Absorption and scattering of massless scalar wave from Regular Black Holes

TL;DR

This study numerically examines how regular black holes scatter and absorb massless scalar waves, revealing parameter-dependent effects on cross sections and similarities with null geodesic behaviors at high frequencies.

Contribution

It provides new numerical insights into scalar wave scattering and absorption by regular black holes, highlighting differences from Schwarzschild black holes and analyzing high-frequency behaviors.

Findings

Absorption cross section decreases with larger parameters.

Scattering cross section is enhanced compared to Schwarzschild black holes.

High-frequency geodesic behaviors align with geometrical optics predictions.

Abstract

In this work, we numerically investigate the scattering and absorption cross section of the massless scalar field from some well-known regular black holes by using the partial wave approach. Our computational results indicate that the larger the parameters, the lower the associated total absorption cross section maxima. When compared to the Schwarzschild black hole, the scattering cross section is enhanced in some regular black hole spacetimes, meanwhile the scattering width is narrow in the forward orientation. Moreover, it is found that the null geodesics of the critical impact parameter and the geometrical optical value in the high frequency regime have similar changing behavior.