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arXiv · 2209.10574

A Gauge Theory for Shallow Water

David Tong
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Abstract

The shallow water equations describe the horizontal flow of a thin layer of fluid with varying height. We show that the equations can be rewritten as a d=2+1 dimensional gauge theory with a Chern-Simons term. The theory contains two Abelian gauge fields, corresponding to the conserved height and conserved vorticity of the fluid. In a certain linearised approximation, the shallow water equations reduce to relativistic Maxwell-Chern-Simons theory. This describes Poincar\'e waves. The chiral edge modes of the theory are identified as coastal Kelvin waves.

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David Tong. 2022-09-21. A Gauge Theory for Shallow Water. https://doi.org/10.21468/scipostphys.14.5.102

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