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Free keywords:
Astrophysics, High Energy Astrophysical Phenomena, astro-ph.HE,General Relativity and Quantum Cosmology, gr-qc, Physics, Fluid Dynamics, physics.flu-dyn
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.
