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Muhammad Yasir

Publications and source records attributed to Muhammad Yasir.

8 recordsLinked to original sources

R\'enyi Entropy and the Topological Features of Charged AdS Black Hole

This study applies Duan's topological current $\phi$-mapping theory to investigate a newly proposed charged modified AdS black hole using the R\'enyi entropy formalism, examining its thermodynamic properties across the canonical, mixed, and grand canonical ensembles.} Electric and magnetic charges are fixed in the canonical ensemble, whereas the mixed ensemble incorporates electric and magnetic potentials. The grand canonical ensemble, meanwhile, ensures consistency by employing these potentials exclusively. Initially, we compute topological charges by identifying critical points in each ensemble. In both the canonical and mixed ensembles, we identify a conventional critical point with a topological charge of $-1$. We then model the black hole's domain in the AdS regime as a topological defect in thermodynamic space and analyze its local and global topology by calculating the winding numbers at these defect locations. {Interestingly, the canonical and mixed ensembles exhibit identical black hole topologies, each possessing a total topological charge of $1$ within the framework of the R\'enyi entropy.} Finally, we characterize the canonical, mixed, and grand canonical ensembles based on the presence of generation/annihilation points: the canonical ensemble has one such point, the mixed ensemble has a negative one, and the grand canonical ensemble has none.

physics.gen-ph

Harmonic oscillation and orbital morphology for spinning charged quantum corrected black hole

This study investigates the dynamical behavior of particle's test around a spinning charged Einstein-Maxwell-dilaton (EMd) quantum corrected black hole (QCBH) by examining the effects of spinning parameter $a$, quantum correction parameter $b$, and charge parameter $Q$. Using EMd spacetime geometry, we analyze the effective potential and effective force to determine the stability and structure of the circular orbits in a strong gravitational field. Furthermore, we calculate the oscillation frequencies radial $(\Omega_r)$, vertical $(\Omega_\theta)$, and angular $(\Omega_\phi)$, as well as the corresponding Periapsis and Lense-Thirring precession frequencies. The spin parameter primarily determines the spinning properties of spacetime, while the quantum correction and charge particle introduce additional biases to Kerr-Newman geometry, particularly near the event horizon. These corrections alter the position and stability of the circular orbits, and the spectrum effectively associates with particle's motion. The results provide a comprehensive description of the orbital dynamics of spinning EMd QCBH through future high-precision astrophysical observations.

gr-qc

Differential topology and micro-structure of black hole in Einstein-Euler-Heisenberg spacetimes with exponential entropy

Exact black holes in the Einstein Euler-Heisenberg theory are explored with an exponential entropy framework by using the topological current $\Psi$-mapping theory. The topology classes are investigated through the canonical, mixed, and grand canonical ensembles. In particular, the magnetic charge is fixed for the canonical ensemble, whereas the magnetic potential is included for the mixed ensemble and the grand canonical ensemble with maintaining its consistency through the magnetic potential. The topological charges are analyzed for each ensemble through critical points. As a result, it is found that the canonical, mixed, and grand canonical ensembles lead to either $1$, $-1$, or no generation/annihilation points. Moreover, it is shown how temperature and heat capacity depend on the horizon radius in order to verify the stability of a black hole. Furthermore, the behavior of the thermodynamic curvatures of a black hole is investigated through the geometric methods.

gr-qc

Thermal analysis of black hole in de Rham--Gabadadze--Tolley massive gravity in Barrow entropy framework

This study examines a recently hypothesized black hole solution in de Rham--Gabadadze--Tolley massive gravity. Firstly, we consider the negative cosmological constant as a thermodynamic pressure. We extract the thermodynamical properties such as Hawking temperature, heat capacity and Gibbs free energy using the Barrow entropy. We also obtain a new pressure associated to the perfect fluid dark matter and discuss the first-order van der Waals-like phase transition. This black hole's stability is investigated through specific heat and Gibbs free energy. Also, we analyze the thermodynamic curvatures behavior of black hole through geometry methods (Weinhold, Ruppeiner, Hendi-Panahiyah-Eslam-Momennia (HPEM), and geometrothermodynamics (GTD)).

gr-qc

Joule-Thomson expansion and tidal force effects of AdS black holes surrounded by Chaplygin dark fluid

This study examines a recently hypothesized black hole. We study the Joule-Thomson coefficient, the inversion temperature and also the isenthalpic curves in the $T_i -P_i$ plane. A comparison is made between the Van der Waals fluid and the black hole to study their similarities and differences. The Joule-Thomson coefficient, the inversion curves and the isenthalpic curves are discussed inAdS black holes surrounded by Chaplygin dark fluid. In $T -P$ plane, the inversion temperature curves and isenthalpic curves are obtained with different parameters. Next, we explore the radial timelike geodesics that leads us to explore the tidal force effects for a radially in-falling particle in such black hole spacetime. We also numerically solve the geodesic deviation equation for two nearby radial geodesics for a freely falling particle. Our analysis shows that contrary to the Schwarzschild spacetime, the tidal forces don't become zero at spatial infinity due to the lack of asymptotic flatness because of the presence of a non-zero cosmological constant. The geodesic separation profile shows an oscillating trend and depends on the dynamic spacetime parameters $q, B$ and $\Lambda$.

gr-qc

Testing new massive conformal gravity with the light deflection by black hole

We study the weak gravitational lensing effect of Non-Bocharova-Bronnikov-Melnikov-Bekenstein (BBMB) black hole in new massive conformal gravity. We analyze the deflection angle of light caused by new massive conformal gravity by using the gauss-bonnet theorem. As a consequence, we obtain the gaussian optical curvature and calculate the deflection angle of the new massive conformal gravity for spherically balanced spacetime with the gauss-bonnet theorem. The resultant deflection angle of light in the weak field limits showing that the bending of light is a global and topological phenomenon. Furthermore, we identify the deflection angle of light in the framework of the plasma medium, we also demonstrate the effect of a plasma medium on the deflection of light by non BBMB. In addition, the behavior of the deflection angle by new massive conformal gravity is explicitly shown in the influence of plasma medium and for the non plasma medium.

gr-qc

Thermal analysis and Joule-Thomson expansion of black hole exhibiting metric-affine gravity

This study examines a recently hypothesized black hole, which is a perfect solution of metric-affine gravity with a positive cosmological constant, and its thermodynamic features as well as the Joule-Thomson expansion. We develop some thermodynamical quantities, such as volume, Gibbs free energy, and heat capacity, using the entropy and Hawking temperature. We also examine the first law of thermodynamics and thermal fluctuations, which might eliminate certain black hole instabilities. In this regard, a phase transition from unstable to stable is conceivable when the first law order corrections are present. Besides that, we study the efficiency of this system as a heat engine and the effect of metric-affine gravity for physical parameters $q_e$, $q_m$, $\kappa_{\mathrm{s}}$, $\kappa_{\mathrm{d}}$ and $\kappa_{\mathrm{sh}}$. Further, we study the Joule-Thomson coefficient, and the inversion temperature and also observed the isenthalpic curves in the $T_i -P_i$ plane. In metric-affine gravity, a comparison is made between the Van der Waals fluid and the black hole to study their similarities and differences.

gr-qc

Barriers for Social Inclusion in Online Software Engineering Communities -- A Study of Offensive Language Use in Gitter Projects

Social inclusion is a fundamental feature of thriving societies. This paper first investigates barriers for social inclusion in online Software Engineering (SE) communities, by identifying a set of 11 attributes and organising them as a taxonomy. Second, by applying the taxonomy and analysing language used in the comments posted by members in 189 Gitter projects (with > 3 million comments), it presents the evidence for the social exclusion problem. It employs a keyword-based search approach for this purpose. Third, it presents a framework for improving social inclusion in SE communities.

cs.SE