Horizon effects with surface waves on moving water
Abstract
Surface waves on a stationary flow of water are considered, in a linear model that includes the surface tension of the fluid. The resulting gravity-capillary waves experience a rich array of horizon effects when propagating against the flow. In some cases three horizons (points where the group velocity of the wave reverses) exist for waves with a single laboratory frequency. Some of these effects are familiar in fluid mechanics under the name of wave blocking, but other aspects, in particular waves with negative co-moving frequency and the Hawking effect, were overlooked until surface waves were investigated as examples of analogue gravity [Sch\"utzhold R and Unruh W G 2002 Phys. Rev. D 66 044019]. A comprehensive presentation of the various horizon effects for gravity-capillary waves is given, with emphasis on the deep water/short wavelength case kh>>1 where many analytical results can be derived. A similarity of the state space of the waves to that of a thermodynamic system is pointed out.
Cite
@article{arxiv.1004.5546,
title = {Horizon effects with surface waves on moving water},
author = {Germain Rousseaux and Philippe Maissa and Christian Mathis and Pierre Coullet and Thomas G. Philbin and Ulf Leonhardt},
journal= {arXiv preprint arXiv:1004.5546},
year = {2015}
}
Comments
30 pages, 15 figures. Minor changes