2 papers
math-ph2021
Decay estimates for unitary representations with applications to continuous- and discrete-time models
S. Richard, R. Tiedra de Aldecoa
We present a new technique to obtain polynomial decay estimates for the matrix coefficients of unitary operators. Our approach, based on commutator methods, applies to nets of unit…
math-ph2019
Discrete Laplacian in a half-space with a periodic surface potential I: Resolvent expansions, scattering matrix, and wave operators
Song Ha Nguyen, Serge Richard, Rafael Tiedra de Aldecoa
We present a detailed study of the scattering system given by the Neumann Laplacian on the discrete half-space perturbed by a periodic potential at the boundary. We derive asymptot…