Constraint on initial conditions of one-dimensional expanding fluids from nonlinear causality

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Hoshino, Tau, Hirano, Tetsufumi
Formato: Preprint
Publicado: 2024
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866916591622422528
author Hoshino, Tau
Hirano, Tetsufumi
author_facet Hoshino, Tau
Hirano, Tetsufumi
contents The initial conditions of one-dimensional expanding viscous fluids in relativistic heavy-ion collisions are scrutinized in terms of nonlinear causality of the relativistic hydrodynamic equations. Conventionally, it is believed that the matter generated in relativistic heavy-ion collisions starts to behave as a fluid all at once at some initial time. However, it is by no means trivial how soon after the first contact of two high-energy nuclei the fluid picture can be applied. It is demonstrated that one-dimensional expanding viscous fluids violate the necessary and the sufficient conditions of nonlinear causality at large departures from local equilibrium. We therefore quantify the inverse Reynolds number to justify the hydrodynamic description to be valid. The initial conditions are strictly constrained not to violate the causality conditions during the time evolution. With the help of the transverse energies per rapidity measured at RHIC and LHC, we obtain the minimum initial proper time and the maximum energy density allowed by nonlinear causality. This analysis strongly suggests that the initial stage of relativistic heavy-ion collisions needs to be described by a non-equilibrium description other than the framework of relativistic dissipative hydrodynamics.
format Preprint
id arxiv_https___arxiv_org_abs_2412_02405
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Constraint on initial conditions of one-dimensional expanding fluids from nonlinear causality
Hoshino, Tau
Hirano, Tetsufumi
Nuclear Theory
High Energy Physics - Phenomenology
Nuclear Experiment
The initial conditions of one-dimensional expanding viscous fluids in relativistic heavy-ion collisions are scrutinized in terms of nonlinear causality of the relativistic hydrodynamic equations. Conventionally, it is believed that the matter generated in relativistic heavy-ion collisions starts to behave as a fluid all at once at some initial time. However, it is by no means trivial how soon after the first contact of two high-energy nuclei the fluid picture can be applied. It is demonstrated that one-dimensional expanding viscous fluids violate the necessary and the sufficient conditions of nonlinear causality at large departures from local equilibrium. We therefore quantify the inverse Reynolds number to justify the hydrodynamic description to be valid. The initial conditions are strictly constrained not to violate the causality conditions during the time evolution. With the help of the transverse energies per rapidity measured at RHIC and LHC, we obtain the minimum initial proper time and the maximum energy density allowed by nonlinear causality. This analysis strongly suggests that the initial stage of relativistic heavy-ion collisions needs to be described by a non-equilibrium description other than the framework of relativistic dissipative hydrodynamics.
title Constraint on initial conditions of one-dimensional expanding fluids from nonlinear causality
topic Nuclear Theory
High Energy Physics - Phenomenology
Nuclear Experiment
url https://arxiv.org/abs/2412.02405