English

On realization of the original Weyl-Titchmarsh functions by Shr\"odinger L-systems

Spectral Theory 2023-06-14 v2 Mathematical Physics math.MP

Abstract

We study realizations generated by the original Weyl-Titchmarsh functions m(z)m_\infty(z) and mα(z)m_\alpha(z). It is shown that the Herglotz-Nevanlinna functions (m(z))(-m_\infty(z)) and (1/m(z))(1/m_\infty(z)) can be realized as the impedance functions of the corresponding Shr\"odinger L-systems sharing the same main dissipative operator. These L-systems are presented explicitly and related to Dirichlet and Neumann boundary problems. Similar results but related to the mixed boundary problems are derived for the Herglotz-Nevanlinna functions (mα(z))(-m_\alpha(z)) and (1/mα(z))(1/m_\alpha(z)). We also obtain some additional properties of these realizations in the case when the minimal symmetric Shr\"odinger operator is non-negative. In addition to that we state and prove the uniqueness realization criteria for Shr\"odinger L-systems with equal boun\-dary parameters. A condition for two Shr\"odinger L-systems to share the same main operator is established as well. Examples that illustrate the obtained results are presented in the end of the paper.

Keywords

Cite

@article{arxiv.2006.13045,
  title  = {On realization of the original Weyl-Titchmarsh functions by Shr\"odinger L-systems},
  author = {Sergey Belyi and Eduard Tsekanovskii},
  journal= {arXiv preprint arXiv:2006.13045},
  year   = {2023}
}

Comments

29 pages, 1 figure. arXiv admin note: text overlap with arXiv:1709.07370