  We discuss static and dynamic fluctuations of domain walls separating areas
of constant but different slopes in steady-state configurations of crystalline
surfaces both by an analytic treatment of the appropriate Langevin equation and
by numerical simulations. In contrast to other situations that describe the
dynamics in Ising-like systems such as models A and B, we find that the dynamic
exponent z=2 that governs the domain wall relaxation function is not equal to
the inverse of the exponent n=1/4 that describes the coarsening process that
leads to the steady state.
