Spectral Theory of the Klein-Gordon Equation in Krein Spaces

Autor: Christiane Tretter, Branko Najman, Heinz Langer

Publikováno v: Langer, Heinz; Najman, Branko; Tretter, Christiane (2008). Spectral theory of the Klein-Gordon equation in Krein spaces. Proceedings of the Edinburgh Mathematical Society, 51(3), pp. 711-750. Cambridge: Cambridge University Press 10.1017/S0013091506000150

In this paper the spectral properties of the abstract Klein–Gordon equation are studied. The main tool is an indefinite inner product known as the charge inner product. Under certain assumptions on the potential V, two operators are associated with

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a527655f770841a98fad8d6d3f50c2f4
http://doc.rero.ch/record/290540/files/S0013091506000150.pdf

A variational principle for eigenvalues of pencils of Hermitian matrices

Autor: Qiang Ye, Paul Binding, Branko Najman

Publikováno v: Integral Equations and Operator Theory. 35:398-422

LetH=(A, B) be a pair of HermitianN×N matrices. A complex number λ is an eigenvalue ofH ifdet(A−λB)=0 (we include λ=∞ ifdetB=0). For nonsingularH (i.e., for which some λ is not an eigenvalue), we show precisely which eigenvalues can be chara

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::f3157cafee63b37815722e1cc6104936
https://doi.org/10.1007/bf01228041

The Asymptotic Behavior of the Eigenvalues of a Singularly Perturbed Linear Pencil

Autor: Branko Najman

Publikováno v: SIAM Journal on Matrix Analysis and Applications. 20:420-427

The pencil $\widetilde{T}(\lambda,\varepsilon)=\varepsilon\lambda^{2}I + \lambda C+K,$ a singular perturbation of the linear pencil $\widetilde{T}(\lambda,0)=\lambda C+K,$ is considered, and the asymptotic behavior of its large eigenvalues (i.e.,\ th

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::e208cdbc3fb06f0bc933584b03ce206f
https://doi.org/10.1137/s0895479896299949

Preservation of the range under perturbations of an operator

Autor: Branko Ćurgus, Branko Najman

Publikováno v: Proceedings of the American Mathematical Society. 125:2627-2631

A sufficient condition for the stability of the range of a positive operator in a Hilbert space is given. As a consequence, we get a class of additive perturbations which preserve regularity of the critical point 0 of a positive operator in a Krein s

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::2b2949130b5867690379a7c9c9df9a80
https://doi.org/10.1090/s0002-9939-97-03840-9

Nondegenerate Jordan subspaces of self-adjoint operators in indefinite spaces

Autor: J. Bognár, Paul Binding, T.Ja. Azizov, Branko Najman

Publikováno v: Linear Algebra and its Applications. 207:37-48

Let A be a self-adjoint operator on a finite dimentional inner product space K which is nondegenerate (i.e., K ∩ K ⊥ = 0). For a fixed Jordan basis B of A, we examine sets of Jordan chains in B which span nondegenerate subspaces. An example is th

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0b7375dd2bea03049cbf424e9a78c8d1
https://doi.org/10.1016/0024-3795(94)90003-5