  We study the propagation of anisotropic sound and shock waves in dipolar
Bose-Einstein condensate in three dimensions (3D) as well as in quasi-two (2D,
disk shape) and quasi-one (1D, cigar shape) dimensions using the mean-field
approach. In 3D, the propagation of sound and shock waves are distinct in
directions parallel and perpendicular to dipole axis with the appearance of
instability above a critical value corresponding to attraction. Similar
instability appears in 1D and not in 2D. The numerical anisotropic Mach angle
agrees with theoretical prediction. The numerical sound velocity in all cases
agrees with that calculated from Bogoliubov theory. A movie of the anisotropic
wave propagation in a dipolar condensate is made available as supplementary
material.
