Numerical Approximation of Exact Controls for Waves

This book is devoted to fully developing and comparingthe two main approaches to the numerical approximation of controls for wave propagation phenomena: the continuous and the discrete.This is accomplishedin the abstract functional setting of conservative semigroups.The main results of the work unify, to a large extent, these twoapproaches, which yieldsimilaralgorithms and convergence rates. The discrete approach, however, givesnot only efficient numerical approximations of the continuous controls, but also ensures some partial controllability propertiesof the finite-dimensional approximated dynamics. Moreover, it hastheadvantage of leading to iterative approximation processes that converge without a limiting threshold in the number of iterations. Such a threshold, which is hard to compute and estimate in practice, is a drawback of the methods emanating from the continuous approach.To complement this theory, the book provides convergence results for the discrete wave equation when discretized using finite differences and proves the convergence of the discrete wave equation with non-homogeneous Dirichlet conditions. The first book to explore these topics in depth, "On the Numerical Approximations of Controls for Waves" has rich applications to data assimilation problems andwill be of interest to researchers who deal with wave approximations.