7–11 Sept 2026
Humboldt Universität zu Berlin
Europe/Berlin timezone

A free boundary problem with non-local obstacle

10 Sept 2026, 12:00
30m
Main Building/Floor 1-Room 2097 - Lecture Hall (HU (Main Building))

Main Building/Floor 1-Room 2097 - Lecture Hall

HU (Main Building)

HU Berlin Main Building Unter den Linden 6 10117 Berlin
142
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Degenerate PDEs and Free Boundary Problems Degenerate PDEs and Free Boundary Problems

Speaker

Dr Hayk Mikayelyan (University of Nottingham Ningbo China)

Description

Consider the cylindrical domain $\Omega=D\times(0,1)$ and the convex functional
$$ \int_\Omega \frac{1}{2}|\nabla U(x)|^2dx +\int_D V(x')^+\,dx', $$ with nonlocal obstacle acting on function $V(x')=\int_0^1 U(x', t) dt $. We show that the unique minimizer solves the equation $$ \Delta U(x',x_n) = \chi_{\{V>0\}}(x') + \chi_{\{V=0\}}(x') [\partial_\nu U (x',0) + \partial_\nu U (x',1)], $$ where $\partial_\nu U$ is the exterior normal derivative of $U$.

Several further regularity results are proven. It is shown that the comparison principle does not hold for minimizers, which makes numerical approximation somewhat challenging.

Author

Dr Hayk Mikayelyan (University of Nottingham Ningbo China)

Presentation materials

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