TY - JOUR A1 - Keller, Matthias A1 - Pinchover, Yehuda A1 - Pogorzelski, Felix T1 - Criticality theory for Schrödinger operators on graphs JF - Journal of spectral theory N2 - We study Schrodinger operators given by positive quadratic forms on infinite graphs. From there, we develop a criticality theory for Schrodinger operators on general weighted graphs. KW - green function KW - ground state KW - positive solutions KW - discrete Schrodinger KW - operators KW - weighted graphs Y1 - 2019 U6 - https://doi.org/10.4171/JST/286 SN - 1664-039X SN - 1664-0403 VL - 10 IS - 1 SP - 73 EP - 114 PB - European Mathematical Society CY - Zürich ER - TY - JOUR A1 - Beckus, Siegfried A1 - Pinchover, Yehuda T1 - Shnol-type theorem for the Agmon ground state JF - Journal of spectral theory N2 - LetH be a Schrodinger operator defined on a noncompact Riemannianmanifold Omega, and let W is an element of L-infinity (Omega; R). Suppose that the operator H + W is critical in Omega, and let phi be the corresponding Agmon ground state. We prove that if u is a generalized eigenfunction ofH satisfying vertical bar u vertical bar <= C-phi in Omega for some constant C > 0, then the corresponding eigenvalue is in the spectrum of H. The conclusion also holds true if for some K is an element of Omega the operator H admits a positive solution in (Omega) over bar = Omega \ K, and vertical bar u vertical bar <= C psi in (Omega) over bar for some constant C > 0, where psi is a positive solution of minimal growth in a neighborhood of infinity in Omega. Under natural assumptions, this result holds also in the context of infinite graphs, and Dirichlet forms. KW - Shnol theorem KW - Caccioppoli inequality KW - Schrodinger operators KW - generalized eigenfunction KW - ground state KW - positive solutions KW - weighted KW - graphs Y1 - 2020 U6 - https://doi.org/10.4171/JST/296 SN - 1664-039X SN - 1664-0403 VL - 10 IS - 2 SP - 355 EP - 377 PB - EMS Publishing House CY - Zürich ER -