Vortex solitons - Mass, Energy and Angular momentum bunching in   relativistic electron-positron plasmas
  It is shown that the interaction of large amplitude electromagnetic waves with a hot electron-positron (e-p) plasma (a principal constituent of the universe in the MeV epoch) leads to a bunching of mass, energy, and angular momentum in stable, long-lived structures. Electromagnetism in the MeV epoch, then, could provide a possible route for seeding the observed large-scale structure of the universe. 
T. Tatsuno (1), V. I. Berezhiani (1), and S. M. Mahajan (2)   ((1)University of Tokyo, (2)University of Texas)