This is the abstract of the paper "A characteristic equation for non--autonomous partial functional differential equations" by Gabriele Guehring and Frank Raebiger and Roland Schnaubelt. For the whole paper send the command get evolve-l 00-00035 to: "listserv@uni-karlsruhe.de". Instead you may get the paper at "http://ma1serv.mathematik.uni-karlsruhe.de/evolve-l/index.html" too. Abstract: We characterize the exponential dichotomy of non--autonomous partial functional differential equations by means of a spectral condition extending known characteristic equations for the autonomous or time periodic case. From this we deduce robustness results. We further study the almost periodicity of solutions to the inhomogeneous equation. Our approach is based on the spectral theory of evolution semigroups. ------------------ http://www.uni-karlsruhe.de/~listserv/ -------------------