2025/09/21 by Maxim Lyutikov, Lyutikov, Maxim
Physics and Astronomy · #FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #Ionosphere and magnetosphere dynamics #Magnetic confinement fusion research #Plasma Physics (physics.plasm-ph) #Solar and Space Plasma Dynamics
paper · pdf · doi:10.48550/arxiv.2509.17245
openalex publication_date 2025/09/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Using a two-fluid approach, we consider the properties of relativistically nonlinear (arbitrary a0), circularly polarized \EM waves propagating along magnetic field in electron-ion and pair plasmas. Dispersion relations depend on how wave intensity scales with frequency, a0 (ω). For superluminal branches, the nonlinear effects reduce the cut-off frequency, while the general form of the dispersion relations ω(k) remains similar to the linear case. For subluminal waves, whistlers and Alfven, a new effect appears: dispersion curves effectively terminate at finite ω^∗ - k^∗, where the group velocity becomes zero. Qualitatively, subluminal modes with fluctuating electric field larger than the guide field, Ew (ω) ≥ B0, cannot propagate. In extended systems, e.g., within magnetospheres of neutron stars, this leads to opening of the magnetosphere by a strong wave.