Almost global existence for solutions of a nonlinear fourth order hyperbolic equation
The long time existence of the solutions of the Cauchy problem for a class of nonlinear fourth-order hyperbolic equations is studied. The principal part of the equations is given by the composition of two wave operators with different propagation speeds. Almost global existence of solutions is shown.
composition of two wave operators with different prolongation speeds
scientific article; zbMATH DE number 1052942