An alternating direction Galerkin method for a class of second-order hyperbolic equations in two space variables

A new alternating-direction implicit (ADI) Galerkin method is devised and analyzed for solving a certain class of second-order hyperbolic initial-boundary value problems in two space variables. This class includes the wave equation in Cartesian coordinates, polar coordinates, and cylindrical coordinates with radial symmetry. Optimal a priori $H_0^1 $ and $L^2 $-error estimates are derived.