# Effective field theory of dissipative fluids (II): classical limit, dynamical KMS symmetry and entropy current

## Abstract

Here in this paper we further develop the fluctuating hydrodynamics proposed 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 Z2 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.

- Authors:

- Univ. of Chicago, IL (United States). Kadanoff Center for Theoretical Physics and Enrico Fermi Inst.
- Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Center for Theoretical Physics

- Publication Date:

- Research Org.:
- Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

- Sponsoring Org.:
- USDOE

- OSTI Identifier:
- 1430044

- Grant/Contract Number:
- FG02-05ER41360

- Resource Type:
- Journal Article: Accepted Manuscript

- Journal Name:
- Journal of High Energy Physics (Online)

- Additional Journal Information:
- Journal Name: Journal of High Energy Physics (Online); Journal Volume: 2017; Journal Issue: 9; Journal ID: ISSN 1029-8479

- Publisher:
- Springer Berlin

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; Effective Field Theories; Space-Time Symmetries; Quantum Dissipative Systems

### Citation Formats

```
Glorioso, Paolo, Crossley, Michael, and Liu, Hong.
```*Effective field theory of dissipative fluids (II): classical limit, dynamical KMS symmetry and entropy current*. United States: N. p., 2017.
Web. doi:10.1007/JHEP09(2017)096.

```
Glorioso, Paolo, Crossley, Michael, & Liu, Hong.
```*Effective field theory of dissipative fluids (II): classical limit, dynamical KMS symmetry and entropy current*. United States. doi:10.1007/JHEP09(2017)096.

```
Glorioso, Paolo, Crossley, Michael, and Liu, Hong. Wed .
"Effective field theory of dissipative fluids (II): classical limit, dynamical KMS symmetry and entropy current". United States.
doi:10.1007/JHEP09(2017)096. https://www.osti.gov/servlets/purl/1430044.
```

```
@article{osti_1430044,
```

title = {Effective field theory of dissipative fluids (II): classical limit, dynamical KMS symmetry and entropy current},

author = {Glorioso, Paolo and Crossley, Michael and Liu, Hong},

abstractNote = {Here in this paper we further develop the fluctuating hydrodynamics proposed 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 Z2 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.},

doi = {10.1007/JHEP09(2017)096},

journal = {Journal of High Energy Physics (Online)},

number = 9,

volume = 2017,

place = {United States},

year = {Wed Sep 20 00:00:00 EDT 2017},

month = {Wed Sep 20 00:00:00 EDT 2017}

}

*Citation information provided by*

Web of Science

Web of Science