Editing Critical phenomena (section)

==Critical exponents and universality==

As we approach the critical point, these diverging observables behave as <math>A(T)\propto (T-T_c)^\alpha</math> for some exponent <math>\alpha\,,</math> where, typically, the value of the exponent α is the same above and below T<sub>c</sub>. These exponents are called [[critical exponents]] and are robust observables. Even more, they take the same values for very different physical systems. This intriguing phenomenon, called [[universality (dynamical systems)|universality]], is explained, qualitatively and also quantitatively, by the [[renormalization group]].<ref>{{Cite journal|last=Fisher|first=Michael E.|date=1998-04-01|title=Renormalization group theory: Its basis and formulation in statistical physics|journal=Reviews of Modern Physics|volume=70|issue=2|pages=653–681|doi=10.1103/RevModPhys.70.653|bibcode=1998RvMP...70..653F}}</ref>