English

On dB spaces with nondensely defined multiplication operator and the existence of zero-free functions

Mathematical Physics 2020-07-23 v3 math.MP

Abstract

In this work we consider de Branges spaces where the multiplication operator by the independent variable is not densely defined. First, we study the canonical selfadjoint extensions of the multiplication operator as a family of rank-one perturbations from the viewpoint of the theory of de Branges spaces. Then, on the basis of the obtained results, we provide new necessary and sufficient conditions for a real, zero-free function to lie in a de Branges space.

Keywords

Cite

@article{arxiv.1304.5277,
  title  = {On dB spaces with nondensely defined multiplication operator and the existence of zero-free functions},
  author = {Luis O. Silva and Julio H. Toloza},
  journal= {arXiv preprint arXiv:1304.5277},
  year   = {2020}
}

Comments

13 pages, no fugures. Theorem and remark have been added, typographical erros corrected