arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2006.07473math.NAcs.NA
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计算参数相关矩阵特征值的张量-Krylov方法

Tensor-Krylov method for computing eigenvalues of parameter-dependent matrices

Koen Ruymbeek, Karl Meerbergen, Wim Michiels

摘要:

本文将残差Arnoldi法推广到求极值特征值(如最大实部,优势,.)对于矩阵依赖于参数的情况。该方法与经典Arnoldi算法的不同之处在于,在Arnoldi算法中,残差被添加到子空间中。我们开发了一个张量Krylov方法,适用于剩余Arnoldi方法(RA)的参数点的网格在同一时间。子空间包含所有这些点的近似Krylov空间。我们不是将所有参数值的残差添加到子空间,而是创建由这些残差组成的矩阵的低秩近似,并且仅将列空间添加到子空间。为了保持计算效率,需要限制子空间的维数,并且一旦子空间达到规定的最大维数就重新开始。这种方法的新颖性是双重的。首先,我们观察到在低秩近似中允许大的误差而不会减慢收敛速度,这意味着我们可以在重新开始之前进行更多的迭代。其次,我们特别注意子空间的重新启动方式,因为经典的重新启动技术在我们的情况下给出了一个太大的子空间。我们激励为什么它是足够好的,只是保持搜索的特征向量的近似。最后,我们将该算法推广到移位-反演残差Arnoldi方法,以计算接近移位$σ$的特征值。我们提供理论结果和报告数值实验。Matlab代码是公开的。

英文摘要:

In this paper we extend the Residual Arnoldi method for calculating an extreme eigenvalue (e.g. largest real part, dominant,...) to the case where the matrices depend on parameters. The difference between this Arnoldi method and the classical Arnoldi algorithm is that in the former the residual is added to the subspace. We develop a Tensor-Krylov method that applies the Residual Arnoldi method (RA) for a grid of parameter points at the same time. The subspace contains an approximate Krylov space for all these points. Instead of adding the residuals for all parameter values to the subspace we create a low-rank approximation of the matrix consisting of these residuals and add only the column space to the subspace. In order to keep the computations efficient, it is needed to limit the dimension of the subspace and to restart once the subspace has reached the prescribed maximal dimension. The novelty of this approach is twofold. Firstly, we observed that a large error in the low-rank approximations is allowed without slowing down the convergence, which implies that we can do more iterations before restarting. Secondly, we pay particular attention to the way the subspace is restarted, since classical restarting techniques give a too large subspace in our case. We motivate why it is good enough to just keep the approximation of the searched eigenvector. At the end of the paper we extend this algorithm to shift-and-invert Residual Arnoldi method to calculate the eigenvalue close to a shift $σ$ for a specific parameter dependency. We provide theoretical results and report numerical experiments. The Matlab code is publicly available.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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