Welcome

Welcome to my webpage. I am a PostDoc at the Weierstrass Institute for Applied Analysis and Stochastics, Berlin, and member of the research group Nichtlineare Optimierung und Inverse Probleme of Dietmar Hömberg.

My research mainly focuses on the theory of generalized solutions their approximation and optimal control.

Teaching

• Currently (WiSe 2023/24), I am teaching the course Partial Differential Equations II at FU Berlin.
• Lecture Description: Differential equations are a fundamental tool to model processes in science and technology. In this lecture we will first consider fixed-point theorems and use them to show solvability of nonlinear differential equations. Building on linear elliptic theory and Lax-Milgram's lemma, we will prove Browder--Minty's theorem, a general existence result for monotone operators. The generalization to pseudomonotone operators will allow us to treat the stationary Navier--Stokes equations and other examples. In the last part of the course, we will turn to nonsmooth problems and study maximal monotone operators. Prerequisites: Analysis I-III, Linear Algebra

	time	room
lecture	Monday 12-14	1.3.21 Seminarraum T1 (Arnimallee 14)
lecture	Wednesday 10-12	A6/SR 009 Seminarraum
exercise	Wednesday 12-14	A6/SR 025/026 Seminarraum

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-variaitonal solutions
• Phase-field models
• Viscoelastic fluids

Publications

• 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
• 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
• Robert Lasarzik: Measure-valued solutions to the Ericksen–Leslie model equipped with the Oseen–Frank energy
  Appeared in: Nonlinear Analysis
• 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: 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
• 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: Approximation and optimal control of dissipative solutions to the Ericksen–Leslie system
  Appeared in: Numerical Functional Analysis and Optimization
• 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, Elisabetta Rocca, Giulio Schimperna: Weak solutions and weak-strong uniqueness for a thermodynamically consistent phase-field model
  Appeared in: Rendiconti Lincei Matematica e Applicazioni
• 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: Maximal dissipative solutions for incompressible fluid dynamics
  Appeared in: Zeitschrift fur angewandte Mathematik und Physik
• 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
• 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
• Ĺubomír Baňas, Robert Lasarzik, Andreas Prohl: Numerical analysis for nematic electrolytes
  Appeared in: IMA Journal of Numerical Analysis
• Robert Lasarzik: Analysis of a thermodynamically consistent Navier--Stokes--Cahn--Hilliard model
  Appeared in: Nonlinar 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
• 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
• 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
• 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
• Robert Lasarzik, Maximilian Reiter: Analysis and numerical approximation of energy-variational solutions to the Ericksen--Leslie equations
  Appeared in: Acta Applicandae Mathematicae
• Thomas Eiter, Robert Lasarzik: Existence of energy-variational solutions to hyperbolic conservation laws
• 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

Projects

• Project manager of the MIMESIS project
• PI of Math+ project Nonlinear Electrokinetics in Anisotropic Microfluids – Analysis, Simulation, and Optimal Control
• PI of project within SPP 2410 on Hyperbolic Balance Laws in Fluid Mechanics: Complexity, Scales, Randomness. The title of the project togerther with Thomas Eiter is Analysis of energy-variational solutions for hyperbolic conservation laws.

Education and Theses

• 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 to -- April 2012 Erasmus stay at the Ecole Polytechnique
• October 2008 -- September 2011 Bachelor of science in Technomathematics at the TU Berlin

Contact