160 1994 Johan Walden johan@tdb.uu.se Spectral Analysis of the Differentiation Operator in Wavelet Bases Abstract We analyse how to use wavelets for solving hyperbolic partial differential equations. The approach is to use wavelets to get a sparse representation of the solution of the problem. The problem is studied on a periodic domain, with periodized wavelets. The order conditions for the differential operator d/dx in wavelet space are analysed. An algorithm for finding the eigenvalue function of the differential operator is presented, and general conditions that ensure a "nicely behaving" eigenvalue function are derived.