TY - JOUR A1 - Klein, Markus A1 - Rosenberger, Elke T1 - Agmon estimates for the difference of exact and approximate Dirichlet eigenfunctions for difference operators JF - Asymptotic analysis N2 - We analyze a general class of difference operators H-epsilon = T-epsilon + V-epsilon on l(2)(((epsilon)Z)(d)), where V-epsilon is a multi-well potential and epsilon is a small parameter. We construct approximate eigenfunctions in neighbourhoods of the different wells and give weighted l(2)-estimates for the difference of these and the exact eigenfunctions of the associated Dirichlet-operators. Y1 - 2016 U6 - https://doi.org/10.3233/ASY-151343 SN - 0921-7134 SN - 1875-8576 VL - 97 SP - 61 EP - 89 PB - IOS Press CY - Amsterdam ER - TY - INPR A1 - Klein, Markus A1 - Rosenberger, Elke T1 - Tunneling for a class of difference operators N2 - We analyze a general class of difference operators containing a multi-well potential and a small parameter. We decouple the wells by introducing certain Dirichlet operators on regions containing only one potential well, and we treat the eigenvalue problem as a small perturbation of these comparison problems. We describe tunneling by a certain interaction matrix similar to the analysis for the Schrödinger operator, and estimate the remainder, which is exponentially small and roughly quadratic compared with the interaction matrix. T3 - Preprints des Instituts für Mathematik der Universität Potsdam - 1 (2012) 5 KW - semi-classical difference operator KW - tunneling KW - interaction matrix Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-56989 ER -