Anisotropy: High energy cosmic rays and the thermal background radiation

The motion of a large (100 Mpc radius) volume of local matter with respect to the frame in which the thermal cosmic background radiation (CBR) appears isotropic is shown to produce a contribution to anisotropy in the arrival directions of the highest energy (>10¹⁹ eV) cosmic rays. The magnitude of the effect predicted is 1%, below that currently observed and below the sensitivity of present experiments.