Kolloquium Wilhelm Killing: Prof. Dr. Martin Gander (Universität Genf): Is Optimal Really Good in Domain Decomposition ? (or why multigrid coarse spaces might not be suitable)
Thursday, 24.01.2019 16:30 im Raum M5
Domain Decomposition methods need in general a coarse correction to be
scalable, and it seems natural to use for this purpose a coarse grid
like in multigrid methods. I will show in this talk that while this
indeed suffices to make the methods scalable, and thus "optimal" in
traditional domain decomposition terminology, there are coarse
corrections that lead to much faster two level domain decomposition
methods. To explain this, I will introduce the notion of an optimal
coarse space, and optimized approximations thereof. I will finally
show that such coarse spaces can do much more than just make the
domain decomposition method scalable: they can fix problems the
underlying domain decomposition iteration has, like convergence
problems for high contrast media, divergence of the iterative
Additive Schwarz method, and even lead to a well posed Neumann-Neumann
and associated FETI domain decomposition method in function space.
Angelegt am Thursday, 27.09.2018 09:23 von cgiet_01
Geändert am Wednesday, 10.04.2019 10:42 von a_schi11
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