A note on scaling arguments in the effective average action formalism

Understand

The effective average action (EAA) is a scale dependent effective action where a scale $k$ is introduced via an infrared regulator.

• The $k-$dependence of the EAA is governed by an exact flow equation to which one associates a boundary condition at a scale $\mu$.
• We show that the $\mu-$dependence of the EAA is controlled by an equation fully analogous to the Callan-Symanzik equation which allows to define scaling quantities straightforwardly.
• Particular attention is paid to composite operators which are introduced along with new sources.