Criteria of amorphous solidification
  A different perspective on the long-standing problem of amorphous solidification is offered, based on an alternative definition of a solid as a porous medium. General, model-free results are obtained concerning the growing dynamic length accompanying solidification and its relation to the growing relaxation time. Criteria are derived for the dynamic length to diverge and for its divergence to entail the arrest of particle motion. 
Haim Diamant
cond-mat.dis-nn cond-mat.soft