Statistical characterization of the collective synchrotron radiation power emitted by non-ideal magnetized plasma fluids in relativistic jets.

This article focuses on the statistical kinetic analysis of collective synchrotron radiation power emitted by non-ideal magnetized plasma fluids at kinetic equilibrium in relativistic astrophysical jets. It develops a covariant kinetic theory framework yielding a non-isotropic equilibrium kinetic distribution function (KDF) expressed as a Gaussian-like solution dependent on particle adiabatic invariants, notably including the relativistic magnetic moment conserved in collisionless plasmas. This non-isotropic KDF differs from the isotropic Juttner distribution by incorporating velocity-space anisotropies that lead to non-ideal fluid properties such as pressure anisotropy and a tensorial equation of state. Using a Chapman–Enskog series expansion around the Juttner distribution, the study analytically calculates the ensemble-averaged synchrotron power, demonstrating that it exhibits both quadratic and linear power-law dependences on the background magnetic field magnitude, as well as a complex dependence on plasma temperature. The results suggest that these statistical discrepancies in synchrotron emission could provide an independent diagnostic tool for characterizing the physical state of relativistic plasma jets and their permeating magnetic fields.