A Discrete Algorithm for General Weakly Hyperbolic Systems

Abstract: This paper studies the Cauchy problem for variable coefficient weakly hyperbolic first order systems of partial differential operators. The hyperbolicity assumption is that for each $t, x$ the principal symbol is hyperbolic. No hypothesis is imposed on lower order terms. For coefficients and Cauchy data sufficiently Gevrey regular the Cauchy problem has a unique sufficiently Gevrey regular solution. We prove stability and error estimates for the spectral Crank-Nicholson scheme. Approximate solutions can be computed with accuracy $epsilon$ in the supremum norm with cost growing at most polynomially in $epsilon^{-1}$. The proofs use the symmetrizers from [2].