Zero-frequency magnetic fluctuations in homogeneous cosmic plasma revisited

TL;DR

This paper revisits magnetic fluctuations in homogeneous cosmic plasma, providing more accurate calculations that challenge previous assumptions about spectral intensity independence from cutoff parameters.

Contribution

It offers a new, approximation-free calculation of magnetic fluctuations in cosmic plasma, highlighting their dependence on plasma and collisional frequencies.

Findings

Spectral intensity varies with cutoff parameter $k_{cut}$, contrary to previous claims.

Magnetic fluctuation intensity depends on plasma and collisional frequencies.

Results differ qualitatively and quantitatively from earlier studies.

Abstract

Magnetic fluctuations in a non-magnetized gaseous plasma is revisited and calculated without approximations, based on the fluctuation-dissipation theorem. It is argued that the present results are qualitative and quantitative different form previous one based on the same theorem. In particular, it is shown that it is not correct that the spectral intensity does not vary sensitively with $k_{cut}$. Also the simultaneous dependence of this intensity on the plasma and on the collisional frequencies are discussed.