How to compute the thermodynamics of a glass using a cloned liquid

The recently proposed strategy for studying the equilibrium thermodynamics of the glass phase using a molecular liquid is reviewed and tested in detai ls on the solvable case of the p-spin model. We derive the general phase di agram, and confirm the validity of this procedure. We point out the efficac y of a system of two weakly coupled copies in order to identify the glass t ransition, and the necessity to study a system with m < 1 copies ('clones') of the original problem in order to derive the thermodynamic properties of the glass phase. (C) 1999 Published by Elsevier Science B.V. All rights re served.