On spontaneous photon emission in collapse models

We reanalyze the problem of spontaneous photon emission in collapse models. We show that the extra term found by Bassi and Duerr is present for non-white (colored) noise, but its coefficient is proportional to the zero frequency Fourier component of the noise. This leads one to suspect that the extra term is an artifact. When the calculation is repeated with the final electron in a wave packet and with the noise confined to a bounded region, the extra term vanishes in the limit of continuum state normalization. The result obtained by Fu and by Adler and Ramazanoglu from application of the Golden Rule is then recovered.