Zobrazeno 1 - 10
of 143
pro vyhledávání: '"Jussi, Behrndt"'
This open access book presents a comprehensive survey of modern operator techniques for boundary value problems and spectral theory, employing abstract boundary mappings and Weyl functions. It includes self-contained treatments of the extension theor
Publikováno v:
Bulletin of Mathematical Sciences, Vol 8, Iss 1, Pp 49-80 (2017)
Abstract The principal aim of this paper is to derive an abstract form of the third Green identity associated with a proper extension T of a symmetric operator S in a Hilbert space $$\mathfrak {H}$$ H , employing the technique of quasi boundary tripl
Externí odkaz:
https://doaj.org/article/dd1ff31cc7fb4c198f7f28d7775da1ea
Autor:
Jussi Behrndt, Andrii Khrabustovskyi
Publikováno v:
Mathematische Nachrichten. 295:1063-1095
Publikováno v:
Opuscula Mathematica, Vol 36, Iss 6, Pp 717-734 (2016)
Let \(A\) and \(B\) be selfadjoint operators in a Krein space. Assume that the resolvent difference of \(A\) and \(B\) is of rank one and that the spectrum of \(A\) consists in some interval \(I\subset\mathbb{R}\) of isolated eigenvalues only. In the
Externí odkaz:
https://doaj.org/article/d6489a1716dc47bca48e4cb4092a71eb
In the last decade there has been a growing interest in superoscillations in various fields of mathematics, physics and engineering. However, while in applications as optics the local oscillatory behaviour is the important property, some convergence
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::13b39f4e9762558becadf2cc1bd403c6
Publikováno v:
Transactions of the American Mathematical Society. 375:799-845
We prove a generalized Birman-Schwinger principle in the non-self-adjoint context. In particular, we provide a detailed discussion of geometric and algebraic multiplicities of eigenvalues of the basic operator of interest (e.g., a Schrodinger operato
Publikováno v:
Integral Equations and Operator Theory. 94
In this note the two dimensional Dirac operator $$A_\eta $$ A η with an electrostatic $$\delta $$ δ -shell interaction of strength $$\eta \in {\mathbb {R}}$$ η ∈ R supported on a straight line is studied. We observe a spectral transition in the
Publikováno v:
Advances in Mathematics. 422:109022
We develop relative oscillation theory for general Sturm-Liouville differential expressions of the form \[ \frac{1}{r}\left(-\frac{\mathrm d}{\mathrm dx} p \frac{\mathrm d}{\mathrm dx} + q\right) \] and prove perturbation results and invariance of es
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4ebfa670c65bb63b0ca1417b2d9f4412
http://arxiv.org/abs/2203.08938
http://arxiv.org/abs/2203.08938
Publikováno v:
EMS Newsletter. :25-30