  We investigate, within the framework of linear elasticity theory, edge
Rayleigh waves of a two-dimensional elastic solid with broken time-reversal and
parity symmetries due to a Berry term. As our prime example, we study the
elastic edge wave traveling along the boundary of a two-dimensional skyrmion
lattice hosted inside a thin-film chiral magnet. We find that the direction of
propagation of the Rayleigh modes is determined not only by the chirality of
the thin-film, but also by the Poisson ratio of the crystal. We discover three
qualitatively different regions distinguished by the chirality of the
low-frequency edge waves, and study their properties. To illustrate the
Rayleigh edge waves in real time, we have carried out finite-difference
simulations of the model. Apart from skyrmion crystals, our results are also
applicable to edge waves of gyroelastic media and screened Wigner crystals in
magnetic fields. Our work opens a pathway towards controlled manipulation of
elastic signals along boundaries of crystals with broken time-reversal
symmetry.
