  The magnetization response of bulk ferromagnets after excitation by an
ultrashort optical pulse is calculated using a dynamical model of the
Elliott-Yafet type that includes the effects of the spin-orbit interaction in
the ab-initio ferromagnetic band structure, the electron-phonon interaction at
the level of Boltzmann scattering integrals, and dynamical changes in the
temperature of the phonon bath. Using realistic parameters for the ultrashort
optical pulse, the computed maximum magnetization quenching achievable with
electron-phonon scattering in a fixed band structure is much smaller than the
quenching observed in experiments. Heating of the phonon bath is found to not
appreciably change the magnetization dynamics on ultrashort timescales.
