Astrophysical Constraints on Charged Black Holes in Scalar--Tensor--Vector Gravity

TL;DR

This paper investigates charged black holes within Scalar-Tensor-Vector Gravity (STVG), revealing how parameters like $oldsymbol{ extit{ extalpha}}$ and charge $oldsymbol{Q}$ influence stability, light deflection, shadows, thermodynamics, and observational signatures, offering testable predictions.

Contribution

It provides a comprehensive analysis of charged black holes in STVG, highlighting new effects on stability, lensing, shadows, thermodynamics, and observational signatures not previously detailed.

Findings

$oldsymbol{ extalpha}$ enhances thermal stability and light deflection.

Charge $oldsymbol{Q}$ weakens stability and reduces light deflection.

Certain $oldsymbol{ extalpha}$ and $oldsymbol{Q}$ combinations mimic Kerr black hole signatures.

Abstract

We explore charged black holes in Scalar-Tensor-Vector Gravity (STVG), unveiling their distinctive features across multiple physical domains. Our topological analysis reveals that the STVG coupling parameter $\alpha$ bolsters thermal stability while electromagnetic charge $Q$ weakens it. Using the Gauss-Bonnet theorem, we find that $\alpha$ amplifies light deflection and enlarges shadow silhouettes, with $Q$ generating opposite effects. Our quantum-corrected models with exponential entropy terms pinpoint phase transitions in the microscopic regime, modifying conventional thermodynamic relationships. Calculations of strong gravitational lensing, shadow geometry, and Hawking emission show clear STVG signatures that diverge from Einstein's predictions. Notably, our accretion disk analysis uncovers an intriguing phenomenon: specific combinations of $\alpha$ and $Q$ can produce radiation patterns resembling spinning Kerr black holes, creating potential identification challenges for observers. These findings establish concrete observational tests for STVG theory through next generation astronomical imaging and lensing campaigns. By connecting theoretical predictions to measurable quantities, we outline specific pathways to confirm or constrain STVG using data from current and future space telescopes.