# İzzet Sakallı (I.Sakalli)Eastern Mediterranean University · Department of Physics

İzzet Sakallı (I.Sakalli)

Professor

## About

209

Publications

40,563

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3,204

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Introduction

İzzet Sakallı (I.Sakalli) currently works at the Department of Physics, Eastern Mediterranean University. İzzet does research in Theoretical Physics and Mathematical Physics. His current project is 'Quasinormal Modes and Black Hole Quantization'

Additional affiliations

September 1998 - present

## Publications

Publications (209)

Charged massive scalar fields are studied in the gravitational, electromagnetic, dilaton, and axion fields of rotating linear dilaton black holes. In this geometry, we separate the covariant Klein--Gordon equation into radial and angular parts and obtain the exact solutions of both the equations in terms of the confluent Heun functions. Using the r...

In this work, we consider a class of hyperscaling violating Lifshitz-like black branes with metric scaling components \(z=2\) and \(\theta =-1\) whose corresponding holographic model can be treated as a non-relativistic fluid exhibiting Lifshitz-type symmetry. Having performed analytical calculations via the Klein–Gordon equation and the linear res...

In the framework of the Lorentz symmetry breaking (LSB), we investigate the quasinormal modes (QNMs) and the greybody factors (GFs) of the Kerr-like black hole spacetime obtained from the bumblebee gravity model. In particular, we analyze the scalar and fermionic perturbations of the black hole within the framework of both semi-analytic WKB method...

We give a pedagogical introduction to black holes (BHs) greybody factors (GFs) and quasinormal modes (QNMs) and share the recent developments on those subjects. To this end, we present some particular analytical and approximation techniques for the computations of the GFs and QNMs. We first review the gravitational GFs and show how they are analyti...

In this paper, we explore the Weak Gravity Conjecture (WGC) within the context of photon spheres in charged black holes, framed by Perfect Fluid in Rastall Theory. We aim to validate the WGC by identifying the extremality states of these black holes. We highlight the interplay between quantum dynamics and gravitational forces, opening new avenues i...

In this paper, we study the thermodynamic properties and stability of static charged BTZ black holes with the inclusion of higher-order quantum corrections. The corrections to the entropy, mass, and Helmholtz free energy are derived, revealing the intricate interplay between quantum effects and classical gravitational forces in the context of black...

This article investigates the geodesic structure and deflection angle of charged black holes in the presence of a nonzero vacuum expectation value background of the Kalb–Ramond field. Topics explored include null and timelike geodesics, energy extraction by collisions, and the motion of charged particles. The photon sphere radius is calculated and...

This article investigates the geodesic structure and deflection angle of charged black holes in the presence of a nonzero vacuum expectation value background of the Kalb-Ramond field. Topics explored include null and timelike geodesics, energy extraction by collisions, and the motion of charged particles. The photon sphere radius is calculated and...

In this paper, we consider an $\alpha^{\prime}$ corrected Reissner-Nordstr\"{o}m AdS black hole to study thermodynamics. We study the $P-V$ criticality and thermodynamical stability of the black hole. We obtained a first-order phase transition, which may be interpreted as the large/small black hole phase transition. Therefore, we obtained a van der...

We discuss the corrected thermodynamics and naked singularity structure of the topological static spherically symmetric solution in F(R,G) - gravity coupled with Born-Infeld—like nonlinear electrodynamics. Solutions admitting black holes with constant topological Euler density is analyzed in view of various thermodynamical variables. The inclusion...

In this paper, we consider a charged BTZ black hole in asymptotically AdS spacetime of massive gravity to study the effect of the thermal fluctuations on the black hole thermodynamics. We consider the Einstein–Born–Infeld solution and investigate critical points and stability. We also compare the results with the case of Einstein–Maxwell solutions....

The unification of quantum mechanics and general relativity has long been elusive. Only recently have empirical predictions of various possible theories of quantum gravity been put to test. The dawn of multi-messenger high-energy astrophysics has been tremendously beneficial, as it allows us to study particles with
much higher energies and travelli...

In this article, we study the Hawking radiation of the Schwarzschild black hole within the bumblebee gravity model (SBHBGM). Considering classical approaches involving Killing vectors and the standard Hamilton-Jacobi method, the Hawking radiation of SBHBGM is computed. The Painlevé-Gullstrand, ingoing Eddington-Finkelstein, and Kruskal-Szekeres coo...

In this paper, we will go beyond equilibrium description to properly investigate the evaporation of a
Reissner-Nordstr"{o}m black hole. Thus, we will explicitly apply techniques of non-equilibrium quantum thermodynamics to this black hole. As the non-equilibrium effects would become important at the quantum scale, we will incorporate the quantum g...

This article investigates the influence of the Generalized Uncertainty Principle (GUP) on the emission of Hawking quanta in a rotating linear dilaton black hole spacetime. The study proposes a GUP-reinforced black hole thermal emission model that takes into account the quantum tunneling process with GUP effects. The result obtained for the correcte...

In this article, we study the Hawking radiation of the Schwarzschild black hole within the bumblebee gravity model (SBHBGM). Considering classical approaches involving Killing vectors and the standard Hamilton-Jacobi method, the Hawking radiation of SBHBGM is computed. The Painlevé-Gullstrand, ingoing Eddington-Finkelstein, and Kruskal-Szekeres coo...

We study the greybody factors, quasinormal modes, and shadow of the higher dimensional de-Sitter (dS)/anti de-Sitter (AdS) black hole spacetimes derived from the Einstein-bumblebee gravity theory within the Lorentz symmetry breaking (LSB) framework. We specifically apply the semi-analytical WKB method and the time domain approach to study the scala...

In this paper, we study a particular type of inflation by using non-local Friedman equations that are derived from the zero levels of string field theory and express a tachy-onic action. Then, we challenge it by further refining de Sitter (dS) swampland conjecture (FRdSSC) monitoring. Therefore , we investigate some quantities, such as potential an...

The ability of bumblebee gravity models to explain dark energy, which is the phenomenon responsible for the universe's observed accelerated expansion, is one of their most significant applications. An effect that causes faster expansion can be linked to how much the Lorentz symmetry of our universe is violated. Moreover, since we do not know what g...

This work is dedicated to the investigation of the superradiant stability of a rotating black hole derived from the nonlinear Maxwell theory of gravity, f (R). The evaluation of stability and instability in this study will be based on the absence and presence of the magnetic field, respectively, when the magnetic field constant is c 4 = 0 and c 4 =...

In this paper, we study a particular type of inflation by using non-local Friedman equations that are somehow derived from the zero levels of string field theory and express a tachyonic action. Then, we challenge it by further refining de Sitter (dS) swampland conjecture (FRdSSC) monitoring. Therefore, we investigate some quantities, such as potent...

It is known that entropy of black hole gets correction at quantum level. Universally, these corrections are logarithmic and exponential in nature. We analyze the impacts of these quantum corrections on thermodynamics of Born-Infeld BTZ black hole in massive gravity by considering both such kinds of correction. We do comparative analysis of correcte...

In Schwarzschild 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...

Black hole’s quasinormal frequencies are basically the complex numbers which provide information about the relaxation of perturbations and depend on the characteristics of the spacetime and types of perturbations. In this paper, we evaluate the spectrum of the quasinormal modes of Hayward black hole in Einstein–Gauss–Bonnet gravity, Hayward black h...

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...

The research of superradiant instability in the realm of quantum gravity is a well-known topic, with many physicists and astronomers studying the potential impact it can have on gravitational waves, the structure of the universe, and spacetime itself. In this work, we investigate the superradiant (in)stability of a rotating black hole obtained from...

In this paper, we will analyze the effects of $\alpha^{\prime} $ corrections on the behavior of a Reissner-Nordstr\"{o}m black hole. We will calculate the effects of such corrections on the thermodynamics and thermodynamic stability of such a black hole. We will also derived a novel $\alpha^{\prime}$-corrected first law. We will investigate the eff...

It is known that entropy of black hole gets correction at quantum level. Universally, these corrections are logarithmic and exponential in nature. We analyze the impacts of these quantum corrections on thermodynamics of Born-Infeld BTZ black hole in massive gravity by considering both such kinds of correction. We do comparative analysis of correcte...

We discuss the corrected thermodynamics and naked singularity structure of the topological static spherically symmetric solution in $\mathcal{F}(R,\mathcal{G})$ - gravity coupled with Born-Infeld - like nonlinear electrodynamics. Solutions admitting black holes with constant topological Euler density is analyzed in view of various thermodynamical v...

In this paper, we consider non-perturbative quantum correction which appears as exponential term in the black hole entropy. We study consequence thermodynamics of the Ho\v{r}ava-Lifshitz black hole at quantum scales. We consider two cases of Kehagius-Sfetsos and Lu-Mei-Pop solutions and investigate black hole stability. We find that non-perturbativ...

In this paper, we consider non-perturbative quantum correction which appears as exponential term in the black hole entropy. We study consequence thermodynamics of the Hořava-Lifshitz black hole at quantum scales. We consider two cases of Kehagius-Sfetsos and Lu-Mei-Pop solutions and investigate black hole stability. We find that non-perturbative qu...

We study the greybody factors, quasinormal modes, and shadow of the higher dimensional de-Sitter (dS)/ anti de-Sitter (AdS) black hole spacetimes derived from the Einstein-bumblebee gravity theory within the Lorentz symmetry breaking (LSB) framework. We specifically apply the semi-analytical WKB method and the time domain approach to study the scal...

The method of Rindler and Ishak enables one to study how light is bent in the vicinity of a non-rotating and spherically symmetric gravitational lens. This method mainly aims to investigate the role of cosmological constant in the consequent path. In this paper, we use the extension of Rindler-Ishak method (RIM) in order to evaluate the deflection...

In this paper, we construct a new charged AdS black hole with modified cosmic Chaplygin gas (MCCG). In comparison to the previous model (modified Chaplygin AdS black hole) that existed in the literature, we now have two new parameters: the cosmic parameter and the black hole’s electric charge. We examine the asymptotically charged AdS black hole th...

We give a pedagogical introduction to black holes (BHs) greybody factors (GFs) and quasinormal modes (QNMs) and share the recent developments on those subjects. In this study, our primary focus will be on the bosonic and fermionic GFs and QNMs of various BH and brane geometries and reveal the fingerprints of the invisibles with the radiation spectr...

The paper studies the spinorial wave equations, namely the Dirac and the Klein Gordon equations, as well as the greybody radiations and quasinormal modes (QNMs) of the charged Taub NUT black hole (CTNBH). To obtain fermionic greybody factors (GFs) and QNMs, we study the charged fermions by employing the Dirac equation. To this end, we use a null te...

In our recent study Ref. [1]: Eur. Phys. J. C 81, 501 (2021) , the main goal was to reveal the Lorentz symmetry breaking (LSB) effect in the rotating black holes via the greybody factor and quasinormal mode analyzes. Ding et al. [2] Kerr-like black hole solution of the bumblebee gravity model used in our paper [1] has unquestionably proven by Maluf...

In this paper, we consider two brane-world black holes whose solutions are obtained via a confining potential and study their thermodynamical properties. The modified entropies by taking account of the generalized uncertainty principle (GUP) are obtained. We also determine the scalar effective potentials in order to compute the greybody factors of...

We study the quasinormal modes of scalar waves of the black strings of the asymptotically AdS spacetime. Resonance modes of the quasinormal modes are computed analytically. In the following section, we present how the mass transfer of black strings in the semi-classical limit is linked to their highly damped oscillation frequencies. The Bohr–Sommer...

In this paper, we consider two brane-world black holes whose solutions are obtained via a confining potential and study their thermodynamical properties. The modified entropies by taking account of the generalized uncertainty principle (GUP) are obtained. We also derive the effective potentials of the scalar particles and compute the greybody facto...

In this paper, we study the GUP (Generalized Uncertainty Principle) modified Hawking radiation of rotating polytropic black hole given in the Boyer-Lindquist coordinates. To this end, the GUP modified Klein-Gordon equation is applied for investigating the quantum tunneling of scalar particles from the polytropic black hole. After reducing the obtai...

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...

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...

In this paper, we study the GUP (Generalized Uncertainty Principle) modified Hawking radiation of rotating polytropic black hole given in the Boyer-Lindquist coordinates. To this end, the GUP modified Klein-Gordon equation is applied for investigating the quantum tunneling of scalar particles from the polytropic black hole. After reducing the obtai...

In this paper, we show how the quasinormal modes (QNMs) arise from the perturbations of massive scalar fields propagating in the curved background by using the artificial neural networks. To this end, we architect a special algorithm for the feedforward neural network method (FNNM) to compute the QNMs complying with the certain types of boundary co...

In this paper we study the effects of the cosmological constant and rotation on the deflectionangle of null geodesics in the equatorial plane of Kerr-Newman anti de Sitter (KNAdS) spacetime.To this end, we employ the extension of Rindler-Ishak method to compute the gravitational lensingeffect. Gravitational lensing phenomena based on diffraction of...

In the framework of the Lorentz symmetry breaking (LSB), we investigate the quasinormal modes (QNMs) and the greybody factors (GFs) of the Kerr-like black hole spacetime obtained from the bumblebee gravity model. In particular, we analyze the scalar and fermionic perturbations of the black hole within the framework of both semi-analytic WKB method...

We study charged massless fermionic perturbations in the background of $4$-dimensional linear dilaton black holes in Einstein-Maxwell-dilaton theory with double Liouville-type potentials. We present the analytical fermionic quasinormal modes, whose Dirac equations are solved in terms of hypergeometric functions. We also discuss the stability of the...

In this paper, we use a new asymptotically flat and spherically symmetric solution in the generalized Einstein-Cartan-Kibble-Sciama (ECKS) theory of gravity to study the weak gravitational lensing and its shadow cast. To this end, we first compute the weak deflection angle of generalized ECKS black hole using the Gauss-Bonnet theorem in plasma medi...

Black hole's quasinormal frequencies are basically the complex numbers which provide information about the relaxation of perturbations and depend on the characteristics of the spacetime and types of perturbations. In this paper, we evaluate the quasinormal modes of Hayward black hole in Einstein Gauss-Bonnet gravity, Hayward black hole in anti-de S...

We study light rays in the static and spherically symmetric gravitational field of the null aether theory (NAT). To this end, we employ the Gauss-Bonnet theorem to compute the deflection angle formed by a NAT black hole in the weak limit approximation. Using the optical metrics of the NAT black hole, we first obtain the Gaussian curvature and then...

In the context of the dRGT massive gravity coupled with nonlinear electrodynamics, we present new dRGT black hole solutions. Together with the thermodynamical properties of the solutions, we study the greybody factor of the corresponding black hole solution. To this end, we compute the rigorous bound on the greybody factor for the obtained dRGT bla...

In this paper, we study the quantum-corrected and generalizedf uncertinty principle (GUP)-corrected thermodynamics of the [Formula: see text]-dimensional charged-rotating Achucarro–Ortiz (AO) black hole. The corrected parameters include temperature, entropy, and heat capacity which help to investigate the instability phases of the Achucarro–Ortiz b...

In the context of the dRGT massive gravity coupled with nonlinear electrodynamics, we present new dRGT black hole solutions. Together with the thermodynamical properties of the solutions, we study the greybody factor of the corresponding black hole solution. To this end, we compute the rigorous bound on the greybody factor for the obtained dRGT bla...

In this work, the Dirac equation is studied in the [Formula: see text] Lifshitz black hole ([Formula: see text]LBH) spacetime. The set of equations representing the Dirac equation in the Newman–Penrose (NP) formalism is decoupled into a radial set and an angular set. The separation constant is obtained with the aid of the spin weighted spheroidal h...

In this work, we consider a class of hyperscaling violating Lifshitz-like black branes with metric scaling components $z=2$ and $\theta=-1$ whose corresponding holographic model can be treated as a non-relativistic fluid exhibiting Lifshitz-type symmetry. Having performed analytical calculations via the Klein-Gordon equation and the linear response...

We study the shadow and energy emission rate of a spherically symmetric noncommutative black hole in Rastall gravity. Depending on the model parameters, the noncommutative black hole can reduce to the Schwarzschild black hole. Since the nonvanishing noncommutative parameter affects the formation of event horizon, the visibility of the resulting sha...

This study investigated quantum tunneling of spin half particles through the event horizon of Rindler modified Schwarzschild black hole (RMSBH) in the presence of quintessence matter. We analyzed the thermodynamics of RMSBH in the Kiselev coordinates. Particularly, exploring RMSBH's entropy and the thermal stability of the RMSBH. We showed that RMS...

In this paper, we use a new asymptotically flat and spherically symmetric solution in the generalized Einstein-Cartan-Kibble-Sciama (ECKS) theory of gravity to study the weak gravitational lensing and its shadow cast. To this end, we first compute the weak deflection angle of generalized ECKS black hole using the Gauss–Bonnet theorem in plasma medi...

We study the quasinormal modes and thermal radiation of massless spin-0 field perturbations in the background of four-dimensional (4D) non-Abelian charged Lifshitz black branes with \(z=2\) hyperscaling violation, which correspond to systems with superconducting fluctuations. After having an analytical solution to the Klein–Gordon equation, we obta...

In this paper, we apply the topological method to the various black holes to derive their Hawking temperature. We show that the this method can easily be employed to compute the Hawking temperature of black holes having spherically symmetric topology. Therefore, we conclude that the topological method provides a consistent formula to achieve the Ha...

We study the timelike geodesics and the greybody radiation of the Schwarzschild black hole surrounded by quintessence field. Quintessence field is one of the highly plausible models for the dark energy. The effective potential along with the structure of the possible orbits for test particles in view of the various values of quintessence parameter...

Charged massless scalar field perturbations are analyzed in the gravitational, electromagnetic, and dilaton fields of linear dilaton black holes. After separating the covariant Klein–Gordon equation (KGE) into radial and angular parts, we show how one obtain the analytical solutions of the radial equation in terms of the confluent Heun functions. T...

In this paper, we examine the Hawking radiation of the Grumiller black hole via the quantum tunneling of fermions. To this end, we consider the Dirac equation in that black hole geometry. It is shown that the surface temperatures of the event horizon in either coordinate systems [singular and non-singular (Painléve–Gullstrand)] correspond to the st...

The effect of Lorentz symmetry breaking (LSB) on the Hawking radiation of Schwarzschild-like black hole found in the bumblebee gravity model (SBHBGM) is studied in the framework of quantum gravity. To this end, we consider Hawking radiation spin-0 (bosons) and spin-1 2 particles (fermions), which go in and out through the event horizon of the SBHBG...

We study the light rays in a static and spherically symmetric gravitational field of null aether theory (NAT). To this end, we employ the Gauss-Bonnet theorem to compute the deflection angle by a NAT black hole in the weak limit approximation. Using the optical metrics of the NAT black hole, we first obtain the Gaussian curvature and then calculate...

We study the light rays in a static and spherically symmetric gravitational field of null aether theory (NAT). To this end, we employ the Gauss-Bonnet theorem to compute the deflection angle by a NAT black hole in the weak limit approximation. Using the optical metrics of the NAT black hole, we first obtain the Gaussian curvature and then calculate...

The deflection angle of Kerr-MOG black holes is studied for different values of the parameter in modified gravity (MOG). To this end, we employ the Gauss-Bonnet theorem, which was first studied by Gibbons and Werner and then extended by Ono, Ishihara and Asada, who use a generalized optical metric where the deflection of light for an observer and s...

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 sepa...