Abstract. The present paper is devoted to the study of resonances for one-dimensional quantum systems with a potential that is the restriction to some large box of an ergodic potential. For discrete models both on a half-line and on the whole line, we study the distributions of the resonances in the limit when the size of the box where the potential does not vanish goes to infinity. For periodic and random potentials, we analyze how the spectral theory of the limit operator influences the distribution of the resonances.Résumé. Dans cet article, nousétudions les résonances d'un système unidimensionnel plongé dans un potentiel qui est la restrictionà un grand intervalle d'un potentiel ergodique. Pour des modèles discrets sur la droite et la demie droite, nousétudions la distribution des résonances dans la limite de la taille de boîte infinie. Pour des potentiels périodiques et aléatoires, nous analysons l'influence de la théorie spectrale de l'opérateur limite sur la distribution des résonances.
IntroductionConsider V : Z → R a bounded potential and, on ℓ 2 (Z), the Schrödinger operator H = −∆ + V defined by (Hu)(n) = u(n + 1) + u(n − 1) + V (n)u(n), ∀n ∈ Z, for u ∈ ℓ 2 (Z). The potentials V we will deal with are of two types:• V periodic;• V = V ω , the random Anderson model, i.e., the entries of the diagonal matrix V are independent identically distributed non constant random variable. The spectral theory of such models has been studied extensively (see, e.g., [19]) and it is well known that• when V is periodic, the spectrum of H is purely absolutely continuous;• when V = V ω is random, the spectrum of H is almost surely pure point, i.e., the operator only has eigenvalues; moreover, the eigenfunctions decay exponentially at infinity. Pick L ∈ N * . The main object of our study is the operator (0.1)For L large, the operator H L is a simple Hamiltonian modeling a large sample of periodic or random material in the void. It is well known in this case (see, e.g., [43]) that not only does the spectrum 2010 Mathematics Subject Classification. 47B80, 47H40, 60H25, 82B44, 35B34.