arXiv subjects

Bilel Hamil

Publications and source records attributed to Bilel Hamil.

8 recordsLinked to original sources

arXiv2026

Thermodynamics, Phase Transitions, and Geodesic Structure of F(R)-Phantom Banados-Teitelboim-Zanelli (BTZ) Black Holes

This paper investigates phantom BTZ black holes within the high-curvature gravity theory framework, specifically using a special case of power-Maxwell theory, which functions as a nonlinear electrodynamics source called F(R)-conformally invariant Maxwell gravity. We examine how the phantom or anti-Maxwell field affects the structure of these black holes and how the theory's parameters influence their horizon structure. Additionally, we derive the conserved and thermodynamic potentials associated with these black holes, thereby establishing their conformance to the foundational first law of thermodynamics. Next, the stability characteristics of BTZ black holes endowed with phantom and Maxwell fields are explored under canonical and grand canonical ensemble conditions by inspecting their heat capacity and Gibbs free energy profiles. This assessment reveals how the phantom field and scalar curvature affect these stability regions. We then perform a rigorous analytical verification of the Ehrenfest equations to determine whether the critical behavior of the phantom BTZ black hole corresponds to a second-order phase transition. Our results demonstrate adherence to both Ehrenfest relations, thereby confirming the occurrence of a second-order phase transition within the black hole system concurrent with the critical point. Furthermore, we explore the geodesic structure of the obtained solutions to analyze the motion of massive and massless test particles in the $F(R)$-phantom BTZ spacetime. The analysis demonstrates that stable timelike circular orbits exist only in the phantom regime for negative curvature backgrounds, while the phantom configuration also allows for stable circular photon orbits. These results underscore the significant influence of the phantom field and the F(R) correction on the spacetime geometry and orbital dynamics.

gr-qc↗

arXiv2026

Born-Infeld AdS Black Holes Surrounded by Perfect Fluid Dark Matter

We obtain exact charged AdS black hole solutions in Einstein Lambda gravity including the effects of Born Infeld nonlinear electrodynamics and Perfect Fluid Dark Matter. The influence of the PFDM and BI parameters on the event horizon is analyzed. We compute the conserved and thermodynamic quantities and verify that they satisfy the first law of thermodynamics. Thermal stability is studied in the canonical ensemble using the heat capacity and Helmholtz free energy showing how PFDM and BI parameters affect local and global stability regions. We further investigate the thermodynamics in the extended phase space by treating the cosmological constant as thermodynamic pressure obtaining consistent conserved quantities and confirming the first law. The Ehrenfest equations are analytically verified demonstrating that the critical behavior corresponds to a second order phase transition. Heat engines associated with these black holes are also constructed to examine how PFDM and BI parameters influence their efficiency. Finally we analyze the geodesic structure through timelike and null trajectories using the effective potential determining conditions for stable and unstable circular orbits the innermost stable circular orbit and the photon sphere. PFDM significantly modifies the orbital structure while BI corrections are weaker.

gr-qc↗

arXiv2026

Thermal aspects and particle dynamics of Euler-Heisenberg AdS black hole in 4D Einstein Gauss-Bonnet gravity

We construct charged AdS black hole solutions in four dimensional Einstein Gauss Bonnet gravity coupled to Euler Heisenberg nonlinear electrodynamics and investigate their physical properties. The modified field equations admit black hole solutions whose horizon structure is significantly affected by higher-curvature and nonlinear electromagnetic corrections, allowing for multiple horizons depending on the model parameters. In the extended phase space, where the cosmological constant is interpreted as thermodynamic pressure, we analyze the thermodynamic behavior and show that both the Gauss Bonnet coupling and the Euler Heisenberg parameter induce notable modifications in the equation of state, critical behavior, and thermal stability. Interpreting the black hole mass as enthalpy, we study the Joule-Thomson expansion and determine the inversion temperature and pressure, demonstrating that higher curvature and nonlinear electrodynamic effects substantially influence the cooling and heating regions. Finally, we examine time-like geodesics and show that Gauss Bonnet corrections significantly modify the effective potential, orbital stability, and particle motion in the strong-field regime

gr-qc↗

arXiv2026

Thermodynamic and Dynamical Properties of Phantom Charged Black Holes in 4D Einstein-Gauss-Bonnet Gravity

We present charged black hole solutions of regularized four dimensional Einstein Gauss Bonnet gravity coupled to a phantom electromagnetic field. We investigate the combined effects of higher curvature corrections and phantom charge on the horizon structure, thermodynamics, geodesic motion, and scalar perturbations. The phantom sector exhibits properties that differ qualitatively from those of the ordinary Maxwell case, including the absence of critical thermodynamic behavior and persistent thermal instability. Circular geodesics and accretion efficiency are also significantly modified. Quasinormal modes are computed using the sixth-order WKB approximation and verified through time-domain evolution. The results reveal characteristic signatures of both the Gauss Bonnet coupling and phantom electrodynamics, while confirming linear stability against scalar perturbations.

gr-qc↗

arXiv2025

Uncertainty Relation for Pseudo-Hermitian Quantum Systems

This study investigates pseudo-Hermitian quantum mechanics, where the Hamiltonian satisfies a modified Hermiticity condition. We extend the uncertainty relation for such systems, demonstrating its equivalence to the standard Hermitian case within a pseudo-Hermitian inner product. Analytical solutions to the time-dependent Schr\"odinger equation with a linearly evolving potential are derived. Furthermore, we show that the uncertainty relation for position and momentum remains real and greater than 1/2, highlighting the significance of non-Hermitian systems in quantum mechanics.

quant-ph↗

arXiv2024

Schwarzschild black hole surrounded by a cloud of strings in the background of perfect fluid dark matter

This manuscript investigates a Schwarzschild black hole surrounded by perfect fluid dark matter embedded in a cloud of strings. The effects of its surroundings on thermodynamics, timelike and null geodesics, shadows, and quasinormal modes are analyzed. It is demonstrated that changes in spacetime, induced by the surrounding environment, significantly influence the stability, thermal phases, energy dynamics, particle trajectories, and observable features of the black hole's shadow, as well as the oscillation frequency and decay rate.

gr-qc↗

arXiv2022

Higher order GUP black hole based on COW experiment and Einstein-Bohr's photon box

In this work we have explored the effects of higher order generalized uncertainty principle (GUP), inspired from the quantum gravity COW experiment and the Einstein-Bohr's photon box thought experiment, on the properties of a black hole. Two different GUP models, namely, GUP to all orders in the Planck length model, and GUP with minimal length uncertainty and maximal momentum model are considered for our study. For each model, we have investigated the modified de Broglie formula, modification in gravitational phase shift, Einstein-Bohr's photon box, and the modified Hawking temperature and the tidal force of the GUP modified black hole.

gr-qc↗

arXiv2021

Black hole thermodynamics in the presence of a maximal length and minimum measurable in momentum

In this work, incorporating the effect of the minimum measurable in momentum and maximal length, we studied thermodynamics property of Schwarzschild black hole and the Unruh effect. {\color{red} According to this scenario, we see that the black hole temperature cannot be smaller than a certain minimum value of $ T_{\min} $. Moreover, we find that black hole mass cannot be larger than a maximum mass value of $M_{\max }$. Considering these findings first we compute the corrected Hawking temperature versus the mass and examine its characteristic behavior. Then, we derive the black hole's entropy and heat capacity. We find that the black hole is stable when $\frac{M_{\max }}{\sqrt{3}}<M<M_{\max }$. Finally, we examined the modified Unruh effect. We find that the modified Unruh temperature explicitly depends on $\alpha$.

gr-qc↗