19 citations · 43 across the 7 of their papers we have counts for
9 papers
Flows on Metric Graphs with General Boundary Conditions
Klaus-Jochen Engel, Marjeta Kramar Fijavž
In this note we study the generation of -semigroups by first order differential operators on $\mathrm{L}^p (\mathbb{R}_+,\mathbb{C}^{\ell})\times \mathrm{L}^p ([0,1],\mathbb{C…
Operators with Wentzell boundary conditions and the Dirichlet-to-Neumann operator
Tim Binz, Klaus-Jochen Engel
In this paper we relate the generator property of an operator with (abstract) generalized Wentzell boundary conditions on a Banach space and its associated (abstract) Diric…
Waves and Diffusion on Metric Graphs with General Vertex Conditions
Klaus-Jochen Engel, Marjeta Kramar Fijavž
We prove well-posedness for very general linear wave- and diffusion equations on compact or non-compact metric graphs allowing various different conditions in the vertices. More pr…
Exact and Positive Controllability of Boundary Control Systems
Klaus-Jochen Engel, Marjeta Kramar Fijavž
Using the semigroup approach to abstract boundary control problems we characterize the space of all exactly reachable states. Moreover, we study the situation when the controls of…
Spectral theory for structured perturbations of linear operators
Martin Adler, Klaus-Jochen Engel
We characterize the spectrum (and its parts) of operators which can be represented as G=A+BC for a simpler operator A and a structured perturbation BC. The interest in this kind of…
Perturbation of Analytic Semigroups and Applications to Partial Differential Equations
Martin Adler, Miriam Bombieri, Klaus-Jochen Engel
In a recent paper we presented a general perturbation result for generators of -semigroups. The aim of the present paper is to replace, in case the unperturbed semigroup is an…