Symmetry breaking, central charges and the AdS2/CFT1 correspondence

When two-dimensional Anti-de Sitter space (AdS2) is endowed with a non-constant dilaton the origin of the central charge in the Virasoro algebra generating the asymptotic symmetries of AdS2 can be traced back to the breaking of the SL(2,R) isometry group of AdS2. We use this fact to clarify some controversial results appeared in the literature about the value of the central charge in these models.