Greybody radiation of scalar and Dirac perturbations of NUT black holes

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 Schrodinger 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.