Comment on 'Two-photon laser-assisted electron scattering on hydrogen atom'

Abstract

In connection to the paper by Kornev and Zon (2019 J. Phys. B: At. Mol. Opt. Phys. 52 075205), we would like to remind that the two-photon laser-assisted electron scattering on hydrogen atom is a subject already studied and analyzed in the literature, and we briefly present the well established situation. We wish to point out a possible limitation in the calculations performed within the perturbation theory in reference to the work by Kornev and Zon (2019 J. Phys. B: At. Mol. Opt. Phys. 52 075205) at high laser intensities and/or at very low photon energies, where the α 0| ⋅q| ≪ 1 condition is not satisfied.