Phase transitions and renormalization-group theory
The study of critical phenomena targets the qualitatively new phenomena that occur through the interactions of very large numbers of degrees of freedom. Such situations are typically realized near the onset of the transition between two thermodynamic phases. The special challenge of this field is thus due to the truly many-body nature of its subject. Another motivating challenge of the field has been the feasibility of immediate comparisons between the outcomes of sophisticated experiments and sophisticated theories, especially in condensed matter systems. Adding to this the wide variety of experimental and theoretical methods, it is seen that many cultures meet and exchange under the aegis of critical phenomena and phase transitions, contributing to the dynamism and intellectual enrichment of the field.