2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/47543We review recent progress in calculating the twist--2 parton distribution functions at a low normalization point in the large--$N_c$ limit, where the nucleon can be described as a soliton of the effective chiral lagrangian. This field-theoretic approach preserves all general requirements on the distribution functions (positivity, normalization etc.). In particular, it allows to calculate the polarized and unpolarized antiquark distributions at the low normalization point.13 pages, LaTeX, 2 figures included using epsf. Talk given at the Workshop ``Deep Inelastic Scattering off Polarized Targets: Theory Meets Experiment'', DESY-Zeuthen, Sep. 1-5, 1997High Energy Physics - Phenomenologytext