TY - JOUR T1 - A Cascadic Multigrid Algorithm for Computing the Fiedler Vector of Graph Laplacians AU - Urschel , John C. AU - Xu , Jinchao AU - Hu , Xiaozhe AU - Zikatanov , Ludmil T. JO - Journal of Computational Mathematics VL - 2 SP - 209 EP - 226 PY - 2015 DA - 2015/04 SN - 33 DO - http://doi.org/10.4208/jcm.1412-m2014-0041 UR - https://global-sci.org/intro/article_detail/jcm/9837.html KW - Graph Laplacian, Cascadic multigrid, Fiedler vector, Elliptic eigenvalue problems. AB -
In this paper, we develop a cascadic multigrid algorithm for fast computation of the Fiedler vector of a graph Laplacian, namely, the eigenvector corresponding to the second smallest eigenvalue. This vector has been found to have applications in fields such as graph partitioning and graph drawing. The algorithm is a purely algebraic approach based on a heavy edge coarsening scheme and pointwise smoothing for refinement. To gain theoretical insight, we also consider the related cascadic multigrid method in the geometric setting for elliptic eigenvalue problems and show its uniform convergence under certain assumptions. Numerical tests are presented for computing the Fiedler vector of several practical graphs, and numerical results show the efficiency and optimality of our proposed cascadic multigrid algorithm.