Abstract:
The sets of radial or nontangential limit points towards i∞ of a Nevanlinna function q are studied. Given a nonempty, closed, and connected subset L of ¯C+, a Hamiltonian H is constructed explicitly such that the radial and outer angular cluster sets towards i∞ of the Weyl coefficient qH are both equal to L. The method is based on a study of the continuous group action of rescaling operators on the set of all Hamiltonians.
This work was supported by the project P 30715–N35 of the Austrian Science Fund.
The second author was supported by the joint project I 4600 of the Austrian Science Fund (FWF) and the Russian Foundation of Basic Research (RFBR).
Citation:
R. Pruckner, H. Woracek, “Limit behavior of Weyl coefficients”, Algebra i Analiz, 33:5 (2021), 153–175; St. Petersburg Math. J., 33:5 (2022), 849–865