Séminaire D2 : Scattering of surface waves on an analogue black hole

Scott Robertson, post-doctorant, LAL Orsay, Université Paris-Sud
Lieu Evenemement: 
SP2MI, bâtiment H2, salle 175/177
Mardi, 29 Janvier, 2019 - 11:00

In Poitiers has been realized a stationary transcritical flow of water in a flume that possesses the analogue of a black hole horizon for long-wavelength surface waves. I will discuss the significance of this achievement within the field of Analogue Gravity. The horizon has been probed via the scattering of an incident co-current wave, which partially scatters into counter-current waves on either side of the horizon, yielding three outgoing waves (of which one has negative energy) rather than two in the absence of transcriticality. The measured analogue grey-body factor (i.e. the reflection coefficient) is in good agreement with the prediction of the non-dispersive theory, where the kinematical description in terms of an effective spacetime metric is exact. One also sees the emergence of characteristic peaks in the two-point correlation function of free surface deformations, one of which indicates the presence of a horizon and in quantum settings would be used to demonstrate the presence of the thermal analogue Hawking effect.


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