Some spectral problems of dissipative q-Sturm–Liouville operators in limit-point case for q > 1


Allahverdiev B. P., AYGAR KÜÇÜKEVCİLİOĞLU Y.

Filomat, vol.38, no.22, pp.7693-7705, 2024 (SCI-Expanded, Scopus)

  • Publication Type: Article / Article
  • Volume: 38 Issue: 22
  • Publication Date: 2024
  • Doi Number: 10.2298/fil2422693a
  • Journal Name: Filomat
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.7693-7705
  • Keywords: Characteristic func-tion, Completeness of the root functions, Dissipative operator, q-Sturm–Liouville equation, Self-adjoint dilation, Weyl–Titchmarsh function
  • Ankara University Affiliated: Yes

Abstract

The main purpose of this study is to investigate dissipative singular q-Sturm–Liouville operators in a suitable Hilbert space and to examine the extensions of a minimal symmetric operator in limit-point case. We make a self-adjoint dilation of the dissipative operator together with its incoming and outgoing spectral components, which satisfy determining the scattering function of the dilation via Lax-Phillips theory. We also construct a functional model of the maximal dissipative operator by using the incoming spectral representation and we find its characteristic function in terms of the Weyl–Titchmarsh function of the self-adjoint q-Sturm–Liouville operator whenever q > 1. Furthermore, we present a theorem about the completeness of the system of eigenfunctions and associated functions (or root functions) of the dissipative q-Sturm–Liouville operator.