Gravitational Lensing and Topological Photon Sphere of Holonomy Corrected Schwarzschild Black Hole with a Cloud of Strings

Faizuddin Ahmed, Shubham Kala

Published: 2025/9/9

Abstract

In this paper, we theoretically investigate the deflection of light, lensing equations, topological properties of photon rings, and accretion disk characteristics in the spacetime of a holonomy-corrected Schwarzschild black hole surrounded by a cloud of strings. The analysis is carried out in the weak-field limit, where we analytically derive expressions for the deflection angle and extract the corresponding lensing observables. These results reveal the dependence of light deflection on the string cloud parameter and the holonomy correction parameter, offering potential observational signatures of underlying quantum gravity effects. We model possible gravitational scenarios to explore the distinguishing features of this modified BH geometry and assess its deviation from classical solutions through gravitational lensing behavior. Furthermore, we analyze the topological structure of the photon sphere by constructing a normalized vector field and demonstrate how it is affected by the presence of string clouds and holonomy corrections. Finally, we examine the properties of a thin accretion disk in this BH background, showing that both the string cloud and holonomy parameters significantly influence the disk's radiation profile, temperature distribution, and spectral characteristics. Our results suggest that these modifications leave measurable imprints, providing viable avenues for observational constraints in the strong-gravity regime.

Gravitational Lensing and Topological Photon Sphere of Holonomy Corrected Schwarzschild Black Hole with a Cloud of Strings | SummarXiv | SummarXiv