title: Comment on "Vacuum electron acceleration by coherent dipole radiation".
abstract: Troha et al. [Phys. Rev. E 60, 926 (1999)] put forward a generalized Lawson-Woodward theorem in the study of laser accelerations. We point out that one of the assumptions used in their proof does not stand on a solid physical ground and that it is possible for electrons to obtain net energy gains from a plane-wave laser pulse in vacuum even if the radiation reaction effects are neglected.
authors.forename: J X
authors.initials: JX
authors.lastname: Wang
authors.forename: W
authors.initials: W
authors.lastname: Scheid
authors.forename: M
authors.initials: M
authors.lastname: Hoelss
authors.forename: Y K
authors.initials: YK
authors.lastname: Ho