On Matrix-Valued Herglotz Functions
| dc.creator | Gesztesy, Fritz | |
| dc.creator | Tsekanovskii, Eduard | |
| dc.date | 1997-12-11 | |
| dc.date.accessioned | 2026-07-07T03:24:40Z | |
| dc.date.available | 2026-07-07T03:24:40Z | |
| dc.description | We provide a comprehensive analysis of matrix-valued Herglotz functions and illustrate their applications in the spectral theory of self-adjoint Hamiltonian systems including matrix-valued Schrödinger and Dirac-type operators. Special emphasis is devoted to appropriate matrix-valued extensions of the well-known Aronszajn-Donoghue theory concerning support properties of measures in their Nevanlinna-Riesz-Herglotz representation. In particular, we study a class of linear fractional transformations M_A(z) of a given n \times n Herglotz matrix M(z) and prove that the minimal support of the absolutely continuos part of the measure associated to M_A(z) is invariant under these linear fractional transformations. Additional applications discussed in detail include self-adjoint finite-rank perturbations of self-adjoint operators, self-adjoint extensions of densely defined symmetric linear operators (especially, Friedrichs and Krein extensions), model operators for these two cases, and associated realization theorems for certain classes of Herglotz matrices. | |
| dc.description | LaTeX | |
| dc.identifier | https://arxiv.org/abs/funct-an/9712004 | |
| dc.identifier | http://arxiv.org/abs/funct-an/9712004 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/33418 | |
| dc.subject | Functional Analysis | |
| dc.subject | Mathematical Physics | |
| dc.subject | 30D50, 30E20, 47A10 (primary) 47A45 (secondary) | |
| dc.title | On Matrix-Valued Herglotz Functions | |
| dc.type | text |