4D Einstein-Gauss-Bonnet gravity: Massless particles and absorption of planar spin-0 waves

TL;DR

This paper studies how massless scalar waves are absorbed by black holes in a new 4D Einstein-Gauss-Bonnet gravity theory, revealing the influence of the Gauss-Bonnet coupling on absorption properties.

Contribution

It provides the first detailed analysis of scalar wave absorption in 4D Einstein-Gauss-Bonnet black holes, highlighting the dependence on the Gauss-Bonnet coupling constant.

Findings

Absorption cross section depends on the Gauss-Bonnet coupling constant.

Numerical results agree with low- and high-frequency approximations.

Sinc approximation accurately models the absorption cross section.

Abstract

We investigate the absorption cross section of planar scalar massless waves impinging on spherically symmetric black holes which are solutions of the novel 4D Einstein-Gauss-Bonnet theory of gravity. Besides the mass of the black hole, the solution depends also on the Gauss-Bonnet constant coupling. Using the partial waves approach, we show that the absorption cross section depends on the Gauss-Bonnet coupling constant. Our numerical results present excellent agreement with the low- and high- frequency approximations, including the so-called sinc approximation.