“…When considering numerical discretization schemes for wave equations, it is well known that most of them do not preserve the uniform (with respect to the mesh-size h) decay property of the solutions of the continuous wave equation (1.2). Indeed, as remarked in [24,25] (see, also, [4,17,27,28]), due to the existence of high frequency spurious solutions whose (group) velocity of propagation is of the order of h, the energy of the discrete solution (u h ,u h ) does not have a uniform exponential decay. This means that the discrete energy of solutions defined by E h (t) = 1 2 (u h (t),u h (t))…”