3 papers
math.NA2021
Multivariate Vandermonde matrices with separated nodes on the unit circle are stable
Stefan Kunis, Dominik Nagel, Anna Strotmann
We prove explicit lower bounds for the smallest singular value and upper bounds for the condition number of rectangular, multivariate Vandermonde matrices with scattered nodes on t…
math.NA2019
On the smallest singular value of multivariate Vandermonde matrices with clustered nodes
Stefan Kunis, Dominik Nagel
We prove lower bounds for the smallest singular value of rectangular, multivariate Vandermonde matrices with nodes on the complex unit circle. The nodes are ``off the grid'', group…
math.NA2018
On the condition number of Vandermonde matrices with pairs of nearly-colliding nodes
Stefan Kunis, Dominik Nagel
We prove upper and lower bounds for the spectral condition number of rectangular Vandermonde matrices with nodes on the complex unit circle. The nodes are "off the grid", pairs of…