Multidimensional instability of electron-acoustic solitary waves in a magnetized plasma with vortexlike electron distribution

The basic features of obliquely propagating electron-acoustic (EA) solitary waves and their multidimensional instability in a magnetized plasma containing cold electrons, hot electrons obeying a vortexlike distribution, and stationary ions have been theoretically investigated by the reductive perturbation method and small-k perturbation expansion technique. The combined effects of external magnetic field (obliqueness) and trapped electron distribution, which are found to significantly modify the basic properties (amplitude and width) of small but finite-amplitude EA solitary waves, are explicitly examined. It is also found that the instability criterion and the growth rate are significantly modified by the external magnetic field and the propagation directions of both the nonlinear waves and their perturbation modes. The implications of our results in space plasmas are briefly discussed. (C) 2008 American Institute of Physics. [DOI:10.1063/1.3006087]