5 papers
Growth of Eigenfunctions and R-limits on Graphs
Siegfried Beckus, Latif Eliaz
A characterization of the essential spectrum of Schrödinger operators on infinite graphs is derived involving the concept of -limits. This concept, whi…
Generalized eigenfunctions and eigenvalues: a unifying framework for Shnol-type theorems
Siegfried Beckus, Baptiste Devyver
Let be a generalized Schrödinger operator on a domain of a non-compact connected Riemannian manifold, and a generalized eigenfunction for : that is, satisfies the eq…
Hölder Continuity of the Spectra for Aperiodic Hamiltonians
Siegfried Beckus, Jean Bellissard, Horia Cornean
We study the spectral location of strongly pattern equivariant Hamiltonians arising through configurations on a colored lattice. Roughly speaking, two configurations are "close to…
Delone dynamical systems and spectral convergence
Siegfried Beckus, Felix Pogorzelski
In the realm of Delone sets in locally compact, second countable, Hausdorff groups, we develop a dynamical systems approach in order to study the continuity behavior of measured qu…
Shnol-type theorem for the Agmon ground state
Siegfried Beckus, Yehuda Pinchover
Let be a Schrödinger operator defined on a noncompact Riemannian manifold , and let . Suppose that the operator is critical in , and le…