Outline

• The role of interaction’s range
• The role of dimensionality
• Classification of phase transitions
• Broken symmetry
• Order parameter
• Ginzburg-Landau Theory
• Ginzburg criterion

Scope

• To point out the role of spatial dimensions and the range of interactions in a phase transition;
• To investigate the characteristics of different kinds of phase transitions and the consequences of a symmetry braking phase transitions;
• To recognize that if the correlation length of microscopic degrees of freedom diverges at the critical point (short range interaction) there should exist a macroscopic “hydrodynamic” theory for phase transitions and their order parameters