On convergence to eigenvalues and eigenvectors in the block-Jacobi EVD algorithm with dynamic ordering
On convergence to eigenvalues and eigenvectors in the block-Jacobi EVD algorithm with dynamic ordering
复制标题
动态排序块-Jacobi EVD算法中特征值和特征向量的收敛
DOI:
10.1016/j.laa.2021.03.027
复制
发表时间:
2021
影响因子:
1.1
通讯作者:
Vajtersic Marian
中科院分区:
文献类型:
--
作者:
Yamamoto Yusaku;Oksa Gabriel;Vajtersic Marian
In the block version of the classical two-sided Jacobi method for the Hermitian eigenvalue problem, the off-diagonal elements of iterated matrix A (k) converge to zero. However, this fact alone does not necessarily guarantee that A (k) converges to a fixed diagonal matrix. The same is true for the matrix of accumulated unitary transformations Q (k). We prove that under certain assumptions A (k) indeed converges to a fixed diagonal matrix, whose diagonal elements are the eigenvalues of the input matrix A. Next it is shown that for a simple eigenvalue the corresponding column of Q (k) converges to the corresponding eigenvector. For a multiple eigenvalue or a cluster of eigenvalues, we prove that the orthogonal projectors constructed from the corresponding columns of Q (k) converge to the orthogonal projector onto the eigenspace corresponding to those eigenvalues. Moreover, the appropriate convergence bounds are obtained for all discussed cases. Convergence results are also valid for the parallel block-Jacobi method with dynamic ordering. The developed theory is illustrated by numerical example.