Kerr-Schild Photonlike Metric Solutions

Abstract

The charged and spinning lightlike solutions are obtained in the Kerr-Schild formalism. In particular, one of them may be considered as an ultrarelativistic boost of the Kerr-Newman solution along the direction of angular momentum. The Kerr singular ring disappears, however, there remains a finite parameter $a$ which determines spin by the Kerr relation $J=ma$. By $J=\hbar$, the parameter $a$ is de Broglie wavelength of the corresponding photon. Electromagnetic field is aligned to the Kerr null congruence. Some of the presented solutions contain singular beam pulse (pp-strings) like the considered recently `gyratons'.