Greybody Radiation of scalar and Dirac perturbations of NUT Black Holes

TL;DR

This paper analyzes scalar and Dirac field perturbations in NUT black hole spacetime, deriving wave equations, effective potentials, and greybody factors, highlighting the influence of the NUT parameter on radiation properties.

Contribution

It provides a detailed derivation of wave equations and greybody factors for scalar and Dirac fields in NUT spacetime, including the impact of the NUT parameter.

Findings

Effective potentials are plotted as functions of radial distance.

Greybody factors are computed for both bosons and fermions.

The NUT parameter significantly influences greybody radiation.

Abstract

We consider the spinorial wave equations, namely the Dirac and the Klein-Gordon equations, and greybody radiation in the NUT black hole spacetime. To this end, we first study the Dirac equation in NUT spacetime by using a null tetrad in the Newman-Penrose (NP) formalism. Next, we separate the Dirac equation into radial and angular sets. The angular set is solved in terms of associated Legendre functions. With the radial set, we obtain the decoupled radial wave equations and derive the one-dimensional Schr\"odinger wave equations together with effective potentials. Then, we discuss the potentials by plotting them as a function of radial distance in a physically acceptable region. We also study the Klein-Gordon equation to compute the greybody factors (GFs) for both bosons and fermions. The influence of the NUT parameter on the GFs of the NUT spacetime is investigated in detail.