3 papers
math.NA2025
Real and finite field versions of Chebotarev's theorem
Tarek Emmrich, Stefan Kunis
Chebotarev's theorem on roots of unity states that all minors of the Fourier matrix of prime size are non-vanishing. This result has been rediscovered several times and proved via…
math.FA2024
Two-dimensional moment problem and Schur algorithm
Ivan Kovalyov, Stefan Kunis
We study a truncated two-dimensional moment problem in terms of the Stieltjes transform. The set of the solutions is described by the Schur step-by-step algorithm, which is based o…
math.NA2023
Two subspace methods for frequency sparse graph signals
Tarek Emmrich, Martina Juhnke-Kubitzke, Stefan Kunis
We study signals that are sparse in graph spectral domain and develop explicit algorithms to reconstruct the support set as well as partial components from samples on few vertices…