Dispersive model for the dielectric permittivity -Lorentz model (particle model) A.Lna H.A.Lorentz F=-e(E+v×B), The electron in an atom can be assumed to be bound to the equilibrium position through an elastic restoring force,the equation of motion is: mi+myi+mwor =-eEo exp(-iwt), Damping force due to all inelastic processes Harmonic restoring force r =ro exp(-iwt) -eEo/m w-w(w+iy）Damping force due to all inelastic processes The electron in an atom can be assumed to be bound to the equilibrium position through an elastic restoring force, the equation of motion is: H.A.Lorentz Dispersive model for the dielectric permittivity ——Lorentz model (particle model) Harmonic restoring force