On completeness of weak eigenfunctions for multi-interval Sturm-Liouville equations with boundary-interface conditions       
Yazarlar (1)
Doç. Dr. Hayati OLĞAR Tokat Gaziosmanpaşa Üniversitesi, Türkiye
Makale Türü Açık Erişim Özgün Makale
Makale Alt Türü SSCI, AHCI, SCI, SCI-Exp dergilerinde yayınlanan tam makale
Dergi Adı Demonstratio Mathematica
Dergi ISSN 0420-1213 Wos Dergi Scopus Dergi
Dergi Tarandığı Indeksler SCI-Expanded
Dergi Grubu Q1
Makale Dili İngilizce
Basım Tarihi 03-2023
Cilt No 56
Sayı 1
Sayfalar 1 / 10
DOI Numarası 10.1515/dema-2022-0210
Makale Linki https://www.degruyter.com/document/doi/10.1515/dema-2022-0210/html
Özet
The goal of this study is to analyse the eigenvalues and weak eigenfunctions of a new type of multi-interval Sturm-Liouville problem (MISLP) which differs from the standard Sturm-Liouville problems (SLPs) in that the Strum-Liouville equation is defined on a finite number of non-intersecting subintervals and the boundary conditions are set not only at the endpoints but also at finite number internal points of interaction. For the self-adjoint treatment of the considered MISLP, we introduced some self-adjoint linear operators in such a way that the considered multi-interval SLPs can be interpreted as operator-pencil equation. First, we defined a concept of weak solutions (eigenfunctions) for MISLPs with interface conditions at the common ends of the subintervals. Then, we found some important properties of eigenvalues and corresponding weak eigenfunctions. In particular, we proved that the spectrum is discrete and the system of weak eigenfunctions forms a Riesz basis in appropriate Hilbert space.
Anahtar Kelimeler
boundary and interface conditions | completeness | multi-interval Sturm-Liouville problems | weak eigenfunctions