Contributions to Books:
R. Pruckner, H. Woracek:
"Limit behaviour of Nevanlinna functions";
in: "ASC Report 16/2019",
issued by: Institute for Analysis and Scientific Computing;
Vienna University of Technology,
We study the sets of radial or nontangential limit points towards i∞ of a Nevanlinna function q. It is shown that a subset L of C+ is the set of radial limit points of some q, if and only if it is closed, nonempty, and connected. Given L, we explicitly construct a Hamiltonian H such that L is the set of radial and nontangential limit points of the Weyl coeﬃcient qH of the canonical system with Hamiltonian H. Our method is based on a study of the continuous group action of rescaling operators on the set of all Hamiltonians.
Nevanlinna function, limit points, canonical system, Weyl coeﬃcient
Electronic version of the publication:
Created from the Publication Database of the Vienna University of Technology.