We derive the wave–particle interaction time (IT) equation considering the effects of special relativity theory for whistler-mode chorus waves and relativistic electrons in Earth's radiation belt. Results show that IT has a non-linear dependence on the wave group velocity, electrons' energy, and initial pitch angle. Our results show that the interaction time is generally longer when applying the complete relativistic approach compared to a non-relativistic calculation.

We report an event where hiss wave intensity decreased, associated with the enhanced convection and a substorm. We suggest that the enhanced magnetospheric electric field causes the outward and sunward motion of energetic electrons. This leads to the decrease of energetic electron fluxes on the duskside, which provide free energy for hiss amplification. The study reveals the important role of magnetospheric electric field in the variation of the energetic electron flux and hiss wave intensity.

We present a new in situ observation of energetic electrons in space obtained by a newly available particle detector. In view of the characteristic signatures in the particle flux, we attribute the observational features to the drift-resonance wave–particle interaction between energetic electrons and multiple localized ultra-low-frequency waves. The scenario is substantiated by a numerical calculation based on the revised drift-resonance theory which reproduced the observed particle signatures.

Space plasmas are assumed to be highly active and dynamic systems including waves and turbulence. Electromagnetic waves such as Alfven waves interact with one another, producing daughter waves. In our study based on three-dimensional hybrid simulations, we emphasize the role of obliquely propagating daughter waves in particle heating in low-temperature (or low-beta) plasmas. The evolutions of plasma turbulence, wave dissipation, and heating are essential problems in astrophysics.