Stationary Charged Scalar Clouds around Black Holes in String Theory

TL;DR

This paper demonstrates that Kerr-Sen black holes and certain string theory black holes can support stationary charged scalar clouds, extending previous findings from Kerr-Newman black holes to string-theoretic backgrounds.

Contribution

It shows the existence of stationary charged scalar clouds around Kerr-Sen and Gibbons-Maeda-Garfinkle-Horowitz-Strominger black holes, linking black hole solutions in string theory to scalar field configurations.

Findings

Kerr-Sen black holes support stationary charged scalar clouds.

Stationary scalar clouds also exist around Gibbons-Maeda-Garfield-Horowitz-Strominger black holes.

The study extends scalar cloud phenomena to string theory black hole backgrounds.

Abstract

It was reported that Kerr-Newman black holes can support linear charged scalar fields in their exterior regions. These stationary massive charged scalar fields can form bound states, which are called stationary scalar clouds. In this paper, we show that Kerr-Sen black holes can also support stationary massive charged scalar clouds by matching the near- and far-region solutions of the radial part of the Klein-Gordon wave equation. We also review stationary scalar clouds within the background of static electrically charged black hole solutions in the low-energy limit of heterotic string field theory, namely, the Gibbons-Maeda-Garfinkle-Horowitz-Strominger black holes.