Instability of a trapped ultracold Fermi gas with attractive   interactions : quantum effects
  We consider the possible mechanical instability of an ultracold Fermi gas due to the attractive interactions between fermions of different species. We investigate how the instability, predicted by a mean field calculation for an homogeneous system, is modified when the gas is trapped in a harmonic potential and quantum effects are included. 
X. Leyronas and R. Combescot