Rotating curved spacetime signatures from a giant quantum vortex.

Gravity simulators are laboratory systems in which small excitations such as sound or surface waves behave as fields propagating on a curved spacetime geometry. The analogy between gravity and fluids requires vanishing viscosity, a feature naturally realized in superfluids such as liquid helium or cold atomic clouds. Such systems have been successful in verifying key predictions of quantum field theory in curved spacetime.

Quasinormal Modes of Optical Solitons.

Quasinormal modes (QNMs) are essential for understanding the stability and resonances of open systems, with increasing prominence in black hole physics. We present here the first study of QNMs of optical potentials. We show that solitons can support QNMs, deriving a soliton perturbation equation and giving exact analytical expressions for the QNMs of fiber solitons.

Backreaction in an Analogue Black Hole Experiment.

Analogue models of gravity, particularly fluid mechanical analogues, have been very successful in mimicking the behavior of fields around black holes. However, hydrodynamic black holes are externally driven systems whose effective mass and angular momentum are set by experimental parameters, and, as such, no appreciable internal backreaction is expected to take place. On the contrary, we show using a rotating draining vortex flow that a fluid system of finite size responds to the presence of waves on timescales much longer than the wave dynamics, which leads to a significant global change in the total mass of our system.

Quasinormal Mode Oscillations in an Analogue Black Hole Experiment.

The late stages of the relaxation process of a black hole are expected to depend only on its mass and angular momentum and not on the details of its formation process. Inspired by recent analogue gravity experiments, which demonstrate that certain black hole processes take place in gravitational and hydrodynamical systems alike, we conduct an experiment to search for quasinormal mode oscillations of the free surface of a hydrodynamical vortex flow. Our results demonstrate the occurrence and hint at the ubiquity of quasinormal ringing in nonequilibrium analog black hole experiments.

Black Hole Quasibound States from a Draining Bathtub Vortex Flow.

Quasinormal modes are a set of damped resonances that describe how an excited open system is driven back to equilibrium. In gravitational physics these modes characterize the ringdown of a perturbed black hole, e.g.