Coherent electromagnetic structures in relativistic plasmas

Relativistic electromagnetic low-frequency solitary waves are found to occu r in underdense plasmas in regimes where the laser pulse becomes filamented and undergoes energy depletion and frequency downshifting. These slowly pr opagating "subcycle-solitons" represent one of the channels of conversion o f the laser pulse energy. Electron vortices and their associated quasistati c magnetic field represent a different important type of long lived coheren t electromagnetic structures. Their generation is related to the dynamics o f fast electron currents in the plasma.