  We study the influence of the non-homogeneity of a magnetization field on the
behaviour of interacting electrons in a quantum dot. In particular we
investigate the magnetotransport properties when the dot is weakly coupled to
two ferromagnetic leads. We take into account the interactions in the quantum
dot non-perturbatively. For a magnetization which varies slowly on the scale of
the Fermi wave length, the non-homogeneity effect is described by a gauge
potential that can be treated perturbatively.
