arXiv subjects

Abdelmalek Bouzenada

Publications and source records attributed to Abdelmalek Bouzenada.

At least 37 records · Page 2Linked to original sources

arXiv2025

Quantum-Corrected Deformation of RN-AdS Black Holes with a Cloud of Strings Immersed in Quintessential-like Fluid

Inspired by Loop Quantum Gravity (LQG), we investigate the Reissner-Nordström (RN) black hole (BH) solution coupled with a cloud of strings in an anti-de Sitter (AdS) background, surrounded by a quintessence-like fluid. We begin by analyzing the optical properties of the BH through null geodesic motion, deriving an effective potential that governs photon dynamics. This effective potential is central to understanding key phenomena such as photon trajectories, circular null orbits, photon sphere, and the resulting BH shadow. Subsequently, we study the dynamics of neutral test particles by deriving effective potential that describes their motion. Using the potential, we compute the specific energy and specific angular momentum of neutral particles in circular orbits around the BH and analyze the outcomes. We also investigate the innermost stable circular orbits (ISCO) and demonstrate how various geometrical and physical properties influence the radius of ISCO. Furthermore, we explore the thermodynamic properties of the BH solution by deriving key quantities such as the Hawking temperature, entropy, Gibbs free energy, internal energy, and specific heat capacity. Throughout the study, we demonstrate that the geodesic structure, scalar field behavior, and thermodynamic properties are significantly influenced by parameters such as the string cloud, quantum correction, electric charge, the surrounding quintessence-like fluid, and the AdS curvature radius.

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arXiv2025

Schwarzschild-AdS Black Holes with Cloud of Strings and Quintessence: Geodesics, Thermodynamic Topology, and Quasinormal Modes

In this study, we explore a Schwarzschild-anti de-Sitter black hole (BH) coupled with a cloud of strings (CoS) possessing both electric- and magnetic-like components of the string bivector, embedded in a Kiselev-type quintessence fluid (QF). We analyze the dynamics of photons and test particles, focusing on trajectories, photon spheres, BH shadows, and innermost stable circular orbits (ISCO), highlighting how CoS and QF parameters affect these features. We then examine the thermodynamic topology of the system by analyzing vector field zeros, showing that varying CoS leads to distinct topological configurations with total charges of either $0$ or $+1$, corresponding to known classes like RN and AdS-RN. Additionally, we study scalar field dynamics via the massless Klein-Gordon equation, reformulated into a Schr$\ddot{o}$dinger-like form to derive the effective potential. We compute the quasinormal modes (QNMs) of scalar perturbations, showing how CoS and QF influence oscillation frequencies and damping rates, with implications for gravitational confinement and thermalization in the AdS/CFT context.

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arXiv2025

Noncommutative Geometry Inspired AdS Black Hole with a Cloud of Strings Surrounded by Quintessence-like fluid

We investigate the geometric and physical properties of an anti-de Sitter (AdS) black hole space-time coupled by a cloud of strings and surrounded by a quintessence-like fluid, all within the framework of non-commutative (NC) geometry. From the perspective of geometrical optics, we analyze the behavior of null geodesics, focusing on key optical features such as the effective potential, the structure and radius of the photon sphere, light deflection angles, photon trajectories, and the resulting black hole (BH) shadow. Our findings show that the combined effects of the string cloud and quintessence-like fluid significantly modify photon dynamics and optical observables, leading to notable deviations from standard BH scenarios in NC geometry background. We also examine time-like geodesics, with particular emphasis on the innermost stable circular orbits (ISCOs). The results demonstrate that the presence of geometric matter components alters the ISCO radius compared to conventional solutions. In addition, we explore the thermodynamic behavior of the BH, deriving expressions for the Hawking temperature, entropy, Gibbs free energy, and specific heat capacity. The influence of the string cloud and quintessence-like fluid introduces substantial modifications to the thermodynamic profile, including shifts in phase transition points and changes to stability conditions under NC geometric effects. Furthermore, we study the dynamics of massless scalar field perturbations in this modified background by formulating the Klein-Gordon equation and reducing it to a Schrödinger-like form via separation of variables. The resulting effective potential is analyzed in detail, highlighting the significant role of both the string cloud and the quintessence-like fluid in shaping the perturbative landscape within the NC geometry setting.

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arXiv2025

Thermal Behavior of Generalized Black-Bounce Black Hole Model

In this work, we tested the thermal behavior of a class of regular black hole solutions defined as generalized black-bounce spacetimes. We introduce several novel configurations governed by different mass functions and geometric deformations, illustrated by parameters controlling regularity and horizon structure. Using the Hamilton Jacobi tunneling method, we compute the Hawking temperature associated with each model and analyze its dependence on the underlying parameters. We find that all proposed geometries are free of curvature singularities and exhibit positive, well defined quasi-local masses in the Hernandez Misner Sharp formalism. Also, we demonstrate that these models may possess multiple horizons, including extremal and asymmetric cases, while typically violating classical energy conditions in the vicinity of the bounce. Our results show and illustrate the structure and thermodynamic stability of these regular solutions.

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arXiv2025

Thermodynamics of BTZ-type charged black holes in Bopp Podolsky electrodynamics

We tested the thermodynamic properties of charged BTZ-type black holes (BHs) in the framework of Bopp Podolsky electrodynamics, a higher derivative extension of Maxwells theory that preserves gauge invariance while introducing a massive photon mode. Using a perturbative approach, we derive first and second order corrections to the metric and electric field, revealing how the Bopp Podolsky parameter b modifies the geometry and horizon structure. Unlike in four dimensional illustrations, where such corrections can lead to wormhole solutions, the (2+1)dimensional case retains a black hole interpretation, albeit with curvature dependent deformations that vanish asymptotically. We compute the Hawking temperature via the Hamilton Jacobi tunneling method, demonstrating its dependence on both the cosmological constant and the Bopp Podolsky coupling. Our results indicate that while energy conditions are marginally violated for certain parameter regimes, the BHs thermodynamic behavior remains well-defined, with temperature corrections emerging from the interplay between higher derivative electrodynamics and the lower dimensional gravitational background.

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arXiv2025

Geodesics, Scalar Fields, and GUP-Corrected Thermodynamics of Charged BTZ-like Black Holes in Bopp-Podolsky Electrodynamics

In Ref. [1], the spacetime geometry generated by compact objects in $(2+1)$-dimensional Bopp-Podolsky electrodynamics is derived. Using a perturbative approach, the authors derived a charged BTZ-like black hole solution and computed corrections up to second order in a perturbative expansion valid far from the horizon. In this work, we investigate the same circularly symmetric three-dimensional charged BH solution pierced by disclinations. We begin by analyzing the motion of photons within this spacetime, focusing on how the geometric parameters influence the effective potential governing null geodesic motion. The corresponding equations of motion are derived, and the resulting orbital dynamics are explored through graphical methods to show the influence of key parameters including the BH mass $M$, electric charge $Q$, cosmological constant $Λ$, and BP coupling parameter $b^2$. Extending our analysis to wave dynamics, we examine the propagation of massless scalar fields in the BH solution by solving the Klein-Gordon equation. Through suitable coordinate transformations, we derive a Schrödinger-like equation with an effective potential that encodes the influence of the topological defect and electromagnetic corrections. Additionally, we investigate quantum gravitational effects by applying the Generalized Uncertainty Principle (GUP) to derive a GUP-corrected Hawking temperature, revealing systematic suppression of thermal radiation that could lead to stable BH remnants. Finally, we compute Keplerian frequencies for circular orbits, demonstrating how the interplay between charge, nonlinear electrodynamics, and disclination parameters creates distinctive observational signatures that could potentially test modified gravity theories in strong-field regimes.

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arXiv2025

Rainbow gravity effects on quantum dynamics of scalar and oscillator fields in a topological defect cosmological space-time

In this paper, we investigate the quantum dynamics of scalar and oscillator fields in a topological defect space-time background under the influence of rainbow gravity's. The rainbow gravity's are introduced into the considered cosmological space-time geometry by replacing the temporal part $dt \to \frac{dt}{\mathcal{F}(χ)}$ and the spatial part $dx^i \to \frac{dx^i}{\mathcal{H} (χ)}$, where $\mathcal{F}, \mathcal{H}$ are the rainbow functions and $χ=E/E_p$. We derived the radial equation of the Klein-Gordon equation and its oscillator equation under rainbow gravity's in topological space-time. To obtain eigenvalue of the quantum systems under investigations, we set the rainbow functions $\mathcal{F}(χ)=1$ and $\mathcal{H}(χ)=\sqrt{1-β\,χ^p}$, where $p=1,2$. We solve the radial equations through special functions using these rainbow functions and analyze the results. In fact, it is shown that the presence of cosmological constant, the topological defect parameter $α$, and the rainbow parameter $β$ modified the energy spectrum of scalar and oscillator fields in comparison to the results obtained in flat space.

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arXiv2025

Cylindrical black hole solutions in $f(\mathcal{R})$ and $f(\mathcal{R},\mathcal{A},A^{μν}A_{μν})$ modified gravity

We explore a cylindrical black hole (BH) space-time introduced by Lemos, in the context of modified gravity theories. Specifically, we focus on $f(\mathcal{R})$-gravity framework, where we choose two form functions, $f(\mathcal{R})=(\mathcal{R}+α_1\,\mathcal{R}^2+α_2\,\mathcal{R}^3+α_3\,\mathcal{R}^4+α_4\,\mathcal{R}^5)$ and $f(\mathcal{R})=\mathcal{R}+α_k\,\mathcal{R}^{k+1},\quad (k=1,2,...n)$. We solve the modified field equations incorporating zero energy-momentum tensor, $\mathcal{T}^{μν}=0$ and obtain the result. Moreover, we study another well-known modified gravity theory called Ricci-Inverse ($\mathcal{RI}$) gravity and investigate this Lemos black hole (LBH) space-time. To achieve this, we consider different classes of models defined as follows: (i) Class-\textbf{I} model: $f(\mathcal{R}, \mathcal{A})=(\mathcal{R}+β\,\mathcal{A})$, (ii) Class-\textbf{II} model: $f(\mathcal{R}, A^{μν}\,A_{μν})=(\mathcal{R}+γ\,A^{μν}\,A_{μν})$, and (iii) Class-\textbf{III} model: $f(\mathcal{R}, \mathcal{A}, A^{μν}\,A_{μν})=(\mathcal{R}+α_1\,\mathcal{R}^2+α_2\,\mathcal{R}^3+β_1\,\mathcal{A}+β_2\,\mathcal{A}^2+γ\,A^{μν}\,A_{μν})$, where $\mathcal{A}=g_{μν}\,A^{μν}$ is the anti-curvature scalar, $A^{μν}$ is the anti-curvature tensor, the reciprocal of the Ricci tensor $R_{μν}$. We solve the modified field equations under the same aforementioned scenario of energy-momentum tensor, and obtain the result. Subsequently, we study the geodesic motions of test particles around this LBH within the Ricci-Inverse and $f(\mathcal{R})$-gravity theories and analyze the outcomes. We demonstrate that different coupling constants chosen in these modified gravity theories influences the usual cosmological constant $Λ$, and thus, shifted the result in comparison to the general relativity case.

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arXiv2025

Fermionic fields in a four-dimensional Bonnor-Melvin-Lambda space-time

In this paper, we investigate how the gravitational field generated by a four-dimensional electrovacuum cosmological space-time influences the dynamics of fermionic fields governed by the Dirac equation, while also considering the effects of topology. We derive the radial wave equation corresponding to the relativistic Dirac equation and subsequently obtain analytical solutions for the energy levels and wave functions of the fermionic field within our chosen framework. Our analysis reveals that various parameters, including geometric topology, the cosmological constant, and quantum numbers, play significant roles in determining the eigenvalue solution of the quantum particles. Specifically, we demonstrate that the presence of the topological parameter disrupts the degeneracy of the energy spectrum.

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arXiv2024

Scalar, Vector Perturbations and Effective Hawking Radiation of Cylindrical Black Holes in $f(\mathcal{R})$ and Ricci-Inverse Gravity

This paper investigates scalar perturbations and quasinormal modes (QNMs) associated with cylindrical black holes constructed within the frameworks of $f(\mathcal{R})$-gravity and Ricci-Inverse ($\mathcal{RI}$) gravity. Moreover, we study the modified Hawking radiation in these black hole solutions and analyze the effects of coupling constants. These modified theories, which extend general relativity by introducing higher-order curvature corrections and additional geometric terms, provide a rich platform for exploring deviations from standard gravitational physics. The study begins by revisiting the cylindrical black holes in these modified gravity theories, where the effective cosmological constants respectively, are represented by $Λ_m^{f(\mathcal{R})}$ and $Λ_m^{\mathcal{RI}}$ related to the coupling constants unique to each framework. Afterwards, the QNMs, intrinsic damped oscillations of the black hole space-time, are analyzed to probe the stability of the system, with the effective potential $V$ revealing the impact of the modified gravity parameters. Additionally, the thermodynamic properties of the black holes are examined through the lens of the Generalized Uncertainty Principle (GUP), which introduces quantum corrections to Hawking radiation. The GUP-modified Hawking temperature and entropy are derived, demonstrating significant deviations from classical results and highlighting the quantum gravitational effects in these modified frameworks. By linking QNMs, thermodynamics, and quantum corrections, this work not only deepens the understanding of modified gravity theories but also offers potential observational pathways to test their validity.

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arXiv2024

Stationary BTZ space-time in Ricci-Inverse and $f(\mathcal{R})$ gravity theories

In this paper, we explore a stationary BTZ space-time within the framework of modified gravity theory, specifically focusing on Ricci-inverse gravity. It is important to clarify that ``Ricci-inverse" refers to the inverse of the Ricci tensor, not the Ricci scalar. We consider a general class of this gravity theory, where the function $f$ is defined by $f(\mathcal{R}, \mathcal{A}, A^{μν}\,A_{μν})$, with $\mathcal{R}$ and $\mathcal{A}$ representing the Ricci and anti-curvature scalars, respectively and $A^{μν}$ is the anti-curvature tensor. We demonstrate that stationary BTZ space-time is a valid solution in this gravity theory, wherein the cosmological constant undergoes modifications due to the coupling constants. Moreover, we study another modified gravity theory known as $f(\mathcal{R})$-gravity and analyze the stationary BTZ space-time. Subsequently, we fully integrate the geodesic equations for BTZ space-time constructed within the Ricci-Inverse gravity, expressing the solutions in terms of elementary functions and compared with the GR result. We classify different types of geodesics, including null and time-like geodesics, under three conditions: (i) nonzero mass and angular momentum, $M \neq 0, J\neq 0$, (ii) massless BTZ space-time, $M=0$ and $J=0$, and (iii) $M=-1, J=0$, that is $AdS_3$-type, and analyze the results in modified gravity theories and compare with the general relativity case.

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arXiv2024

Effects of gravity rainbow on scalar bosonic and oscillator fields in Bonnor-Melvin space-time with a cosmological constant

In this paper, we explore the relativistic quantum motion of spin-zero scalar charge-free particles influenced by rainbow gravity's (RG's) in Bonnor-Melvin magnetic space-time, a four-dimensional solution featuring a positive cosmological constant. We solve the Klein-Gordon equation in this scenario by using two sets of rainbow function: (i) $f(χ)=\frac{1}{(1-β\,χ)}$,\,\, $h(χ)=1$ and (ii) $f(χ)=\frac{1}{(1-β\,χ)}=h(χ)$, where $0 < χ\left(=\frac{|E|}{E_p}\right) \leq 1$ with $E_p$ being the Planck's energy, $E$ is the particle's energy, and $β$ is the rainbow parameter. Furthermore, we study the relativistic quantum oscillator through the Klein-Gordon oscillator equation in the same Bonnor-Melvin magnetic space-time under RG effects. Employing the first pair of rainbow function, we obtain an approximate eigenvalue solution of the quantum oscillator fields. Notably, we demonstrate that the relativistic energy profile of scalar and oscillator particles are influenced by the topology of the geometry and the cosmological constant which is related with the magnetic field strength lies along the symmetry axis. Additionally, we see the impact of rainbow parameter on these approximate relativistic energy profiles in both quantum systems.

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arXiv2024

Harmonic oscillator system in topologically charged Eddington-inspired Born-Infeld gravity space-time and Wu-Yang magnetic monopole

We investigate the quantum dynamics of a harmonic oscillator (HO) system within the framework of topologically charged Eddington-inspired Born-Infeld (EiBI) gravity space-time. Additionally, we incorporate the Wu-Yang magnetic monopole (WYMM) into the quantum system and analyze the influences of modified gravity, the topological charge, and WYMM on this HO quantum mechanical system. Using analytical methods, we derive the energy eigenvalues and the corresponding eigenfunctions of the HO. Moreover, we consider a scenario where the EiBI-gravity parameter is absent and introduce an inverse square potential, including the WYMM, into the HO system. Our findings show significant deviations in the behavior of the HO system compared to the traditional quantum mechanical HO model, including alterations in the bound-state spectra and eigenfunctions. These results provide valuable insights into the interplay between quantum mechanical problems and alternative gravitational theories.

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arXiv2024

PDM relativistic quantum oscillator in Einstein-Maxwell-Lambda space-time

In this analysis, we study the dynamics of quantum oscillator fields within the context of a position-dependent mass (PDM) system situated in an Einstein-Maxwell space-time, incorporating a non-zero cosmological constant. The magnetic field is aligned along the symmetry axis direction. To analyze PDM quantum oscillator fields, we introduce a modification to the Klein-Gordon equation by substituting the four-momentum vector $p_μ \to \Big(p_μ+i\,η\,X_μ+i\,\mathcal{F}_μ\Big)$ into the Klein-Gordon equation, where the four-vector is defibed by $X_μ=(0, r, 0, 0)$, $\mathcal{F}_μ=(0, \mathcal{F}_r, 0, 0)$ with $\mathcal{F}_r=\frac{f'(r)}{4\,f(r)}$, and $η$ is the mass oscillator frequency. The radial wave equation for the relativistic modified Klein-Gordon equation is derived and subsequently solved for two distinct cases: (i) $f(r)=e^{\frac{1}{2}\,α\,r^2}$, and (ii) $f(r)=r^β$, where $α\geq 0, β\geq 0$. The resultant energy levels and wave functions for quantum oscillator fields are demonstrated to be influenced by both the cosmological constant and the geometrical topology parameter which breaks the degeneracy of the energy spectrum. Furthermore, we observed noteworthy modifications in the energy levels and wave functions when compared to the results derived in the flat space background.

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arXiv2024

Scalar fields in Bonnor-Melvin Universe with potential: A study of dynamics of spin-0 particles-antiparticles

This research focus on the investigation of relativistic quantum dynamics of spin0 scalar particles/fields through the utilization of the Klein-Gordon (KG) equation within the framework of an electrovacuum space-time in the presence of an external scalar potential. Specifically, we focus on a cylindrical symmetric Bonnor-Melvin magnetic universe with a cosmological constant, where the magnetic field aligns along the symmetry axis direction. We derive the radial wave equation of the KG-equation by considering a Cornell-type scalar potential in the background of magnetic universe and successfully obtain an analytical eigenvalue solution for spin-0 quantum system. Notably, our findings reveal that both the energy spectrum and the corresponding radial wave function are significantly influenced by the presence of the cosmological constant, the topology parameter of the space-time geometry, which induces a deficit in the angular coordinates, and the potential parameters.

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arXiv2024

Dynamics of Spin-0 (Particles-Antiparticles) in Bonnor-Melvin Cosmological Space-Time Using the Generalized Feshbach-Villars Transformation

In this paper, we employ the Generalized Feshbach-Villars transformation (GFVT) to investigate the relativistic quantum dynamics of spin-0 scalar particles within the backdrop of a magnetic universe characterized by the Bonnor-Melvin cosmological space-time, which exhibits a geometrical topology resulting in an angular deficit. We derive the radial equation of the Klein-Gordon equation using this FV representation and obtain analytical solutions utilizing special functions. Our analysis demonstrates that various parameters associated with the space-time geometry exert significant influence on the eigenvalue solutions within this novel representation. This research sheds light on the intricate dynamics of particles within the theoretical framework of quantum field theory in curved space-time.

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arXiv2024

Quantum dynamics of spin-0 particles in a cosmological space-time

In this paper, our focus is on investigating the impact of cosmological constant on relativistic quantum systems comprising spin-0 scalar particles. Our analysis centers around the Klein-Gordon equation, and we obtain both approximate and exact analytical solutions for spin-0 particles of the quantum system. Afterwards, we explore quantum oscillator fields by considering the Klein-Gordon oscillator within the same space-time characterized by a cosmological constant. We obtain an approximate expression for the energy eigenvalue of the oscillator fields. In fact, the energy spectrum in both scenarios are examined and show the influences of the cosmological constant and geometry's topology. Our investigation is situated within the context of a magnetic universe-a four-dimensional cosmological space-time recognized as the Bonnor-Melvin universe

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arXiv2024

Study of scalar particles through the Klein-Gordon equation under rainbow gravity effects in Bonnor-Melvin-Lambda space-time

In our investigation, we explore the quantum dynamics of charge-free scalar particles through the Klein-Gordon equation within the framework of rainbow gravity's, considering the Bonnor-Melvin-Lambda (BML) space-time background. The BML solution is characterized by the magnetic field strength along the axis of symmetry direction which is related with the cosmological constant $Λ$ and the topological parameter $α$ of the geometry. The behavior of charge-free scalar particles described by the Klein-Gordon equation is investigated, utilizing two sets of rainbow functions: (i) $f(χ)=\frac{(e^{β\,χ}-1)}{β\,χ}$,\, $h(χ)=1$ and (ii) $f(χ)=1$,\, $h(χ)=1+\frac{β\,χ}{2}$. Here $0 < \Big(χ=\frac{|E|}{E_p}\Big) \leq 1$ with $E$ represents the particle's energy, $E_p$ is the Planck's energy, and $β$ is the rainbow parameter. We obtain the approximate analytical solutions for the scalar particles and conduct a thorough analysis of the obtained results. Afterwards, we study the quantum dynamics of quantum oscillator fields within this BML space-time, employing the Klein-Gordon oscillator. Here also, we choose the same sets of rainbow functions and obtained approximate eigenvalue solution for the oscillator fields. Notably, we demonstrate that the relativistic approximate energy profiles of charge-free scalar particles and oscillator fields get influenced by the topology of the geometry and the cosmological constant. Furthermore, we show that the energy profiles of scalar particles get modifications by the rainbow parameter and the quantum oscillator fields by both the rainbow parameter and the frequency of oscillation

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