36 citations · 83 across the 11 of their papers we have counts for
Showing 2026Show all
2 papers · 1 filter
math.CV2026
Real rational Herglotz-Nevanlinna functions in two variables and a class of extremals
Ludvig Fagrell, Annemarie Luger
We first revisit the Nevanlinna condition for representing measures of Herglotz-Nevanlinna functions in two variables and give a general operator-theoretic criterion for extremalit…
math.SP2026
On eigenvalues of self-adjoint extensions for defect larger than one
Annemarie Luger, Jakob Reiffenstein
Self-adjoint extensions of a symmetric operator are parametrised by Krein's formula, in which the -function interacts with another analytic function (the parameter). We obtain a…