Examining electron-boson coupling using time-resolved spectroscopy
  Nonequilibrium pump-probe time domain spectroscopies can become an important tool to disentangle degrees of freedom whose coupling leads to broad structures in the frequency domain. Here, using the time-resolved solution of a model photoexcited electron-phonon system we show that the relaxational dynamics are directly governed by the equilibrium self-energy so that the phonon frequency sets a window for "slow" versus "fast" recovery. The overall temporal structure of this relaxation spectroscopy allows for a reliable and quantitative extraction of the electron-phonon coupling strength without requiring an effective temperature model or making strong assumptions about the underlying bare electronic band dispersion. 
Michael Sentef, Alexander F. Kemper, Brian Moritz, James K. Freericks,   Zhi-Xun Shen, Thomas P. Devereaux
cond-mat.other physics.comp-ph