  We theoretically study the electrical conductivity in a one-dimensional
helimagnet whose spin texture changes from helimagnetic to conical magnetic,
and to forced ferromagnetic state while increasing the magnetic field along the
helical axis. We find that the conductivity in the helimagnetic state at zero
field depends on the electron filling and the coefficient of the spin-charge
coupling. We also find that the conductivity in the conical magnetic state
changes nonlinearly to the applied field, and the magnetoresistance becomes
negative and positive depending on the model parameters.
