2017/01/31 by Paolo Glorioso, Michael Crossley, Hong Liu · 112 citations
Mathematics · Physics and Astronomy · #Black Holes and Theoretical Physics #Conformal field theory #Conformal map #Conformal symmetry #Dissipative system #Effective action #Effective field theory #Entropy (arrow of time) #High-Energy Particle Collisions Research #Invariant (physics) #Quantum many-body systems #Spacetime #cond-mat.stat-mech #gr-qc #hep-ph #hep-th #math-ph #math.MP
paper · pdf · doi:10.1007/jhep09(2017)096
published in Journal of High Energy Physics 2017(9) (Springer Nature) · 49+8 pages, 1 figure. v2: references added, minor clarifications
openalex created_date 2017/02/10 · arxiv created 2017/02/24 · openalex publication_date 2017/09/01 · arxiv updated 2017/10/25 · openalex updated_date 2026/08/05
In this paper we further develop the fluctuating hydrodynamics proposed in [1] in a number of ways. We first work out in detail the classical limit of the hydrodynamical action, which exhibits many simplifications. In particular, this enables a transparent formulation of the action in physical spacetime in the presence of arbitrary external fields. It also helps to clarify issues related to field redefinitions and frame choices. We then propose that the action is invariant under a Z 2 symmetry to which we refer as the dynamical KMS symmetry. The dynamical KMS symmetry is physically equivalent to the previously proposed local KMS condition in the classical limit, but is more convenient to implement and more general. It is applicable to any states in local equilibrium rather than just thermal density matrix perturbed by external background fields. Finally we elaborate the formulation for a conformal fluid, which contains some new features, and work out the explicit form of the entropy current to second order in derivatives for a neutral conformal fluid.