6 citations · 7 across the 7 of their papers we have counts for
7 papers
Estimating the number of eigenvalues of linear operators on Banach spaces
Michael Demuth, Franz Hanauska, Marcel Hansmann +1
Let be a bounded operator on a Banach space, and consider a perturbation , where is compact. This work is concerned with obtaining bounds on the number of eigenv…
On the distribution of the discrete spectrum of nuclearly perturbed operators in Banach spaces
Michael Demuth, Franz Hanauska
Let Z_0 be a bounded operator in a Banach space X with purely essential spectrum and K a nuclear operator in X. Using methods of complex analysis we study the discrete spectrum of…
Eigenvalues of non-selfadjoint operators: A comparison of two approaches
Michael Demuth, Marcel Hansmann, Guy Katriel
The central problem we consider is the distribution of eigenvalues of closed linear operators which are not selfadjoint, with a focus on those operators which are obtained as pertu…
On the discrete spectrum of non-selfadjoint operators
Michael Demuth, Marcel Hansmann, Guy Katriel
We prove quantitative bounds on the eigenvalues of non-selfadjoint unbounded operators obtained from selfadjoint operators by a perturbation that is relatively-Schatten. These boun…
On the distribution of eigenvalues of non-selfadjoint operators
Michael Demuth, Marcel Hansmann, Guy Katriel
We prove quantitative bounds on the eigenvalues of non-selfadjoint bounded and unbounded operators. We use the perturbation determinant to reduce the problem to one of studying the…
On finiteness of the sum of negative eigenvalues of Schroedinger operators
Michael Demuth, Guy Katriel
We prove conditions on potentials which imply that the sum of the negative eigenvalues of the Schroeodinger operator is finite. We use a method for bounding eigenvalues based on es…