Connections between the shadow radius and the quasinormal modes of Kerr-Sen black hole

TL;DR

This paper explores the relationship between shadow radius and quasinormal modes of Kerr-Sen black holes, deriving formulas and analyzing energy emission rates, confirming previous results in the eikonal limit.

Contribution

It provides a new expression linking shadow radius and quasinormal modes for Kerr-Sen black holes, extending previous work and analyzing energy emission characteristics.

Findings

Derived a formula connecting shadow radius and quasinormal modes.

Confirmed the formula matches previous results in the eikonal limit.

Found the peak energy emissivity decreases with increasing charge parameter.

Abstract

The correspondence between the shadow radius and the quasi-normal modes of the Kerr-Sen black hole is studied. By using the equation of the shadow radius of the Kerr-Sen black hole and the angular separation constant of the quasi-normal modes, the expression of the real part of quasi-normal modes related to the shadow radius is obtained. We found that in the eikonal limit, our formula coincides with the previous result. Moreover, we also calculate the energy emission rate of the Kerr-Sen black hole, it turns out that the peak energy emissivity is inversely correlated with the charge parameter.