Inverse Freezing in Mean-Field Models of Fragile Glasses

A disordered spin model suitable for studying inverse freezing in fragile glass-forming systems is introduced. The model is a microscopic realization of the ``random-first order'' scenario in which the glass transition can be either continuous or discontinuous in thermodynamic sense. The phase diagram exhibits a first-order transition line between two fluid phases terminating at a critical point. When the interacting degrees of freedom are entropically favoured an inverse static glass transition and a double inverse dynamic freezing appear.