Welcome
Welcome to my webpage. I am head of the Weierstrass group Energy-variational Methods for Innovative Materials at the Weierstrass Institute for Applied Analysis and Stochastics, Berlin.
My research mainly focuses on the theory of generalized solutions, their approximation, and optimal control. You can also find my ORCID profile here: 0000-0002-1677-6925.
Highlights
- In February 2026 the new Weierstrass Group "Energy-variational Methods for Innovative Materials" was initiated.
- Robert Lasarzik recently received his Habilitation at FU Berlin; the thesis can be found here.
- The preprint "Probabilistically Strong Solutions to Stochastic Euler Equations", together with Benjamin Gess, can now be found on arXiv.
- The preprint "Existence and selection of solutions in the energy-variational framework with applications in fluid dynamics", together with Thomas Eiter and Marcel Śliwiński, can be found on arXiv.
- Giulia Cavalleri started her PostDoc in March within the Excellence Cluster MATH+.
- Maximilian Reiter submitted his PhD Thesis and his defense is scheduled for May 12, 2026.
- Robert Lasarzik will organize a Minisymposium at the FBP Conference together with Elisabetta Rocca and Hao Wu on Phase Field Methods in Real-World Applications.
- On April 28, Marcel Śliwiński and Robert Lasarzik from our group together with Thomas Eiter from Group 1 defended our project proposal on "Analysis of energy-variational solutions for hyperbolic conservation laws" for the second funding period within the SPP 2410 CoScaRa at the Review Event in Mainz. This went extremely well and the project was recommended for funding by the reviewers.
- A new article by Robert Lasarzik, together with Elisabetta Rocca and Giulio Schimperna, is now available online: Weak solutions and weak-strong uniqueness for a Cahn-Hilliard type model with chemotaxis. In this work, we establish the existence of global-in-time weak solutions and weak-strong uniqueness for a Cahn-Hilliard-Keller-Segel model. As a somewhat surprising result, we achieve global existence on general domains, something that remains unknown for the classical Keller-Segel model.
Research Interests
- Generalized solutions to the Ericksen–Leslie model
- Measure-valued, dissipative, entropy solutions
- Weak-strong uniqueness of solutions
- Liquid crystal flow
- Relative energy approach
- Optimal control
- Induction hardening
- Convergence of discretization methods
- Energy-variational solutions
- Phase-field models
- Viscoelastic fluids
Publications
- Robert Lasarzik, Elisabetta Rocca, Giulio Schimperna:
Weak solutions and weak-strong uniqueness for a Cahn-Hilliard type model with chemotaxis
Preprint: arXiv:2604.18211, submitted 20 April 2026 - Thomas Eiter, Robert Lasarzik, Emil Wiedemann:
On the equivalence of generalized solution concepts for systems of hyperbolic conservations laws in fluid dynamics
Preprint: arXiv:2604.00957, submitted 1 April 2026 - Thomas Eiter, Jan Giesselmann, Robert Lasarzik, Philipp Öffner, Robert Sauerborn:
Convergence analysis for a finite-volume scheme for the Euler- and Navier-Stokes-Korteweg system via energy-variational solutions
Preprint: arXiv:2603.29880, submitted 31 March 2026 - Benjamin Gess, Robert Lasarzik:
Probabilistically Strong Solutions to Stochastic Euler Equations
Preprint: arXiv:2601.22073, submitted 29 January 2026 - Thomas Eiter, Robert Lasarzik, Marcel Śliwiński:
Existence and selection of solutions in the energy-variational framework with applications in fluid dynamics
Preprint: arXiv:2601.20455, submitted 28 January 2026 - Fan Cheng, Robert Lasarzik, Marita Thomas:
Energy-variational solutions for geodynamical two-phase flows -- From logarithmic to double-obstacle potentials by variational convergence
Preprint: arXiv:2601.08625, submitted 13 January 2026 - Fan Cheng, Robert Lasarzik, Marita Thomas:
Analysis of a Cahn--Hilliard model for viscoelastoplastic two-phase flows
Preprint: arXiv:2509.25508, submitted 29 September 2025 - Robert Lasarzik:
Energy-variational structure in evolution equations
Preprint: arXiv:2503.11438, submitted 14 March 2025 - Robert Lasarzik, Elisabetta Rocca, Riccarda Rossi:
Existence and weak-strong uniqueness for damage systems in viscoelasticity
Preprint: arXiv:2409.00528, submitted 31 August 2024 - Manuel J. Arenas Jaén, Dietmar Hömberg, Robert Lasarzik: Optimal beam forming for laser materials processing
- Abramo Agosti, Robert Lasarzik, Elisabetta Rocca:
Energy-variational solutions for viscoelastic fluid models
Appeared in: Advances in Nonlinear Analysis - Moritz Ebeling-Rump, Dietmar Hömberg, Robert Lasarzik:
On a two-scale phasefield model for topology optimization
Accepted in: Discrete and Continuous Dynamical Systems Series S - Thomas Eiter, Robert Lasarzik:
Existence of energy-variational solutions to hyperbolic conservation laws
Appeared in: Advances in Nonlinear Analysis - Robert Lasarzik, Maximilian Reiter:
Analysis and numerical approximation of energy-variational solutions to the Ericksen--Leslie equations
Appeared in: Acta Applicandae Mathematicae - Dietmar Hömberg, Robert Lasarzik, Luisa Plato:
On the existence of generalized solutions to a spatio-temporal predator-prey system
Appeared in: Journal of Evolution Equations - Moritz Ebeling-Rump, Dietmar Hömberg, Robert Lasarzik:
Two-scale topology optimization with heterogeneous mesostructures based on a local volume constraint
Appeared in: Computers and Mathematics with Applications - Thomas Eiter, Katharina Hopf, Robert Lasarzik:
Weak-strong uniqueness and energy-variational solutions for a class of viscoelastoplastic fluid models
Appeared in: Advances in Nonlinear Analysis - Robert Lasarzik:
On the existence of weak solutions in the context of multidimensional incompressible fluid dynamics
Accepted in: Mathematical Methods in the Applied Sciences - Robert Lasarzik:
Analysis of a thermodynamically consistent Navier--Stokes--Cahn--Hilliard model
Appeared in: Nonlinear Analysis - Ĺubomír Baňas, Robert Lasarzik, Andreas Prohl:
Numerical analysis for nematic electrolytes
Appeared in: IMA Journal of Numerical Analysis - Dietmar Hömberg, Robert Lasarzik:
Weak entropy solutions to a model in induction hardening, existence and weak-strong uniqueness
Appeared in: Mathematical Models and Methods in Applied Sciences - Manuel J. Arenas Jaén, Dietmar Hömberg, Robert Lasarzik, Pertti Mikkonen, Thomas Petzold:
Modelling and simulation of flame cutting for steel plates with solid phases and melting
Appeared in: Journal of Mathematics in Industry - Robert Lasarzik:
Maximal dissipative solutions for incompressible fluid dynamics
Appeared in: Zeitschrift fur angewandte Mathematik und Physik - Moritz Ebeling-Rump, Dietmar Hömberg, Robert Lasarzik, Thomas Petzold:
Topology optimization subject to additive manufacturing constraints
Appeared in: Journal of Mathematics in Industry - Robert Lasarzik, Elisabetta Rocca, Giulio Schimperna:
Weak solutions and weak-strong uniqueness for a thermodynamically consistent phase-field model
Appeared in: Rendiconti Lincei Matematica e Applicazioni - Etienne Emmrich, Robert Lasarzik:
Existence of weak solutions to a dynamic model for smectic-A liquid crystals under undulations
Appeared in: IMA Journal of Applied Mathematics - Robert Lasarzik:
Approximation and optimal control of dissipative solutions to the Ericksen–Leslie system
Appeared in: Numerical Functional Analysis and Optimization - Robert Lasarzik:
Dissipative solution to the Ericksen–Leslie model equipped with the Oseen–Frank free energy
Appeared in: Zeitschrift fur angewandte Mathematik und Physik - Robert Lasarzik:
Weak-strong uniqueness for measure-valued solutions to the Ericksen–Leslie model equipped with the Oseen–Frank free energy
Appeared in: Journal of Mathematical Analysis and Applications - Etienne Emmrich, Robert Lasarzik:
Weak-strong uniqueness for the general Ericksen–Leslie system in three dimensions
Appeared in: Discrete and Continuous Dynamical Systems — A - Robert Lasarzik:
Measure-valued solutions to the Ericksen–Leslie model equipped with the Oseen–Frank energy
Appeared in: Nonlinear Analysis - Etienne Emmrich, Robert Lasarzik:
Existence of weak solutions to the Ericksen–Leslie model for a general class of free energies
Appeared in: Mathematical Methods in the Applied Sciences - Etienne Emmrich, Sabine H. L. Klapp, Robert Lasarzik:
Nonstationary models for liquid crystals: A fresh mathematical perspective
Appeared in: Journal of Non-Newtonian Fluid Mechanics
Projects
- Project manager of the MIMESIS project
- PI of Math+ project Nonlinear Electrokinetics in Anisotropic Microfluids – Analysis, Simulation, and Optimal Control
-
Project Head in the Berlin Mathematics Research Center
MATH+:
Anisotropic Microfluids -- Fluctuations, Control, Effective Models and their Numerics
Project Head: R. Lasarzik, B. Gess, S. May (TU Berlin)
March 1, 2026 - December 31, 2027 - PI of project within SPP 2410 on Hyperbolic Balance Laws in Fluid Mechanics: Complexity, Scales, Randomness. The title of the project together with Thomas Eiter is Analysis of energy-variational solutions for hyperbolic conservation laws.
- The project "Analysis of energy-variational solutions for hyperbolic conservation laws", carried out together with Thomas Eiter, was successfully defended for the second funding period within SPP 2410 CoScaRa at the Review Event in Mainz in April 2026 and was recommended for funding by the reviewers.
Teaching
- Lectures
- SoSe 2024: Partielle Differentialgleichungen III (in English)
- WiSe 2023/24: Partielle Differentialgleichungen II (in English)
- SoSe 2021: Nonlinear functional analysis and evolution equations (in English, online)
- SoSe 2019: Nonlinear functional analysis and evolution equations (in English)
- Seminars
- SoSe 2024: Seminar on ordinary differential equations
- WiSe 2023/24: Seminar on Sobolev and BV spaces
- Exercises
- SoSe 2024: Partielle Differentialgleichungen III (in English)
- WiSe 2023/24: Partielle Differentialgleichungen II (in English)
- WiSe 2016/17: Differentialgleichungen IIB
- WiSe 2015/16: Differentialgleichungen I
- WiSe 2014/15: Differentialgleichungen I
- SoSe 2011: Nichtlineare Optimierung
- Tutorials
- WiSe 2016/17: Differentialgleichungen I
- SoSe 2016: Differentialgleichungen für Ingenieure
- WiSe 2015/16: Differentialgleichungen I
- SoSe 2015: Analysis II für Mathematiker
- WiSe 2014/15: Differentialgleichungen I
- SoSe 2014: Analysis III für Ingenieure
- WiSe 2013/14: Differentialgleichungen für Ingenieure
- SoSe 2013: Mathematik für Physiker IV
- WiSe 2010/11: Lineare Algebra für Ingenieure
Research Stays
- 04/2018: University of Pavia, with Elisabetta Rocca and Giulio Schimperna
- 02/2019: University of Milan, with Monica Conti, Elisabetta Rocca, and Giulio Schimperna
- 11/2019: University of Tübingen, with Andreas Prohl
- 10/2021: University of Ulm, with Emil Wiedemann
- 02/2023: University of Pavia, with Elisabetta Rocca
- 11/2024: University of Pavia, with Elisabetta Rocca and Giulio Schimperna
- 06/2025: University of Erlangen, with Stefan Metzger
Management and Scientific Organization
- Project manager of Mathematics and Materials Science for Steel Production and Manufacturing (MIMESIS) European Industrial Doctorate program with 8 PhD students.
- 07/2019: Workshop on Mathematics and Materials Science for Steel Production and Manufacturing
- 03/2022: Organization of a Minisymposium on "Generalized solvability concepts for evolutionary PDEs and properties" together with Elisabetta Rocca at SIAM PD22
- 08/2023: Organization of a Minisymposium on "Recent Advances in the analysis and numerics of phase field methods" together with Dietmar Hömberg at ICIAM 2023 in Tokyo
- 09/2025: Mathematical Analysis of Fluid Flows by Variational Methods, WIAS Berlin
- Regularly involved in the invitation for and organization of seminars at WIAS, e.g. Group Seminar, Langenbach Seminar, FEniCS Seminar.
Additional Professional Activities
- Peer recognition: Berlin Mathematical School (BMS) Phase 1 Student; Travel grant of BMS; WIAS Young Scientist Grant; PI of two third-party funded projects; Guest professor at FU Berlin; publication On the existence of weak solutions in the context of multidimensional incompressible fluid dynamics > among most read publications in M2AS of 2023; invitation to thematic semester on Free Boundary Problems in Vienna 2025.
- Member of the WIAS Open Access and Library Commission.
- Elected representative of the scientific staff in the Scientific Advisory Board of WIAS.
- Promoting Open Science and Open Access publication by providing numerical implementations in open access using services such as GitHub and Zenodo.
- Member of DMV, EMS, and GAMM activity groups.
Education and Theses
- 13/10/2025: Defense of Habilitation thesis, FU Berlin
- 06/01/2025: Submission of Habilitation thesis, FU Berlin
- Habilitation thesis: Evolutionary variational inequalities as generalized solutions
- August 2013 -- September 2017: PhD in Mathematics at the TU Berlin under the supervision of Etienne Emmrich
- PhD Thesis: Verallgemeinerte Lösungen der Ericksen–Leslie-Gleichungen zur Beschreibung von Flüssigkristallen
- April 2012 -- July 2013: Master of Science in Mathematics at the TU Berlin
- September 2011 -- April 2012: Erasmus stay at the Ecole Polytechnique
- October 2008 -- September 2011: Bachelor of Science in Technomathematics at the TU Berlin
Contact
| lasarzik(at)wias-berlin.de | |
| Phone | +49 (0) 30 20372-466 |
| Address | Mohrenstrasse 39, 10117 Berlin |
| Office | 504 |

