Shear viscosity from fluctuations in linearized relativistic hydrodynamics
Abstract
In this work we incorporate thermal fluctuations into fluid-dynamic simulations with the vHLLE code, in linear approximation. The fluctuations are built in following the fluctuation-dissipation theorem. The effect of space discretization into cells in numerical hydrodynamics on the spatial correlation of fluctuations is studied with the help of static structure factor. A difference from the continuum result is pointed out and systematically investigated. Time evolution of the ensuing fluctuations is examined and the Green-Kubo formula is used for the extraction of shear viscosity from the fluctuations. The extracted value is demonstrated to be the same as the input value of the shear viscosity for the simulations using Israel-Stewart equations. It is also shown that numerical regulators commonly used in the codes to ensure stability of the calculation severely spoil the fluctuations and break the fluctuation-dissipation theorem.
Related
- Effective shear viscosity from the friction term in relativistic multi-fluid hydrodynamics
- Maxwell-Jüttner averaged nonaffine theory of relativistic shear viscosity
- Quantum fluctuations in hydrodynamics and quantum long-time tails
- Regularization of stochastic fluid dynamics and non-perturbative renormalization of the shear viscosity of incompressible fluids
- Levy-shaped femtoscopic sources from an exact solution of relativistic hydrodynamics
BibTeX
@misc{sterba2026shear,
title = {{Shear viscosity from fluctuations in linearized relativistic hydrodynamics}},
author = {Jakub Sterba and Iurii Karpenko and Marlene Nahrgang and Boris Tomasik},
howpublished = {HAL},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.18554},
eprint = {2610.18554},
archivePrefix = {arXiv},
url = {https://hal.science/hal-05842364v1},
}
RIS
TY - UNPB
TI - Shear viscosity from fluctuations in linearized relativistic hydrodynamics
AU - Jakub Sterba
AU - Iurii Karpenko
AU - Marlene Nahrgang
AU - Boris Tomasik
PY - 2026
DA - 2026/10/13
PB - HAL
DO - 10.48550/arxiv.2610.18554
UR - https://hal.science/hal-05842364v1
AB - In this work we incorporate thermal fluctuations into fluid-dynamic simulations with the vHLLE code, in linear approximation. The fluctuations are built in following the fluctuation-dissipation theorem. The effect of space discretization into cells in numerical hydrodynamics on the spatial correlation of fluctuations is studied with the help of static structure factor. A difference from the continuum result is pointed out and systematically investigated. Time evolution of the ensuing fluctuations is examined and the Green-Kubo formula is used for the extraction of shear viscosity from the fluctuations. The extracted value is demonstrated to be the same as the input value of the shear viscosity for the simulations using Israel-Stewart equations. It is also shown that numerical regulators commonly used in the codes to ensure stability of the calculation severely spoil the fluctuations and break the fluctuation-dissipation theorem.
ER -