The Gravitational Bending of Acoustic Schwarzschild Black Hole

Acoustic black hole is becoming an attractive topic in recent years, for it open-up new direction for experimental explorations of black holes in laboratories. In this work, the gravitational bending of acoustic Schwarzschild black hole is investigated. We resort to the approach developed by Gibbons and Werner, in which the gravitational bending is calculated using the Gauss-Bonnet theorem in geometrical topology. In this approach, the gravitational bending is directly connected with the topological properties of curved spacetime. The deflection angle of light for acoustic Schwarzschild black hole is calculated and carefully analyzed in this work. The results show that the gravitational bending effect in acoustic black hole is enhanced, compared with those in conventional Schwarzschild black hole. This observation indicates that the acoustic black holes may be more easily detectable in gravitational bending and weak gravitational lensing observations. Keywords: Gravitational Bending; Gauss-Bonnet Theorem; Acoustic Schwarzschild Black Hole