New Insights into Black Hole Deflection and Shadow Size from Recent Research

In a recent paper titled "On the analytic generalization of particle deflection in the weak field regime and shadow size in light of EHT constraints for Schwarzschild-like black hole solutions," author Reggie C. Pantig presents significant advancements in understanding black hole physics. The paper, submitted to arXiv on August 31, 2024, introduces an analytic generalization of the weak field deflection angle (WDA) using the Gauss-Bonnet theorem. This generalization applies to any Schwarzschild-like spacetime, which includes variations from the classical Schwarzschild case through specific parameters.

The findings include four examples related to bumblebee gravity theory and one concerning a black hole surrounded by soliton dark matter. The results show a mix of new insights and confirmations of existing literature. Notably, the WDA formula allows for straightforward calculations, enabling approximations under certain conditions without needing preliminary steps.

Additionally, the study explores how the shadow size of a black hole is influenced solely by the parameter associated with the metric coefficient in the time coordinate. A general formula for this constrained parameter is derived based on observational results from the Event Horizon Telescope (EHT).

The implications of this work extend to potential generalizations for other black hole models, including Reissner-Nordström-like and de Sitter/Anti-de Sitter-like black holes, as well as higher-dimensional black hole solutions. These advancements could enhance our understanding of black hole characteristics and their observational signatures, contributing to the broader field of astrophysics and cosmology.