2008/10/31 by Evgeny I. Buchbinder, Evgeny I Buchbinder, Alex Buchel +2 · 2 citations
Mathematics · Physics and Astronomy · #Acoustic attenuation #Attenuation #Black Holes and Theoretical Physics #Computation #Conformal map #Dispersion (optics) #Duality (order theory) #Geometry and complex manifolds #Holography #Magnetic field #Quantum Electrodynamics and Casimir Effect #Supergravity #hep-th
paper · pdf · doi:10.1088/1126-6708/2008/12/090
published as JHEP 12 (2008) 090 · 32 pages, LaTeX; minor corrections, references added; an error in the boundary conditions fixed, a slight change in the results
arxiv created 2008/12/22 · openalex publication_date 2008/12/22 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We use the AdS/CFT correspondence to study propagation of sound waves in strongly coupled (2+1) dimensional conformal magnetic fluids. Our computation provides a nontrivial consistency check of the viscous magneto-hydrodynamics of Hartnoll-Kovtun-Muller-Sachdev to leading order in the external field. Depending on the behavior of the magnetic field in the hydrodynamic limit, we show that it can lead to further attenuation of sound waves in the (2+1) dimensional conformal plasma, or reduce the speed of sound. We present both field theory and dual supergravity descriptions of these phenomena. While to the leading order in momenta the dispersion of the sound waves obtained from the dual supergravity description agrees with the one predicted from field theory, we find a discrepancy at higher order. This suggests that further corrections to HKMS magneto-hydrodynamics are necessary.