  We study the effect that the ferromagnetic order has on the electrical
properties of Diluted Magnetic Semiconductors. We analyze the temperature
dependence of the dielectric constant and of the resistivity of
Ga$_{1-x}$Mn$_x$As. In our treatment the electronic structure of the
semiconductor is described by a six band Kohn-Luttinger Hamiltonian, the
thermal fluctuations of the Mn magnetic moments are treated in the mean field
approximation, the carrier-carrier interaction within the random phase
approximation, and the transport properties using the relaxation time
approximation. We find that the Thomas-Fermi length changes near 8% when going
from the ferromagnetic to the paramagnetic phase. We also find, in good
agreement with the experiments, that the resistivity changes near 20% when
going from zero to the Curie temperature. We explain this change in the
resistivity in terms of the variation of the Fermi surface and the transport
scattering time when going from the ferromagnetic phase to the paramagnetic
phase.
