On the reliability of merger-trees and the mass growth histories of dark   matter haloes
  We have used merger trees realizations to study the formation of dark matter haloes. The construction of merger-trees is based on three different pictures about the formation of structures in the Universe. These pictures include: the spherical collapse (SC), the ellipsoidal collapse (EC) and the non-radial collapse (NR). The reliability of merger-trees has been examined comparing their predictions related to the distribution of the number of progenitors, as well as the distribution of formation times, with the predictions of analytical relations. The comparison yields a very satisfactory agreement. Subsequently, >......... 
N. Hiotelis (1), A. Del Popolo (2) ((1) 1st Experimental Lyceum of   Athens, Athens; (2) Bogazici university)