For a QFT to be scale-invariant, its coupling parameters must be independent of the energy-scale, and this is indicated by the vanishing of the beta-functions of the theory. Such theories are also known as [[Renormalization group|fixed points]] of the corresponding renormalization group flow.<ref>[[Jean Zinn-Justin|J. Zinn-Justin]] (2010) Scholarpedia article [http://www.scholarpedia.org/article/Critical_Phenomena:_field_theoretical_approach "Critical Phenomena: field theoretical approach"].</ref> | For a QFT to be scale-invariant, its coupling parameters must be independent of the energy-scale, and this is indicated by the vanishing of the beta-functions of the theory. Such theories are also known as [[Renormalization group|fixed points]] of the corresponding renormalization group flow.<ref>[[Jean Zinn-Justin|J. Zinn-Justin]] (2010) Scholarpedia article [http://www.scholarpedia.org/article/Critical_Phenomena:_field_theoretical_approach "Critical Phenomena: field theoretical approach"].</ref> |