2009/01/15 by Ram Brustein, A. J. M. Medved
Earth and Planetary Sciences · Physics and Astronomy · #Acoustics #Black Holes and Theoretical Physics #Classical mechanics #Computer science #Constant (computer programming) #Cosmology and Gravitation Theories #Geophysics and Gravity Measurements #Physics #Sound (geography) #Theoretical physics #hep-th
paper · pdf · doi:10.1103/physrevd.79.126012
published as Phys.Rev.D79:126012,2009 · 24 pages
arxiv created 2009/01/15 · openalex publication_date 2009/06/19 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The near-horizon metric for a black brane in anti--de Sitter space and the metric near the AdS boundary both exhibit hydrodynamic behavior. We demonstrate the equivalence of this pair of hydrodynamic systems for the sound mode of a conformal theory. This is first established for Einstein's gravity, but we then show how the sound damping constant will be modified from its Einstein form for a generalized theory. The modified damping constant is expressible as the ratio of a pair of gravitational couplings that are indicative of the sound-channel class of gravitons. This ratio of couplings differs from both that of the shear diffusion coefficient and the shear viscosity to entropy ratio. Our analysis is mostly limited to conformal theories, but suggestions are made as to how this restriction might eventually be lifted.