Strong field double ionization : The phase space perspective
  We identify the phase-space structures that regulate atomic double ionization in strong ultrashort laser pulses. The emerging dynamical picture complements the recollision scenario by clarifying the distinct roles played by the recolliding and core electrons, and leads to verifiable predictions on the characteristic features of the "knee", a hallmark of the nonsequential process. 
Fran\c{c}ois Mauger, Cristel Chandre (CPT), Turgay Uzer