16 citations · 27 across the 8 of their papers we have counts for
9 papers
The essential norm of multiplication operators on
Jürgen Voigt
We show that the formula for the essential norm of a multiplication operator on , for , also holds for . We also provide a proof for the formula which works s…
On Hausdorff measure and an inequality due to Maz'ya
Hendrik Vogt, Jürgen Voigt
We give an "elementary" proof of an inequality due to Maz'ya. As a prerequisite we prove an approximation property for the Hausdorff measure. We also comment on the relations betwe…
Holomorphic families of forms, operators and -semigroups
Hendrik Vogt, Jürgen Voigt
If is a holomorphic function with values in the sectorial forms in a Hilbert space, then the associated operator valued function is resolvent holomorp…
Dirichlet forms for singular diffusion on graphs
Christian Seifert, Jürgen Voigt
We describe operators driving the time evolution of singular diffusion on finite graphs whose vertices are allowed to carry masses. The operators are defined by the method of quadr…
Perturbations of Positive Semigroups on AM-Spaces
A. Bátkai, B. Jacob, J. Voigt +1
We consider positive perturbations of positive semigroups on AM-spaces and prove a result which is the dual counterpart of a famous perturbation result of Desch in AL-spaces. As an…
Bands in -spaces
Hendrik Vogt, Jürgen Voigt
For a general measure space , it is shown that for every band in there exists a decomposition such that $M=L_p(μ')=\{f\in L_p(μ);f=0\ μ^…
A note on absorption semigroups and regularity
Amir Manavi, Hendrik Vogt, Jürgen Voigt
It is shown that, in the theory of absorption semigroups, two possible ways of defining regularity for absorption rates are in fact equivalent.
Bound States for Nano-Tubes with a Dislocation
Rainer Hempel, Martin Kohlmann, Marko Stautz +1
As a model for an interface in solid state physics, we consider two real-valued potentials and on the cylinder or tube $S=\mathbb R \times (\mathbb R/\mathbb Z)…
Boundary systems and (skew-)self-adjoint operators on infinite metric graphs
Carsten Schubert, Christian Seifert, Jürgen Voigt +1
We generalize the notion of Lagrangian subspaces to self-orthogonal subspaces with respect to a (skew-)symmetric form, thus characterizing (skew-)self-adjoint and unitary operators…