Time-averaged total force on a dipolar sphere in an electromagnetic field.

We establish the time-averaged total force on a subwavelength-sized particle in a time-harmonic-varying field. Our analysis is not restricted to the spatial dependence of the incident field. We discuss the addition of the radiative reaction term to the polarizability to deal correctly with the scattering force. As an illustration, we assess the degree of accuracy of several previously established polarizability models.