Light deflection and gravitational lensing effects in acoustic black-bounce spacetime

TL;DR

This paper investigates how light deflection and gravitational lensing behave in acoustic black-bounce spacetimes, comparing weak and strong field regimes and relating theoretical models to potential observations.

Contribution

It provides analytical expressions for light deflection in acoustic black-bounce spacetimes, a novel approach linking these models to observational data.

Findings

Analytical formulas for light deflection in both regimes.

Differences between acoustic black-bounce and Schwarzschild lensing.

Potential observational signatures of acoustic black-bounce spacetimes.

Abstract

In the present work, we analyze the gravitational deflection for a light beam in the weak and strong field regimes for the gravitational analogue geometry of an acoustic black hole (ABH) and acoustic black-bounce (ABB). Motivationally, the first spacetime arises as an exact solution of the field equations for gravitational black holes (BHs) in an Einstein-scalar-Gauss-Bonnet theory (EsGB) \cite{3}. In contrast, the second model arises from the combination of phantom scalar field and nonlinear electrodynamics in general relativity (GR) \cite{INTRO24}. We construct analytical expressions for the angular deflection of light in both limits and, from them, analyze the construction of the observables, which allow us to relate theoretical models to observational data. We compare these observables and show how much they differ from those obtained in the Schwarzschild solution.