English

Stieltjes like functions and inverse problems for systems with Schr\"odinger operator

Spectral Theory 2011-11-10 v2 Functional Analysis

Abstract

A class of scalar Stieltjes like functions is realized as linear-fractional transformations of transfer functions of conservative systems based on a Schr\"odinger operator T_h in L2[a,+)L_2[a,+\infty) with a non-selfadjoint boundary condition. In particular it is shown that any Stieltjes function of this class can be realized in the unique way so that the main operator \bA\bA of a system is an accretive (*)-extension of a Schr\"odinger operator T_h. We derive formulas that restore the system uniquely and allow to find the exact value of a non-real parameter h in the definition of T_h as well as a real parameter μ\mu that appears in the construction of the elements of the realizing system. An elaborate investigation of these formulas shows the dynamics of the restored parameters h and μ\mu in terms of the changing free term γ\gamma from the integral representation of the realizable function. It turns our that the parametric equations for the restored parameter h represent different circles whose centers and radii are determined by the realizable function. Similarly, the behavior of the restored parameter μ\mu are described by hyperbolas.

Keywords

Cite

@article{arxiv.0708.0452,
  title  = {Stieltjes like functions and inverse problems for systems with Schr\"odinger operator},
  author = {Sergey Belyi and Eduard Tsekanovskii},
  journal= {arXiv preprint arXiv:0708.0452},
  year   = {2011}
}

Comments

29 pages, 9 figures

R2 v1 2026-06-21T09:04:31.159Z