Allahverdiev, Bilender P.Uğurlu, EkinUgurlu, Ekin2018-09-122018-09-122016Allahverdiev B.P., Uğurlu, E. (2016). Spectral analysis of the direct sum hamiltonian operators. Quaestiones Mathematicae, 39(6), 733-750. http://dx.doi.org/10.2989/16073606.2015.11346971607-36061727-933Xhttps://doi.org/10.2989/16073606.2015.1134697Allahverdiev, Bilender P./0000-0002-9315-4652In this paper we investigate the deficiency indices theory and the selfad-joint and nonselfadjoint (dissipative, accumulative) extensions of the minimal symmetric direct sum Hamiltonian operators. In particular using the equivalence of the Lax-Phillips scattering matrix and the Sz.-Nagy-Foias characteristic function, we prove that all root (eigen and associated) vectors of the maximal dissipative extensions of the minimal symmetric direct sum Hamiltonian operators are complete in the Hilbert spaces.eninfo:eu-repo/semantics/closedAccess47A2047A4047A7547B4434L4034B4034L2547A45Hamiltonian SystemDissipative OperatorCharacteristic FunctionScattering MatrixCompleteness TheoremArticle39673375010.2989/16073606.2015.11346972-s2.0-84978636456WOS:000386443500003Q3Q2