13 citations · 49 across the 22 of their papers we have counts for
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math-ph2012★ 3 cited
Perturbation determinants and trace formulas for singular perturbations
Mark M. Malamud, Hagen Neidhardt
We use the boundary triplet approach to extend the classical concept of perturbation determinants to a more general setup. In particular, we examine the concept of perturbation det…
math.FA2012
Spectral theory of Schrödinger operators with infinitely many point interactions and radial positive definite functions
Mark M. Malamud, Konrad Schmüdgen
A number of results on radial positive definite functions on related to Schoenberg's integral representation theorem are obtained. They are applied to the study of…
math.FA2012
Unitary equivalence of proper extensions of a symmetric operator and the Weyl function
Seppo Hassi, Mark Malamud, Vadim Mogilevskii
Let be a densely defined simple symmetric operator in $\gH$, let $Π=\bt$ be a boundary triplet for and let $M(\cd)$ be the corresponding Weyl function. It is known that t…