ANGULAR-MOMENTUM TRANSFER BY NONRADIAL OSCILLATIONS IN MASSIVE MAIN-SEQUENCE STARS

We discuss angular momentum transfer by low-frequency non-axisymmetric oscillations in uniformly or differentially rotating massive main-sequence stars. A prograde mode, which is expected to be excited in these stars, carries angular momentum from the outer part of the convective core to the radiative envelope. The most efficient agent in this process is the Reynolds stress generated by the radial and azimuthal velocity components of the oscillation. Radiative dissipation greatly enhances the accumulation rate of angular momentum near the surface. The time-scale for the change of the angular momentum of rotation seems to be short enough to affect the angular momentum distribution during the main-sequence evolution.