For more information about this meeting, contact Xiantao Li.

Title: | Algebraic Multigrid Methods Based on Subgraph Matching with Applications to Anisotropic Problems |

Seminar: | Computational and Applied Mathematics Colloquium |

Speaker: | Yao Chen, Department of Mathematics, Penn State |

Abstract Link: | http:// |

Abstract: |

We consider a linear system $Ax=b$ where $A$ is the Laplacian of a
weighted graph derived from an elliptic PDE with anisotropic
coefficients. We introduce a local measure $\pi_{k}$ on a set of
subgraphs which is a partition of the graph corresponding to $A$. We
prove that the convergence rate of a two grid method is bounded by a
function of $\pi_{k}$.
We then suggest a matching algorithm that optimizes the choice of
subgraphs by minimizing $\pi_{k}$ locally. The algorithm has low
complexity and is designed to use only the algebraic information of
the matrix $A$. This algorithm is used to detect the direction of
anisotropy and to setup algebraic multigrid schemes.
We also present numerical results that show the effectiveness of this
subgraph matching method
for generic anisotropic problems. |

### Room Reservation Information

Room Number: | MB106 |

Date: | 12 / 10 / 2010 |

Time: | 03:35pm - 04:25pm |