44 papers
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…
LoKiFormer: Locality-aware Attention with Decoupled Knowledge Memory for Efficient Large Language Model Pretraining
Qiuwu Chen, Zimo Liu, Yuchen Li +8
Large language models (LLMs) have achieved remarkable breakthroughs across various applications. However, their architectures remain inefficient in pretraining due to two main limi…
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 Ãvgün, 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 Ãvgün, Reggie C. Pantig +1
The paper analyzes how the spin of a test particle affects its motion, orbital stability, and epicyclic frequencies around a non‑rotating (Schwarzschild) black hole, and explores i…