@article{96a6945370eb4d04b69eb9e34eccf5d4,
title = "Hydrodynamic modes of homogeneous and isotropic fluids",
abstract = "Relativistic fluids are Lorentz invariant, and a non-relativistic limit of such fluids leads to the well-known Navier–Stokes equation. However, for fluids moving with respect to a reference system, or in critical systems with generic dynamical exponent z, the assumption of Lorentz invariance (or its non-relativistic version) does not hold. We are thus led to consider the most general fluid assuming only homogeneity and isotropy and study its hydrodynamics and transport behaviour. Remarkably, such systems have not been treated in full generality in the literature so far. Here we study these equations at the linearized level. We find new expressions for the speed of sound, corrections to the Navier–Stokes equation and determine all dissipative and non-dissipative first order transport coefficients. Dispersion relations for the sound, shear and diffusion modes are determined to second order in momenta. In the presence of a scaling symmetry with dynamical exponent z, we show that the sound attenuation constant depends on both shear viscosity and thermal conductivity.",
author = "\{De Boer\}, Jan and Jelle Hartong and Obers, \{Niels A.\} and Watse Sybesma and Stefan Vandoren",
note = "Funding Information: We thank Alexander Abanov, Jay Armas, Blaise Gout{\'e}raux, Elias Kiritsis, Koenraad Schalm, Henk Stoof and L{\'a}rus Thorlacius for useful discussions. We especially thank Sa{\v s}o Grozdanov and Kristan Jensen for careful reading of this manuscript and for the many useful discussions. All the authors thank Nordita for hospitality and support during the 2016 workshop “Black Holes and Emergent Spacetime”. The work of NO is supported in part by the project “Towards a deeper understanding of black holes with non-relativistic holography” of the Independent Research Fund Denmark (grant number DFF-6108-00340). JH and NO gratefully acknowledge support from the Simons Center for Geometry and Physics, Stony Brook University at which some of the research for this paper was performed during the 2017 workshop “Applied Newton-Cartan Geometry”. JH acknowledges hospitality of the Niels Bohr Institute and NO acknowledges hospitality of the Universities of Amsterdam and Utrecht during part of this work. This work was further supported by the Netherlands Organisation for Scientific Research (NWO) under the VICI grant 680-47-603, and the Delta-Institute for Theoretical Physics (D-ITP) that is funded by the Dutch Ministry of Education, Culture and Science (OCW). Publisher Copyright: Copyright J. de Boer et al.",
year = "2018",
month = aug,
doi = "10.21468/SciPostPhys.5.2.014",
language = "English",
volume = "5",
journal = "SciPost Physics",
issn = "2542-4653",
publisher = "SciPost Foundation",
number = "2",
}