Time-dependent study of a black-hole laser in a flowing atomic condensate

We numerically study the temporal evolution of a black-hole laser configuration displaying a pair of black- and white-hole horizons in a flowing atomic condensate. This configuration is initially prepared starting from a homogeneous flow via a suitable space-dependent change of the interaction constant and the evolution is then followed up to long times. Depending on the values of the system parameters, the system typically either converges to the lowest-energy solution by evaporating away the horizons or displays a continuous and periodic coherent emission of solitons. By making a physical comparison with optical laser devices, we identify the latter regime of continuous emission of solitons as the proper black-hole laser effect.