Analogizing the ergosphere of a rotating black hole with pilot-wave hydrodynamics

The pilot-wave hydrodynamic system discovered by Yves Couder in 2005 has provided a platform for analogizing many microscopic, quantum systems. We here demonstrate its value in analogizing the dynamics of particles on astronomical scales, specifically the motion of photons in the vicinity of a rotating black hole. A notable feature of this atronomical system is that photons may execute orbits around the black hole in a finite range of radii known as the ergosphere. We consider self-propelling droplets on a vibrating bath approaching a stationary vortex forced by a submerged rotor, and build upon the existing analogical basis of gravitoelectromagnetism. The curved interface plays the role of the spacetime curvature n the vicinity of the black hole, the rotating free surface the role of the gravito-Lorentz force. The system extends the analogical range of pilot-wave hydrodynamics from atomic to astronomical scales, a range spanning approximately 30 orders of magnitudes.