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Observation of Noise Correlated by the Hawking Effect in a Water Tank
L-P Euvé1, F Michel2, R Parentani2
1Institut Pprime, UPR 3346, CNRS-Université de Poitiers-ISAE ENSMA 11 Boulevard Marie et Pierre Curie-Téléport 2, BP 30179, 86962 Futuroscope Cedex, France.
Abstract:
We measured the power spectrum and two-point correlation function for the randomly fluctuating free surface on the downstream side of a stationary flow with a maximum Froude number F_{max}≈0.85 reached above a localized obstacle. On such a flow the scattering of incident long wavelength modes is analogous to that responsible for black hole radiation (the Hawking effect). Our measurements of the noise show a clear correlation between pairs of modes of opposite energies. We also measure the scattering coefficients by applying the same analysis of correlations to waves produced by a wave maker.
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