We investigate the mass-velocity dispersion relation (MVDR) in 29 galaxy clusters HIghest X-ray FLUx Galaxy Cluster Sample (HIFLUGCS). measure spatially resolved, line-of-sight velocity profiles of these clusters, which we find to be mostly flat at large radii, reminiscent rotation curves galaxies. discover a tight empirical between baryonic mass $M_\mathrm{bar}$ and $\sigma$ member galaxies, i...

A theory is presented for the dispersion relations of the nonlinear phonon-polaritons arising when phonons are coupled to the electromagnetic waves in multilayered structures of nonlinear materials. The calculations are applied to a multilayered structure consisting of a thin film surrounded by semi-infinite bounding media where each layer may have a frequency dependent dielectric function and ...