9 citations · 21 across the 11 of their papers we have counts for
11 papers
Commutator estimates and Poisson bounds for Dirichlet-to-Neumann operators
A. F. M. ter Elst, E. M. Ouhabaz
We consider the Dirichlet-to-Neumann operator associated with a general elliptic operator \[ {\cal A} u = - \sum_{k,l=1}^d \partial_k (c_{kl}\, \partial_l u) + \sum_{k=1…
The Dirichlet-to-Neumann operator for divergence form problems
A. F. M. ter Elst, G. Gordon, M. Waurick
We present a way of defining the Dirichlet-to-Neumann operator on general Hilbert spaces using a pair of operators for which each one's adjoint is formally the negative of the othe…
On the -theory of -semigroups associated with second-order elliptic operators with complex singular coefficients
A. F. M. ter Elst, Vitali Liskevich, Zeev Sobol +1
We study -theory of second-order elliptic divergence type operators with complex measurable coefficients. The major aspect is that we allow complex coefficients in the main pa…
Weak and strong approximation of semigroups on Hilbert spaces
R. Chill, A. F. M. ter Elst
For a sequence of uniformly bounded, degenerate semigroups on a Hilbert space, we compare various types of convergences to a limit semigroup. Among others, we show that convergence…
On one-parameter Koopman groups
A. F. M. ter Elst, M. Lemanczyk
We characterize Koopman one-parameter -groups in the class of all unitary one-parameter -groups on as those that preserve and for which the infinit…
Dirichlet-to-Neumann maps on bounded Lipschitz domains
J. Behrndt, A. F. M. ter Elst
The Dirichlet-to-Neumann map associated to an elliptic partial differential equation becomes multivalued when the underlying Dirichlet problem is not uniquely solvable. The main ob…
Parabolic equations with dynamical boundary conditions and source terms on interfaces
A. F. M. ter Elst, Martin Meyries, Joachim Rehberg
We consider parabolic equations with mixed boundary conditions and domain inhomogeneities supported on a lower dimensional hypersurface, enforcing a jump in the conormal derivative…
Partial Gaussian bounds for degenerate differential operators II
A. F. M. ter Elst, E. M. Ouhabaz
Let be a degenerate sectorial differential operator with complex bounded mesaurable coefficients. Let $Ω\subset \mathds{R}^d$ be ope…
Partial spectral multipliers and partial Riesz transforms for degenerate operators
A. F. M. ter Elst, E. M. Ouhabaz
We consider degenerate differential operators on with real symmetric bounded measurable coeff…
Contraction semigroups on
Derek W. Robinson, A. F. M. ter Elst
If is a non-degenerate vector field on and we examine conditions for the closure of to generate a continuous semigroup on which extends to the…
Small time asymptotics of diffusion processes
A. F. M. ter Elst, Derek W. Robinson, Adam Sikora
We establish the short-time asymptotic behaviour of the Markovian semigroups associated with strongly local Dirichlet forms under very general hypotheses. Our results apply to a wi…