Matrix methods for wave equations
arXiv:1906.00477 · doi:10.1007/s00209-005-0925-3
Abstract
In analogy to a characterisation of operator matrices generating -semigroups due to R. Nagel (\cite{[Na89]}), we give conditions on its entries in order that a operator matrix generates a cosine operator function. We apply this to systems of wave equations, to second order initial-boundary value problems, and to overdamped wave equations.