Upcoming Events
- March 16 – 18, 2026 (WIAS-ESH)
- Workshop/Konferenz: Workshop Optimal Transport and Noise: OT Meets (S)PDEs
more ... Location
Weierstraß-Institut, Anton-Wilhelm-Amo-Str. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal
Host
Technische Universität Berlin
WIAS Berlin
- Monday, 23.03.2026, 14:30 (WIAS-ESH)
- Joint Research Seminar on Nonsmooth Variational Problems and Operator Equations / Mathematical Optimization
Xiao Meng, Hong Kong Baptist University, Hong Kong:
Well-posedness and optimal control of a PDE-ODE spatial-network model on metric graphs and sub-domains
more ... Location
Weierstraß-Institut, Anton-Wilhelm-Amo-Str. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal
Abstract
Mathematical modeling of dynamics on metric graphs arises in various contexts, from epidemic dynamics to chemical transport in fractured media. Diffusion processes and interactions within complex topological structures pose significant analytical challenges. In practical scenarios, effective intervention strategies are also critical. In this work, we analyze a coupled PDE-ODE system defined on a hybrid structure. The model is formulated as a nonlinear system with junction conditions that capture diffusion in subdomains, along edges, and at vertices. The well-posedness of the system, including the existence, uniqueness, and regularity of solutions, is established via Galerkin approximations and energy estimates. Building on these coupled dynamics, we extend our approach to optimal control. In this framework, a quadratic cost functional penalizes deviations of the state variables from desired targets while accounting for the energetic cost of control actions. Our analysis demonstrates that the state-to-control mapping is Fr´echet differentiable, and we derive the corresponding linearized system and adjoint system, along with the first-order optimality conditions.
Further Informations
Joint Research Seminar on Nonsmooth Variational Problems and Operator Equations
Host
WIAS Berlin
- Wednesday, 15.04.2026, 11:30 (WIAS-406)
- Seminar Interacting Random Systems
Willem van Zuijlen, WIAS Berlin:
tba
more ... Location
Weierstraß-Institut, Anton-Wilhelm-Amo-Str. 39, 10117 Berlin, 4. Etage, Weierstraß-Hörsaal (Raum: 406)
Abstract
tba
Further Informations
Seminar Interactin Random Systems
Host
WIAS Berlin
- Wednesday, 15.04.2026, 14:15 (WIAS-ESH)
- Berliner Oberseminar „Nichtlineare partielle Differentialgleichungen” (Langenbach-Seminar)
Prof. Dr. Pierluigi Colli, Università di Pavia, Italien:
Well-posedness and optimal velocity control of a Brinkman--Cahn--Hilliard system with curvature effects
more ... Location
Weierstraß-Institut, Anton-Wilhelm-Amo-Str. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal
Abstract
Diffuse-interface models for multiphase flows have attracted considerable interest due to their ability to describe complex interfacial dynamics, including curvature effects, within a unified and energetically consistent framework. In this talk, we present joint results for a Brinkman--Cahn--Hilliard system coupling a sixth-order phase-field evolution with a Brinkman-type momentum equation with variable shear viscosity. The Cahn--Hilliard equation includes a nonconservative source term modeling mass exchange, while the momentum equation involves a forcing term that is not divergence-free. We prove the existence of weak solutions in a divergence-free variational framework and, in the case of constant mobility and shear viscosity, establish uniqueness and continuous dependence on the forcing. We also analyze the Darcy limit and obtain existence results for the corresponding reduced system. Finally, we consider an optimal control problem with distributed velocity control, prove the existence of optimal controls, show the Fréchet differentiability of the control-to-state operator, and derive first-order necessary optimality conditions via an adjoint system.
Further Informations
Oberseminar “Nichtlineare partielle Differentialgleichungen” (Langenbach-Seminar)
Host
Humboldt-Universität zu Berlin
WIAS Berlin
- Thursday, 16.04.2026, 14:15 (WIAS-ESH)
- Berliner Oberseminar „Nichtlineare partielle Differentialgleichungen” (Langenbach-Seminar)
Prof. Dr. José A. Carrillo de la Plata, University of Oxford, GB:
Primal dual methods for Wasserstein gradient flows
more ... Location
Weierstraß-Institut, Anton-Wilhelm-Amo-Str. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal
Abstract
Many nonlinear evolution equations arising in porous media flow, materials science, and collective behavior can be understood as gradient flows in the space of probability measures. In this talk, we present a new numerical framework that exploits this variational structure by combining ideas from optimal transport with modern operator splitting methods. Our approach is based on the Jordan--Kinderlehrer--Otto (JKO) scheme and the Benamou--Brenier formulation of the Wasserstein distance, which together recast the solution of certain nonlinear, nonlocal PDEs as a sequence of convex optimization problems. We show how these problems can be solved efficiently using a recent primal-dual splitting algorithm with rigorous convergence guarantees. We illustrate the method with numerical examples for nonlinear PDEs and Wasserstein geodesics. We conclude by outlining extensions to more general nonlinear mobilities and transport costs, highlighting the flexibility of the approach and its potential for a wide range of applications.
Further Informations
Oberseminar “Nichtlineare partielle Differentialgleichungen” (Langenbach-Seminar)
Host
Humboldt-Universität zu Berlin
WIAS Berlin
- Thursday, 23.04.2026, 10:00 (WIAS-ESH)
- Forschungsseminar Mathematische Modelle der Photonik
Lasse Ermoneit, WIAS Berlin:
Epitaxial profile optimization in Si/SiGe heterostructures: Engineering valley splitting for spin qubits
more ... Location
Weierstraß-Institut, Anton-Wilhelm-Amo-Str. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal
Further Informations
Forschungsseminar Mathematische Modelle der Photonik
Host
WIAS Berlin
- Wednesday, 27.05.2026, 11:30 (WIAS-406)
- Seminar Interacting Random Systems
David Dereudre, University of Lille:
tba
more ... Location
Weierstraß-Institut, Anton-Wilhelm-Amo-Str. 39, 10117 Berlin, 4. Etage, Weierstraß-Hörsaal (Raum: 406)
Abstract
tba
Further Informations
Seminar Interactin Random Systems
Host
WIAS Berlin
- June 1 – 5, 2026 (WIAS-ESH)
- Workshop/Konferenz: ESGI 194 - The Berlin Study Group with Industry
more ... Location
Weierstraß-Institut, Anton-Wilhelm-Amo-Str. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal
Host
WIAS Berlin
- July 6 – 8, 2026 (WIAS-ESH)
- Workshop/Konferenz: Spreading Dynamics in Random Environment
more ... Location
Weierstraß-Institut, Anton-Wilhelm-Amo-Str. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal
Host
WIAS Berlin