Greybody factor for black string in dRGT massive gravity

P Boonserm,T Ngampitipan,Pitayuth Wongjun

doi:10.1140/epjc/s10052-019-6827-z

Abstract

The greybody factor from the black string in the de Rham–Gabadadze–Tolley (dRGT) massive gravity theory is investigated in this study. The dRGT massive gravity theory is one of the modified gravity theories used in explaining the current acceleration in the expansion of the universe. Through the use of cylindrical symmetry, black strings in dRGT massive gravity are shown to exist. When quantum effects are taken into account, black strings can emit thermal radiation, called Hawking radiation. The Hawking radiation at spatial infinity differs from that at the source by the so-called greybody factor. In this paper, we examine the rigorous bounds on the greybody factors from the dRGT black strings. The results show that the greybody factor crucially depends on the shape of the potential, which is characterised by the model parameters. The results agree with ones in quantum mechanics; the higher the potential, the harder it is for the waves to penetrate, and also the lower the bound for the rigorous bounds.

Highlights

When quantum effects are taken into account, black holes can emit thermal radiation called Hawking radiation [35]
We examine the rigorous bounds on the greybody factors from the de Rham–Gabadadze–Tolley (dRGT) black strings
The results show that the greybody factor crucially depends on the shape of the potential, which is characterised by the model parameters

Summary

Introduction

When quantum effects are taken into account, black holes can emit thermal radiation called Hawking radiation [35]. The quasinormal mode for the dRGT black string solution have been investigated as well [63], while the greybody factor has not been investigated yet. The rigorous bounds on the greybody factor from the dRGT black strings are examined. 6. dRGT massive gravity theory, including how the black string solution can be obtained, is roughly reviewed. By imposing static and cylindrical symmetry, a general form of the black string solution (physical metric) can be written as [61]. (13), is an exact black string solution in dRGT massive gravity which, in the limit c2 = αg and c0 = c1 = 0, naturally goes over to Lemos’ black string in GR with cosmological constant [56,57].

Horizon structure

Asymptotic dS solution

Asymptotic AdS solution

Equations of motion of the massless scalar field

The rigorous bounds on the greybody factors

Conclusion