Thursday, Nov. 13, 9:30 am in MTH 3206, University of Maryland,
College Park
Numerical solution of elliptic problems with highly discontinuous
coefficient
Prof. Andrew Knyazev
Department of Mathematics,
University of Colorado at Denver,
Denver, CO 80217-3364
We consider, as an example, a parametric family of boundary value problems
for the diffusion equation with the diffusion coefficient equal to a small
constant in a subdomain. Such problems are not uniformly well-posed when
the constant gets small. However, we suggest a natural implicit splitting of
the problem into two well-posed problems. Using this idea, we prove a uniform
convergence of a standard preconditioned iterative method with a special
initial guess. In all our arguments we use a natural parameter-independent
Sobolev norm, not the energy norm. We also discuss FEM error estimates for
such problems, and mention some results for the mixed formulation of the
problem.
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