  The dynamics of a (quasi)one-dimensional interacting atomic Bose-Einstein
condensate in a tilted optical lattice is studied in a discrete mean-field
approximation, i.e., in terms of the discrete nonlinear Schr\"odinger equation.
If the static field is varied the system shows a plethora of dynamical
phenomena. In the strong field limit we demonstrate the existence of (almost)
non-spreading states which remain localized on the lattice region populated
initially and show coherent Bloch oscillations with fractional revivals in the
momentum space (so called quantum carpets). With decreasing field, the dynamics
becomes irregular, however, still confined in configuration space. For even
weaker fields we find sub-diffusive dynamics with a wave-packet width spreading
as $t^{1/4}$.
