Backreaction in an Analogue Black Hole Experiment

Area of Science:

• Fluid dynamics
• Analogue gravity
• Black hole physics

Background:

• Analogue models, especially fluid mechanical ones, effectively mimic black hole phenomena.
• Hydrodynamic black holes are typically externally driven, lacking significant internal backreaction.
• Previous models assumed experimental parameters solely determined mass and angular momentum.

Purpose of the Study:

• To investigate the phenomenon of backreaction in finite-sized analogue black hole systems.
• To explore if fluid systems exhibit internal responses to wave dynamics.
• To determine if this backreaction can be quantified and studied.

Main Methods:

• Utilizing a rotating draining vortex flow as a fluid analogue black hole.
• Observing the system's response to the presence of waves.
• Measuring changes in the system's total mass over time.

Main Results:

• A finite-sized fluid system demonstrated a significant global change in total mass.
• This mass change occurred on timescales longer than the wave dynamics.
• The observed backreaction was successfully encapsulated by a dynamical metric.

Conclusions:

• Fluid analogue black holes exhibit non-negligible internal backreaction.
• This backreaction significantly alters the system's total mass.
• Analogue spacetimes offer a novel platform for investigating black hole backreaction effects.