Memory and correlation effects in the exciton-phonon kinetics
  Memory and correlation effects in the interband absorption from quantum wells due to exciton-phonon dynamics are investigated. They are traced back to the frequency dependence and matrix character of the self energy arising in a 2nd Born theory. It is found that interpeak absorption increases with respect to the case in which this memory and correlation effects are neglected. 
G. Mannarini, R. Zimmermann