In this paper, we formulate an analytic expression of the greybody factor for the Kerr-Newman black hole in the presence of the quintessential field. Primarily, we analyze the profile of effective potential by transforming the radial equation of motion into standard Schr$\ddot{o}$dinger form through tortoise coordinate. The two asymptotic solutions, in the form of hypergeometric functions, are computed at distinct radial regions such as a black hole and cosmological horizons determined by the quintessence. To extend the viability over the whole radial regime, we match the analytical solutions smoothly in an intermediate region by using a semi-classical approach. We also calculate the emission rates and absorption cross-section for the massless scalar fields to elaborate on the significance of our result. It is found that the electromagnetic force together with the gravitational pull of the black hole maximizes the effective potential and consequently, decreases the emission process of scalar field particles.
In this work, we study the weak gravitational lensing in the background of Kerr-Newman black hole with quintessential dark energy. Initially, we compute the deflection angle of light by charged black hole with quintessential dark energy by utilizing the Gauss-Bnnet theorem. Firstly, we suppose the light rays on the equatorial plane in the axisymmetric spacetime. In doing so, we first find the corresponding optical metrics and then calculate the Gaussian optical curvature to utilize in Gauss-Bonnet theorem. Consequently, we calculate the deflection angle of light for rotating charged black hole…
Finding exact solutions for black-hole greybody factors is generically impractical; typically one resorts either to making semi-analytic or numerical estimates, or alternatively to deriving rigorous analytic bounds. Indeed, rigorous bounds have already been established for the greybody factors of Schwarzschild and Riessner-Nordstrom black holes, and more generally for those of arbitrary static spherically symmetric asymptotically flat black holes. Adding rotation to the problem greatly increases the level of difficulty, both for purely technical reasons (the Kerr or Kerr-Newman black holes are…
Hairy Kiselev black hole with quintessential matter: themodynamic properties, sparsity of Hawking radiation, and greybody factors
The Assam Royal Global University（阿萨姆皇家全球大学）；Universidade Federal da Paraíba（帕拉伊巴联邦大学）；Secretaria da Educação do Ceará (SEDUC)（塞阿拉州教育厅）；Echahid Cheikh Larbi Tebessi University（谢赫·拉里比·特贝西大学）
This paper is devoted to analyzing the critical phenomenon and phase transition of quintessential Kerr-Newman-anti-de Sitter black hole in the framework of Maxwell equal-area law. For this purpose, we first derive thermodynamic quantities such as Hawking temperature, entropy and angular momentum in the context of extended phase space. These quantities satisfy Smarr-Gibbs-Dehum relation in the presence of quintessence matter. We then discuss the critical behavior of thermodynamic quantities through two approaches, i.e., van der Waals-like equation of state and Maxwell equal-area law. It is foun…
We investigate the Dirac and Klein-Gordon equations, as well as greybody radiation, for the Hayward black hole (BH) spacetime. We first consider the Dirac equation using a null tetrad in the Newman- Penrose (NP) formalism. The equations are then separated into angular and radial parts. A pair of one-dimensional Schrödinger like wave equations with effective potentials is obtained from the radial part. In order to examine the behavior of potentials, they are plotted with respect to radial distances. Additionally, the Klein-Gordon equation is considered in the Hayward BH spacetime. At the end, w…
Quintessential dark energy with pressure $p$ and density $ρ$ is related by equation of state $p=ωρ$ with the state parameter $-1<ω<-1/3$. The cosmological dark energy influence on black hole spacetime are interesting and important. In this paper, we study the Kerr-Newman-AdS solutions of the Einstein-Maxwell equation in quintessence field around a black hole by Newman-Janis algorithm and complex computations. From the horizon structure equation, we obtain the expression between quintessence parameter $α$ and cosmological constant $Λ$ if the black hole exists two cosmological horizon $r_{q}$ an…
In this paper, we investigated the Dirac and Klein-Gordan equations, as well as the greybody factor for a Schwarzschild black hole (SBH) immersed in quintessence and associated with a cloud of strings. Primarily, we study the Dirac equation using a null tetrad in the Newman- Penrose (NP) formalism. Next, we separate the Dirac equation into radial and angular sets. Using the radial equations, we study the profile of effective potential by transforming the radial equation of motion into standard Schr% ödinger wave equations form through tortoise coordinate. Similarly, we study the Klein-Gordan e…
Rotating black hole solution surrounded by quintessential matter is recently discussed because it might be the promising solution to study the effect of dark energy in small scale of the universe. This quintessential solution is originally derived from the condition of additivity and linearity for the energy-momentum tensor. We carry out the thermodynamic properties of this solution using the Kerr/CFT correspondence for several specific quintessential equation of state parameters. A problem arises when we compute the central charge because the canonical conserved charge is needed to be calcula…
We discuss spherically symmetric exact solutions of the Einstein equations for quintessential matter surrounding a black hole, which has an additional parameter ($ω$) due to the quintessential matter, apart from the mass ($M$). In turn, we employ the Newman\(-\)Janis complex transformation to this spherical quintessence black hole solution and present a rotating counterpart that is identified, for $α=-e^2 \neq 0$ and $ω=1/3$, exactly as the Kerr\(-\)Newman black hole, and as the Kerr black hole when $α=0$. Interestingly, for a given value of parameter $ω$, there exists a critical rotation para…
In Schwarzschild's acoustic black hole (SABH) spacetime, we investigate the wave dynamics for the fermions. To this end, we first take into account the Dirac equation in the SABH by employing a null tetrad in the Newman-Penrose (NP) formalism. Then, we consider the Dirac and Rarita Schwinger equations, respectively. The field equations are reduced to sets of radial and angular equations. By using the analytical solution of the angular equation set, we decouple the radial wave equations and obtain the one-dimensional Schrödinger like wave equations with their effective potentials. The obtained …
The exact solutions of the Dirac equation that describe a massive, non-charged particle with spin-(1/2) in the curved spacetime geometry of regular Bardeen black hole surrounded by quintessence (BBHSQ) are investigated. We first derive the Dirac equation in the BBHSQ background using a null tetrad in the Newman-Penrose formalism. Afterward, we separate the Dirac equation into ordinary differential equations for the radial and angular parts. The angular equations are solved exactly in terms of standard spherical harmonics. The radial part equations are transformed into a Schrödinger like differ…
The existence of quintessential dark energy around a black hole has considerable consequences on its spacetime geometry. Hence, in this article, we explore its effect on horizons and the silhouette generated by a Kerr-Newman black hole in quintessential dark energy. Moreover, to analyze the deflection angle of light, we utilize the Gauss-Bonnet theorem. The obtained result demonstrates that, due to the dragging effect, the black hole spin elongates its shadow in the direction of the rotational axis, while increases the deflection angle. On the other hand, the black hole charge diminishing its …
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 Schrödinger wave equations together with effective potentials. Then, we discuss the potentials…
We find a charged spherically symmetric black hole solution with the existence of a cloud of strings and quintessential matter. Then we apply the Demianski-Newman-Janis algorithm to generate the rotating and twisting counterpart. The thermodynamic properties of this black hole solution are further investigated.
We obtain an exact slowly rotating Einstein-bumblebee black hole solution by solving the corresponding $rr$ and $tϕ$ components of the gravitational field equations in both cases: A, $b_μ=(0,b(r),0,0)$; B, $b_μ=(0,b(r),\mathfrak{b}(θ),0)$. Then we check the other gravitational field equations and the bumblebee field motion equations by using this solution. We find that in the case A, there exists a slowly rotating black hole solution indeed for arbitrary LV (Lorentz violation) coupling constant $\ell$; however as in the case B, there exists this slowly rotating solution if and only if the coup…
Probing Bardeen-Kiselev black hole with cosmological constant caused by Einstein equations coupled with nonlinear electrodynamics using quasinormal modes and greybody bounds
We study the greybody factor and Hawking radiation with a non-minimal derivative coupling between the scalar field and the curvature in the background of the slowly rotating Kerr-Newman black hole. Our results show that both the absorption probability and luminosity of Hawking radiation of the scalar field increase with the coupling. Moreover, we also find that for the weak coupling $η<η_c$, the absorption probability and luminosity of Hawking radiation decrease when the black hole's Hawking temperature decreases; while for stronger coupling $η>η_c$, the absorption probability and luminosity o…
We study the shadow of rotating charge black holes in the presence of quintessence. The shadow of a rotating black hole is a distorted circle and in our study, we find that the shape and size of the black hole shadow depend upon four parameters, i.e., charge $q$, spin parameter $a$, quintessential field parameter $ω_q$ and normalization factor $c$. The parameter $ω_q$ can take the value between $-1<ω_q<-1/3$ and related with pressure $p$ and density $ρ_q$ by the equation of state $p=ω_q ρ_q$. We derive the complete geodesic structure of photon near black hole using the Hamilton-Jacobi equation…
Stationary scalar clouds, quasinormal ringing, and observational signatures of (near-)extremal rotating Kalb-Ramond black holes: from the superradiant threshold to EHT bounds
Cyprus International University（塞浦路斯国际大学）；Eastern Mediterranean University（东地中海大学）
