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 of a real confluent Vandermonde matrix are established in terms of the dimension , or 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 (the largest multiplicity of distinct nodes), behaves no smaller than , or than if all nodes are nonnegative. It is not clear whether those bounds are asymptotically sharp for modest .