Manifestations of the pseudogap in the BOSON-FERMION model for   Bose-Einstein condensation driven Superconductivity
  The normal state behaviour of the density of states of the electrons described by the BOSON - FERMION model for Bose-Einstein condensation driven superconductivity is characterized by the appearence of a pseudogap which developes into a true gap upon lowering the temperature and the superconducting critical temperature is approached. The consequences of this on the temperature dependence of the specific heat, the NMR relaxation rate and the optical conductivity is examined. 
J. Ranninger, J. M. Robin