We study the anisotropic Kardar-Parisi-Zhang equation using nonperturbative
renormalization group methods. In contrast to a previous analysis in the
weak-coupling regime we find the strong coupling fixed point corresponding to
the isotropic rough phase to be always locally stable and unaffected by the
anisotropy even at non-integer dimensions. Apart from the well-known weak
coupling and the now well established isotropic strong coupling behavior, we
find an anisotropic strong coupling fixed point for nonlinear couplings of
opposite signs at non-integer dimensions.Comment: 18 pages, 7 figures, enlarged figures + minor changes, final versio