Complex Analysis and Operator Theory ( IF 0.7 ) Pub Date : 2020-11-25 , DOI: 10.1007/s11785-020-01056-5 S. Belyi , E. Tsekanovskiĭ
We study realizations generated by the original Weyl–Titchmarsh functions \(m_\infty (z)\) and \(m_\alpha (z)\). It is shown that the Herglotz–Nevanlinna functions \((-\,m_\infty (z))\) and \((1/m_\infty (z))\) can be realized as the impedance functions of the corresponding Shrödinger 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 \((-\,m_\alpha (z))\) and \((1/m_\alpha (z))\). We also obtain some additional properties of these realizations in the case when the minimal symmetric Shrödinger operator is non-negative. In addition to that we state and prove the uniqueness realization criteria for Shrödinger L-systems with equal boundary parameters. A condition for two Shrödinger 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.
中文翻译:
用ShrödingerL系统实现原始Weyl-Titchmarsh函数
我们研究由原始的Weyl–Titchmarsh函数\(m_ \ infty(z)\)和\(m_ \ alpha(z)\)生成的实现。结果表明,可以将Herglotz–Nevanlinna函数\((-\,m_ \ infty(z))\)和\((1 / m_ \ infty(z))\)作为相应的Shrödinger的阻抗函数来实现L系统共享相同的主要耗散算子。这些L系统是明确提出的,并且与Dirichlet和Neumann边界问题有关。对于Herglotz–Nevanlinna函数\((-\,m_ \ alpha(z))\)和\((1 / m_ \ alpha(z))\)得出相似的结果,但与混合边界问题有关。在最小对称Shrödinger运算符为非负数的情况下,我们还获得了这些实现的其他一些属性。除此之外,我们陈述并证明具有相等边界参数的ShrödingerL系统的唯一性实现标准。还建立了两个ShrödingerL系统共享同一主算子的条件。本文末尾提供了说明获得的结果的示例。