Kinetic equations for ultrarelativistic particles in a Robertson-Walker
  Universe and isotropization of relict radiation by gravitational interactions
  Kinetic equations for ultrarelativistic particles with due account of
gravitational interactions with massive particles in the Robertson-Walker
universe are obtained. On the basis of an exact solution of the kinetic
equations thus obtained, a conclusion is made as to the high degree of the
uniformity of the relict radiation on scales with are less than $10'$.
