Universality and intermittency in relativistic turbulent flows of a hot plasma

TL;DR

This study uses high-order numerical simulations to analyze relativistic turbulence in hot plasmas, revealing that relativistic effects enhance intermittency and high-order statistical deviations while preserving classical low-order turbulence features.

Contribution

It provides the most accurate simulations to date of driven relativistic turbulence, highlighting the impact of relativistic effects on intermittency and statistical properties.

Findings

Relativistic effects significantly increase flow intermittency.

Low-order statistics remain universal and align with Kolmogorov theory.

High-order statistics and intermittency are notably affected by relativistic dynamics.

Abstract

With the aim of determining the statistical properties of relativistic turbulence and unveiling novel and non-classical features, we resent the results of direct numerical simulations of driven turbulence in an ultrarelativistic hot plasma using high-order numerical schemes. We study the statistical properties of flows with average Mach number ranging from $\sim 0.4$ to $\sim 1.7$ and with average Lorentz factors up to $\sim 1.7$. We find that flow quantities, such as the energy density or the local Lorentz factor, show large spatial variance even in the subsonic case as compressibility is enhanced by relativistic effects. The velocity field is highly intermittent, but its power-spectrum is found to be in good agreement with the predictions of the classical theory of Kolmogorov. Overall, our results indicate that relativistic effects are able to significantly enhance the intermittency of the flow and affect the high-order statistics of the velocity field, while leaving unchanged the low-order statistics, which instead appear to be universal and in good agreement with the classical Kolmogorov theory. To the best of our knowledge, these are the most accurate simulations of driven relativistic turbulence to date.