Mathematical Sciences. 3(2), pp. 131-208, 2016.

(15) Local symplectic field theory. International Journal of Mathematics 24(5), 2013

(14) Topological recursion relations in non-equivariant cylindrical contact homology. (with P. Rossi) Journal of Symplectic Geometry 11(3), pp. 405-448, 2013.

(13) Integrable systems as homological invariants for open symplectic manifolds. EMS Oberwolfach Report 23(9), pp. 1383-1385, 2012.

(12) String, dilaton and divisor equation in symplectic field theory. (with P. Rossi) International Mathematical Research Notices 2011(19), pp. 4384-4404, 2011.

(11) Gravitational descendants in symplectic field theory. Communications in Mathematical Physics 302(1), pp. 113-159, 2011. 

(10) Transversality problems in symplectic field theory and a new Fredholm theory. MPI MIS Preprint 13/2010, 2010. 

(09) Obstruction bundles over moduli spaces with boundary and the action filtration in symplectic field theory. Mathematische Zeitschrift 269(2), pp. 325-372, 2011.

(08) Contact homology of Hamiltonian mapping tori. Commentarii Mathematici Helvetici 85(2), pp. 203-241, 2010.

(07) Ellipsoidal Wavelet Representation of the Gravity Field. (with M. Schmidt) Ohio State University Report 487, 2008.

(06) On the Estimation of a Multi-Resolution Representation of the Gravity Field Based on Spherical Harmonics and Wavelets. (with M. Schmidt and C.K. Shum) Journal of Geodynamics 39, 2005.

(05) Multiresolution Representation of a Regional Geoid from Satellite and Terrestrial Gravity Data. (with M. Schmidt, J. Kusche, J.P. van Loon, C.K. Shum and S.C. Han) IAG Sym- posia 129, 2005.

(04) Towards the Estimation of a Multi-Resolution Representation of the Gravity Field Based on Spherical Wavelets. (with M. Schmidt and C.K. Shum) IAG Symposia 128, 2005.

(03) Gravity field determination using multiresolution techniques. (with M. Schmidt, C.K. Shum, S.C. Han) In Proc. Of the 2nd Int. GOCE User Workshop: GOCE, The Geoid and Oceanography, ESA SP-569, 2004.

(02) Effiziente Wavelet Filterung mit hoher Zeit-Frequenz-Auflösung. Publications of the German Geodetic Commission, number A 119, 2004.

(01) Wavelet Filtering with High Time-Frequency Resolution and Effective Numerical Implementation Applied on Polar Motion. (with M. Schmidt) Artificial Satellites 38(1), 2003.