Charge and spin response of the spin-polarized electron gas

The charge and spin response of a spin-polarized electron gas is investigated including terms beyond the random-phase approximation. We evaluate the charge response, the longitudinal and transverse spin response, and the mixed spin-charge response self-consistently in terms of the susceptibility functions of a noninteracting system. Exchange-correlation effects between electrons of spin sigma and sigma' are included following Kukkonen and Overhauser, by using spin-polarization-dependent generalized Hubbard local-field factors G(sigma)(+/-) and G(<(sigma)over bar>)(+/-) The general condition for charge-density and spin-density-wave excitations of the system is discussed.