Mode-resolved travel-time statistics for elastic rays in three-dimensional billiards.

We consider the ray limit of propagating ultrasound waves in three-dimensional bodies made from a homogeneous, isotropic, elastic material. Using a Monte Carlo approach, we simulate the propagation and proliferation of elastic rays using realistic angle-dependent reflection coefficients, taking into account mode conversion and ray splitting. For a few simple geometries, we analyze the long-time equilibrium distribution, focusing on the energy ratio between compressional and shear waves.