Gravitational collapse and non-self similarity in the L-T relation
  We derive the luminosity-temperature relation for clusters of galaxies by means of a modification of the self-similar model to take account of angular momentum acquisition by protostructures and of an external pressure term in the virial theorem. The fundamental result of the model is that gravitational collapse, which takes account of angular momentum acquisition, can explain the non self-similarity in the L-T relation, in disagreement with the largely accepted assumption that heating/cooling processes and similar are fundamental in the originating the non-self similar behavior (shaping) of the L-T relation. 
A. Del Popolo (Bergamo Univ., Italy)