Comment on the "New Rotating Black Hole in Electromagnetic Fields: Cosmological Horizon without Cosmological Constant''

Abstract

In this comment we discuss some properties of the novel spacetime, recently found in [L. Ma, H. Lü, arXiv:2606.23782]. In particular, we draw attention to the background of this solution that the authors claim to be a new spacetime. We show that this is not the case because this background belongs to the special class of electrovacuum Kundt spacetimes of type D with either electric or magnetic charge. We show this by first analyzing the algebraic properties of this spacetime, and then by finding the explicit coordinate transformations. We hope that this analysis of the background allows for a better understanding of the structure of the general class of this type, namely as the Kerr-like black holes in the background generated by an accelerating electric or magnetic charge.