We give some theorems on continuity and differentiability with respect to (h,t) of the solution of a second order evolution problem with parameter . Our main tool is the theory of strongly continuous cosine families of linear operators in Banach spaces.
The spectral structure of the infinitesimal generator of a strongly continuous cosine function of linear bounded operators is investigated, under assumptions on the almost periodic behaviour of applications generated, in various ways, by C. Moreover, a first approach is presented to the analysis of connection between cosine functions and dynamical systems.
We extend some recent results for regularized semigroups to strongly continuous n-times integrated C-cosine operator functions. Several equivalent conditions for the existence and uniqueness of solutions of (ACP) are also presented.