Spin dependence of the antinucleon-nucleon interaction

The status of our present knowledge on the antinucleon-nucleon interaction at low and medium energies is discussed. Special emphasis is put on aspects related to its spin dependence which are relevant for experiments planned by the PAX collaboration. Predictions for the spin-dependent antiproton-proton cross sections sigma_1 and sigma_2 are presented, utilizing antinucleon-nucleon potential models developed by the Juelich group, and compared to results based on the amplitudes of the Nijmegen partial-wave analysis.