45 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…
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…
Spinning Particle Dynamics and Observational Redshift around an Asymptotically Flat Symmergent Black Hole
Beyhan Puliçe, Ali Övgün
We investigate timelike particle dynamics, collision energetics, and photon frequency shifts in the perturbative variable-scalar curvature branch of asymptotically flat symmergent…
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…
Shadow of the generalized Vaidya black hole
Vitalii Vertogradov, Ali Ãvgün
In this paper, we investigate the shadow of the generalized Vaidya black hole described by the Husain solution. Assuming a barotropic equation of state for the additional matter se…