Seminar of the Applied Physics Scientific Section

2011 Academic Year

Thursday, 20 January 2011

Time: 15.30

Oppenheimer Meeting Room, Second Floor, Leonardo Building



Measurement of stimulated Hawking emission in an analogue system (*)


Silke Weinfurtner,
SISSA, Trieste


(*) Summary. There is a mathematical analogy between the propagation of fields in a general relativistic space-time and long (shallow water) surface waves on moving water. Hawking argued that black holes emit thermal radiation via a quantum spontaneous emission. Similar arguments predict the same effect near wave horizons in fluid flow. By placing a streamlined obstacle into an open channel flow we create a region of high velocity over the obstacle that can include wave horizons. Long waves propagating upstream towards this region are blocked and converted into short (deep water) waves. This is the analogue of the stimulated emission by a white hole (the time inverse of a black hole), and our measurements of the amplitudes of the converted waves demonstrate the thermal nature of the conversion process for this system. Given the close relationship between stimulated and spontaneous emission, our findings attest to the generality of the Hawking process.

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(**) Biodata: Dr. Silke Weinfurtner from the Astrophysics Sector of SISSA, Trieste obtained her PhD  at Victoria University of Wellington, New Zealand. Then she was a  Postdoctoral Research Fellow at the University of British Columbia (Canada) in the Department of Physics and Astronomy.

    At present she has an invitation to join the Foundational Questions Institute that explores the foundations and boundaries of physics and cosmology aiming at deeper understanding of reality, a significant philosophical question that is generally neglected.

     In 2004 she received the Hartle Prize of the International Society on General Relativity and Gravitation, given for the best student presentation at the 17th International Conference on General Relativity and Gravitation in Ireland. More recently ”Cosmological particle production in emergent rainbow spacetimes” has been selected by the Editorial Board of Classical and Quantum Gravity (CQG) as part of the journal’s Highlights of 2008 and 2009.

    She has a considerable list of publications in peer-review journals, recent results of which she will discuss in her seminar, especially the results in the frontier between general relativity and fluid dynamics.