299 citations · 2.2k across the 79 of their papers we have counts for
82 papers
Acceleration radiation, quasinormal modes and quasi-bound states in generic rotating regular black holes
Uktamjon Uktamov, Ali Övgün, Reggie C. Pantig +1
We study horizon-brightened acceleration radiation for a neutral scalar field in separable Kerr-like rotating metrics with nonlinear-electrodynamic mass profiles. The principal bra…
Four-derivative corrections to the neutral-scalar Christodoulou threshold in charged de Sitter black holes
Reggie C. Pantig
We study leading parity-even four-derivative corrections to the linear Christodoulou regularity criterion for a neutral, massless, minimally coupled spectator scalar in four-dimens…
Maxwell-Jttner averaged nonaffine theory of relativistic shear viscosity
Reggie C. Pantig, Ali Övgün
We formulate a Maxwell-Jüttner averaged extension of relativistic nonaffine shear-viscosity theory for a classical gas of massive particles. The starting point is the relativistic…
Redshift Spectroscopy as a Probe of Regular Black Holes, Black Bounces, and Scalar-Hair Compact Objects
Ali Övgün, Reggie C. Pantig, Joel Saavedra
Motivated by [Phys. Rev. D. 107, 064019 (2023)], we develop a unified and model-independent framework for the spectroscopy of photon frequency shifts in generic static, spherically…
Fixed ADM reconstruction of extended uncertainty principle black holes
Nikko John Leo S. Lobos, Ali Övgün, Reggie C. Pantig
We study a phenomenological fixed-ADM prescription for an extended-uncertainty-principle (EUP) correction to the Schwarzschild exterior. Rather than treat mass constancy as a conse…
Josephson interferometry in an Oppenheimer--Snyder-like scale-dependent black-hole spacetime
Ali Ovgun, Reggie C. Pantig, G. Lambiase
We develop a covariant framework for Josephson transport, superconducting interference, and shunt noise in the scale-dependent exterior generated by an Oppenheimer--Snyder-like col…
Curvature-driven spin transport in rank-two string-Carroll hydrodynamics
Nikko John Leo Lobos, Reggie Pantig
We derive the rank-two string-Carroll limit of the canonical stress--spin Ward system for probe matter on a fixed torsion-free background. Beyond rank-one Carroll spin hydrodynamic…
Optical-area minimum method for static spherical black hole shadows
Vitalii Vertogradov, Nikko John Leo S. Lobos, Ali Ovgun +1
We formulate a global optical-area method for shadows of static, spherically symmetric black holes. For the metric \(ds^{2}=-A(r)dt^{2}+B(r)dr^{2}+C(r)dΩ^{2}\), spherical sections…
Chromatic Weak Lensing by Charged Black Holes with Two Lorentz-Violating Kalb-Ramond Couplings
Ali Övgün, Reggie C. Pantig, Grigoris Panotopoulos
We study weak gravitational lensing and steady spherical test--fluid accretion by a static charged black hole in a Lorentz--violating Kalb--Ramond background with two nonminimal cu…
Two-scale magnetically charged regular black holes from nonlinear electrodynamics and a T-duality-inspired zero-point length
Ali Ovgun, Reggie C. Pantig, Joel Saavedra
We construct a two-scale, static, spherically symmetric regular black hole in Einstein gravity sourced by magnetic nonlinear electrodynamics (NED). The zero-point length reg…
Phase-plane formulation of weak gravitational deflection in static spherical spacetimes
Reggie C. Pantig, Ali Övgün
This paper develops a phase-plane formulation of gravitational light deflection by static and spherically symmetric black holes, with Schwarzschild spacetime as the principal case.…
Density-preserving core-Einasto black holes with Event Horizon Telescope bounds
Ali Övgün, Reggie C. Pantig
A Newtonian halo density does not uniquely determine a relativistic spacetime, and the resulting completion ambiguity can dominate predicted horizon-scale signals. We make this dep…
An obstruction and residual-completion theory for Newman--Janis deformations
Reggie C. Pantig, Ali Övgün
We formulate an obstruction and residual-completion theory for Newman-Janis-type deformations of black hole seeds, where Newman-Janis-type includes both the original complex-coordi…
Spinning particle dynamics, epicyclic frequencies, and transient QPO signatures in Schwarzschild spacetime
Uktamjon Uktamov, Ali Övgün, Reggie C. Pantig +1
We study the motion of spinning test particles in Schwarzschild spacetime within the Mathisson--Papapetrou--Dixon pole--dipole approximation, imposing the Tulczyjew--Dixon spin sup…
Near extremal RN-AdS control of holographic Josephson transport
Ali Övgün, Reggie C. Pantig
We formulate a holographic weak-link construction in which Josephson transport is controlled by the charge sector of a Reissner--Nordstrom-AdS black brane. The model is an Einstein…
Noether charges and the first law of thermodynamics for multifractional Schwarzschild black hole in the q-derivative theory
Reggie C. Pantig
In this paper, we investigate black-hole thermodynamics in the multi-fractional theory with -derivatives, focusing on static, spherically symmetric vacuum solutions in the spher…
Reference-renormalized curvature-primitive Gauss-Bonnet formalism for finite-distance weak gravitational lensing in static spherical spacetimes
Reggie C. Pantig, Ali Övgün
We develop a reference-renormalized (photon-sphere-free) normalization scheme for Gauss-Bonnet gravitational lensing at finite distance in static, spherically symmetric spacetimes.…
Breaking Parameter Degeneracies in a Magnetically Charged Black Hole Embedded in a Hernquist Dark-Matter Halo: A Multi-Observable Analysis
Ali Ovgun, Reggie C. Pantig, Joel Saavedra
We study the degeneracy of intrinsic and environmental parameters for BH observables in a static spacetime sourced by a nonlinear magnetic monopole immersed in a Hernquist dark-mat…
Josephson Effects in Slowly Rotating Spacetimes
Nurmukhammed Aytimbetov, Reggie C. Pantig, Ali Övgün +2
We investigate Josephson phenomena in a slowly rotating stationary spacetime, emphasizing the distinct roles of gravitational redshift and rotational frame dragging motivated by [1…
Gauss-Bonnet lensing of spinning massive particles in static spherically symmetric spacetimes
Reggie C. Pantig, Ali Övgün
We extend the finite-distance Jacobi-metric Gauss-Bonnet framework of Li \textit{et al}. [10.1103/PhysRevD.101.124058] to massive test particles carrying intrinsic spin. At pole-di…
Horizon-Brightened Acceleration Radiation and Optical Signatures of Generic Regular Black Holes from Nonlinear Electrodynamics
Uktamjon Uktamov, Ali Övgün, Reggie C. Pantig +1
We investigate horizon-brightened acceleration radiation (HBAR) and optical signatures for a broad class of regular black holes sourced by nonlinear electrodynamics. The spacetimes…
Radial Integral Reformulation of the Gauss-Bonnet Weak Deflection Angle at Finite Distance
Ali Övgün, Reggie C. Pantig
We develop a radial integral reformulation of finite distance gravitational lensing in optical geometry for static, spherically symmetric spacetimes. Starting from the Gauss-Bonnet…
Finite Distance Corrections to Vacuum Birefringence in Strong Gravitational and Electromagnetic Fields
Ali Övgün, Reggie C. Pantig
We study polarization dependent photon propagation in static, spherically symmetric spacetimes permeated by strong magnetic fields, with the aim of quantifying how finite emission…
Acceleration Radiation of Freely Falling Atoms: Nonlinear Electrodynamic Effects
Ali Övgün, Reggie C. Pantig, Bobomurat Ahmedov +1
Motivated by the work of Scully \textit{et al.} [ \textcolor{blue}{Proc. Nat. Acad. Sci. 115, 8131 (2018)}] and Camblong \textit{et al.}[ \textcolor{blue}{Phys. Rev. D 102, 085010…