[petsc-users] Null space for the Stokes laplacian operator

[Matthew Knepley]

On Tue, Jan 14, 2020 at 3:52 PM Salazar De Troya, Miguel via petsc-users <
petsc-users at mcs.anl.gov> wrote:

> GAMG needs the kernel of the operator to build the coarsening spaces. In
> elasticity, these are the translation and the rotations. If I were to solve
> the Stokes problem using the Schur complement approach and I wanted to use
> GAMG for the Laplacian of the velocity block, should I pass the kernel as
> well? Is this kernel made of translation and rotation (of the velocity)? I
> haven’t found anything like this in the literature, hence my question.
>

The kernel should be just the constant functions, which all AMG
implementations include by default. You can tell
people only solve the Laplacian.

  Thanks,

     Matt


> Thanks
>
> Miguel
>
>
>
> Miguel A. Salazar de Troya
>
> Postdoctoral Researcher, Lawrence Livermore National Laboratory
>
> B141
>
> Rm: 1085-5
>
> Ph: 1(925) 422-6411
>


-- 
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which their
experiments lead.
-- Norbert Wiener

https://www.cse.buffalo.edu/~knepley/ <http://www.cse.buffalo.edu/~knepley/>
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