3 papers
math.CV2005
Boundary Nevanlinna--Pick interpolation problems for generalized Schur functions
Vladimir Bolotnikov, Alexander Kheifets
Three boundary Nevanlinna-Pick interpolation problems at finitely many points are formulated for generalized Schur functions. For each problem, the set of all solutions is parametr…
math.CV2002
Functions with Pick matrices having bounded number of negative eigenvalues
V. Bolotnikov, A. Kheifets, L. Rodman
A class is studied of complex valued functions defined on the unit disk (with a possible exception of a discrete set) with the property that all their Pick matrices have not more t…
math.SP2002
The "Action" Variable is not an Invariant for the Uniqueness in the Inverse Scattering Problem
A. Kheifets, P. Yuditskii
We give a simple example of non-uniqueness in the inverse scattering for Jacobi matrices: roughly speaking -matrix is analytic. Then, multiplying a reflection coefficient by an…