activity
20242026
collaborators

20 papers

gr-qc2026

Particle dynamics and quasi-periodic oscillations of a Reissner--Nordström-like black hole in Kalb--Ramond gravity under an external magnetic test field

Faizuddin Ahmed, Ahmad Al-Badawi, Sardor Murodov +2

We investigate the dynamics of charged test particles and quasi-periodic oscillations around a Reissner--Nordström-like black hole in Kalb--Ramond (KR) gravity in the presence of…

gr-qc2026

MCMC Constraints on Dyonic Kalb-Ramond Black Holes with a Cloud of Strings from Twin-Peak QPOs and EHT Shadows

Faizuddin Ahmed, Ahmad Al-Badawi, İzzet Sakallı

We study a dyonic black hole in a Lorentz-violating gravity that carries a background Kalb--Ramond field and is pierced by a cloud of strings. The resulting metric reduces to the r…

gr-qc2026

Are Petrov type-N and D spacetimes admitting CTCs valid in gravity?

Faizuddin Ahmed, Ahmad Al-Badawi, İzzet Sakallı

We ask whether two classical time-machine geometries, the Ori (2005) compact-vacuum-core metric and the Ahmed (2018) four-dimensional generalisation of Misner space, remain admissi…

gr-qc2026

Transfer observables of rotating acoustic black holes from ray tracing: shadow centroid, redshift asymmetry and flux imbalance

Faizuddin Ahmed, Ahmad Al-Badawi, Fernando M. Belchior +1

We construct an impact-parameter-resolved transfer framework for null acoustic rays in the rotating draining-bathtub spacetime. The formalism separates the source-independent ray g…

gr-qc2026

Particle Dynamics, Shadow and Hawking Sparsity of a Kalb-Ramond Black Hole Coupled to Nonlinear Electrodynamics

Faizuddin Ahmed, Ahmad Al-Badawi, İzzet Sakallı

We study the timelike and null geodesic structure of a static, spherically symmetric black hole sourced by a Kalb--Ramond (KR) field coupled to nonlinear electrodynamics (NED). The…

gr-qc2026

Thermodynamics and optical aspects of ModMax black holes in higher order curvature gravity with quintessence dark energy

Ahmad Al-Badawi, Usman Zafar, Abdul Jawad +1

In this work, we derive an exact black hole solution in higher-order curvature gravity by coupling an electromagnetic sector formulated within the ModMax framework to a quintessenc…