Local-field corrections in a Doppler-broadened gas

We introduce the thermal motion of atoms into our classical-electrodynamics simulations to study the cooperative response of a near-resonant gas to light. The simulation results for the shift of the resonance line are closer to the standard prediction from local-field corrections plus ``cooperative Lamb shift'' than we have seen either in dilute homogeneously broadened atomic samples or in cases when inhomogeneous broadening is modeled with a random distribution of resonance frequencies of stationary atoms. Inhomogeneous broadening due to the motion of the atoms may be a key factor in establishing the traditional phenomenology of local-field corrections.