Scattering fidelity in elastodynamics. II. Further experimental results

The agreement of past measurements of elastodynamic scattering fidelity with predictions based on random matrix theory, even in bodies with ostensibly regular ray dynamics, has motivated further measurements with a precision capable of detecting fine deviations. Two aluminum blocks are studied, one rectangular, one irregular. As previously, it is found that fidelity decays more slowly in the irregular object. It is further shown that the time dependence of that decay corresponds well with predictions based on random matrix theory and the Gaussian orthogonal ensemble and that predictions based on Poissonian model statistics do not correspond. In some cases deviations from theory are seen that are consistent with partially broken reflection symmetries and inhomogeneous dissipation.