首页 | 本学科首页   官方微博 | 高级检索  
     


Lower bounds for the condition number of a real confluent Vandermonde matrix
Authors:Ren-Cang Li.
Affiliation:Department of Mathematics, University of Kentucky, Lexington, Kentucky 40506
Abstract:Lower bounds on the condition number $ kappa_p(V_{{c}})$ of a real confluent Vandermonde matrix $ V_{{c}}$ are established in terms of the dimension $ n$, or $ n$ and the largest absolute value among all nodes that define the confluent Vandermonde matrix and the interval that contains the nodes. In particular, it is proved that for any modest $ k_{max}$ (the largest multiplicity of distinct nodes), $ kappa_p(V_{{c}})$ behaves no smaller than $ {mathcal O}_n((1+sqrt 2,)^n)$, or than $ {mathcal O}_n((1+sqrt 2,)^{2n})$ if all nodes are nonnegative. It is not clear whether those bounds are asymptotically sharp for modest $ k_{max}$.

Keywords:Optimal condition number   Vandermonde matrix   confluent Vandermonde matrix   Chebyshev polynomials
点击此处可从《Mathematics of Computation》浏览原始摘要信息
点击此处可从《Mathematics of Computation》下载全文
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号