Percolation and nucleation approaches to nuclear fragmentation. Criticality in very small systems

Different criteria for criticality in very small systems are discussed in the context of percolation and nucleation approaches to nuclear fragmentation. It is shown that the probability threshold in percolation and the interaction radius threshold in nucleation are very strongly dependent upon the adopted criterion. Similarities and dissimilarities between nucleation and percolation pictures are also pointed out. (author)