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A convergence theory of multilevel additive Schwarz methods on unstructured meshes

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Abstract

We develop a convergence theory for two level and multilevel additive Schwarz domain decomposition methods for elliptic and parabolic problems on general unstructured meshes in two and three dimensions. The coarse and fine grids are assumed only to be shape regular, and the domains formed by the coarse and fine grids need not be identical. In this general setting, our convergence theory leads to completely local bounds for the condition numbers of two level additive Schwarz methods, which imply that these condition numbers are optimal, or independent of fine and coarse mesh sizes and subdomain sizes if the overlap amount of a subdomain with its neighbors varies proportionally to the subdomain size. In particular, we will show that additive Schwarz algorithms are still very efficient for nonselfadjoint parabolic problems with only symmetric, positive definite solvers both for local subproblems and for the global coarse problem. These conclusions for elliptic and parabolic problems improve our earlier results in [12, 15, 16]. Finally, the convergence theory is applied to multilevel additive Schwarz algorithms. Under some very weak assumptions on the fine mesh and coarser meshes, e.g., no requirements on the relation between neighboring coarse level meshes, we are able to derive a condition number bound of the orderO2 L 2), whereρ = max1l≤L(h l +l− 1)/δ l,h l is the element size of thelth level mesh,δ l the overlap of subdomains on thelth level mesh, andL the number of mesh levels.

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References

  1. R. Bank and J. Xu, A hierarchical basis multigrid method for unstructured meshes, in:10th GAMM-Seminar Kiel on Fast Solvers for Flow Problems, eds. W. Hackbusch and G. Wittum (Vieweg, Braunschweig, 1995).

    Google Scholar 

  2. R. Bank and J. Xu, An algorithm for coarsening unstructured meshes, Technical Report, Department of Mathematics, University of California, San Diego (1994).

    Google Scholar 

  3. T. Barth, Aspects of unstructured grids and finite-volume solvers for the Euler and Navier-Stokes equations, in:Special Course on Unstructured Grid Methods for Advection Dominated Flows (VKI, Belgium, 1992).

    Google Scholar 

  4. J. Bramble,Multigrid Methods, Notes on Mathematics (Pitman, 1994).

  5. J. Bramble, J. Pasciak, J. Wang and J. Xu, Convergence estimates for product iterative methods with applications to domain decomposition, Math. Comp. 57 (1991) 1–21.

    Google Scholar 

  6. J. Bramble, J. Pasciak and J. Xu, Parallel multilevel preconditioners, Math. Comp. 55 (1990) 1–21.

    Google Scholar 

  7. J. Bramble, J. Pasciak and J. Xu, The analysis of multigrid algorithms with nonnested spaces or noninherited quadratic forms, Math. Comp. 56 (1991) 1–34.

    Google Scholar 

  8. X.-C Cai, The use of pointwise interpolation in domain decomposition methods with nonnested meshes, SIAM J. Sci. Comput. 16 (1995) 250–256.

    Google Scholar 

  9. T. Chan, S. Go and J. Zou, Multilevel domain decomposition and multigrid methods for unstructured meshes: algorithms and theory, in:Proceedings of the 8th International Conference on Domain Decomposition Methods, Beijing (1995).

  10. T. Chan, S. Go and J. Zou, Boundary treatments for multilevel methods on unstructured meshes, CUHK-96-29 (103), Department of Mathematics, The Chinese University of Hong Kong (1996).

  11. T. Chan and B. Smith, Domain decomposition and multigrid methods for elliptic problems on unstructured meshes, in:Proceedings of the 7th International Conference on Domain Decomposition, eds. D. Keyes and J. Xu (American Mathematical Society, Providence, RI, 1995).

    Google Scholar 

  12. T. Chan, B. Smith and J. Zou, Overlapping Schwarz methods on unstructured meshes using nonmatching coarse grids, Numer. Math. 73 (1996) 149–167.

    Google Scholar 

  13. T. Chan, B. Smith and J. Zou, Multigrid and domain decomposition methods for unstructured meshes, in:Proceedings of the 3rd International Conference on Advances in Numerical Methods and Applications, eds. I. Dimov, Bl. Sendov and P. Vassilevski, Sofia, Bulgaria (1994) pp. 53–62.

  14. T. Chan, S. Zhang and J. Zou, Multilevel additive preconditioner for elliptic problems on nonnested meshes, Technical Report 94-44, Department of Mathematics, University of California, Los Angeles (1994).

    Google Scholar 

  15. T. Chan and J. Zou, Additive Schwarz domain decomposition methods for elliptic problems on unstructured meshes, Numer. Algorithms 8 (1994) 329–346.

    Google Scholar 

  16. T. Chan and J. Zou, Domain decomposition methods for non-symmetric parabolic problems on unstructured meshes, Technical Report 94-22, Department of Mathematics, University of California, Los Angeles (1994).

    Google Scholar 

  17. P. Ciarlet,The Finite Element Method for Elliptic Problems (North-Holland, New York, 1978).

    Google Scholar 

  18. P. Clément, Approximation by finite element functions using local regularization, RAIRO Math. Modelling Numer. Anal. R-2 (1975) 77–84.

    Google Scholar 

  19. C. Douglas and J. Douglas, A unified convergence theory for abstract multigrid or multilevel algorithms: serial and parallel, SIAM J. Numer. Anal. 30 (1993) 136–158.

    Google Scholar 

  20. C. Douglas, J. Douglas and D. Fyfe, A unifed multigrid theory for non-nested grids and/or quadrature, East-West J. Numer. Math. 2 (1995).

  21. M. Dryja and O. Widlund, An additive variant of the Schwarz alternating method for the case of many subregions, Technical Report 339, Courant Institute (1987).

  22. M. Dryja and O. Widlund, Schwarz methods of Neumann-Neumann type for three-dimensional elliptic finite element problems, Technical Report 626, Courant Institute (1993).

  23. S. Eisenstat, H. Elman and M. Schultz, Variational iterative methods for nonsymmetric systems of linear equations, SIAM J. Numer. Anal. 20 (1983) 345–357.

    Google Scholar 

  24. M. Griebel and P. Oswald, Remarks on the abstract theory of additive and multiplicative Schwarz algorithms, Technical Report TUM-19314, SFB-Bericht Nr. 342/6/93 A, Technical University of Munich (1993).

  25. P. Grisvard,Elliptic Problems in Nonsmooth Domains (Pitman Advanced Publishing Program, Boston, 1985).

    Google Scholar 

  26. P. Le Tallec, Domain decomposition methods in computational mechanics, Comput. Mech. Adv. 2 (1994) 121–220.

    Google Scholar 

  27. P. Lions, On the Schwarz alternating method I, in:1st International Symposium on Domain Decomposition Methods for Partial Differential Equations, eds. R. Glowinski, G. Golub, G. Meurant and J. Périaux (SIAM, Philadelphia, PA, 1988).

    Google Scholar 

  28. D. Mavriplis, Unstructured mesh algorithms for aerodynamic calculations, Technical Report 92-35, ICASE, NASA Langley, Virginia (1992).

    Google Scholar 

  29. M. Holst, An algebraic Schwarz theory, Technical Report, Applied Mathematics, California Institute of Technology (1995).

  30. S. Nepomnyaschikh, Domain decomposition and Schwarz methods in a subspace for the approximate solution of elliptic boundary value problems, Ph.D. Thesis, Computing Center, the Siberian Branch of the USSR Academy of Sciences, Novosibirsk (1986).

    Google Scholar 

  31. P. Oswald, On discrete norm estimates related to multilevel preconditioners in the finite element methods, in:Proceedings of International Conference on Constructive Theory of Functions, eds. K. Ivanov and B. Sendov, Varna'91, Sofia (1992) pp. 203–241.

  32. L. Scott and S. Zhang, Finite element interpolation of nonsmooth functions satisfying boundary conditions, Math. Comp. 54 (1990) 483–493.

    Google Scholar 

  33. L. Scott and S. Zhang, Higher-dimensional nonnested multigrid methods, Math. Comp. 58 (1992) 457–466.

    Google Scholar 

  34. B. Smith, P. Bjørstad and W. Gropp,Domain Decomposition: Parallel Multilevel Methods for Elliptic Partial Differential Equations (Cambridge University Press, Cambridge, 1996).

    Google Scholar 

  35. E. Stein,Singular Integrals and Differentiability Properties of Functions (Princeton University Press, Princeton, 1970).

    Google Scholar 

  36. J. Xu, Iterative methods by space decomposition and subspace correction, SIAM Review 34 (1992) 581–613.

    Google Scholar 

  37. J. Xu, A new class of iterative methods for nonselfadjoint or indefinite problems, SIAM J. Numer. Anal. 29 (1992) 303–319.

    Google Scholar 

  38. J. Xu and X.-C. Cai, A preconditioned GMRES method for nonsymmetric or indefinite problems, Math. Comp. 59 (1992) 311–319.

    Google Scholar 

  39. J. Xu and J. Zou, Non-overlapping domain decomposition methods, MATH-96-19 (93), Department of Mathematics, The Chinese University of Hong Kong (1996).

  40. S. Zhang, Optimal-order nonnested multigrid methods for solving finite element equations I: on quasi-uniform meshes, Math. Comp. 55 (1990) 23–36.

    Google Scholar 

  41. S. Zhang, Optimal-order nonnested multigrid methods for solving finite element equations II: on non-quasi-uniform meshes, Math. Comp. 55 (1990) 439–450.

    Google Scholar 

  42. X. Zhang, Multilevel Schwarz methods, Numer. Math. 63 (1992) 521–539.

    Google Scholar 

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Communicated by G. Meurant

The work was partially supported by the NSF under contract ASC 92-01266, and ONR under contract ONR-N00014-92-J-1890. The second author was also partially supported by HKRGC grants no. CUHK 316/94E and the Direct Grant of CUHK.

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Chan, T.F., Zou, J. A convergence theory of multilevel additive Schwarz methods on unstructured meshes. Numer Algor 13, 365–398 (1996). https://doi.org/10.1007/BF02207701

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