nLab
effective action functional

Context

Variational calculus

Physics

physics, mathematical physics, philosophy of physics

Surveys, textbooks and lecture notes


theory (physics), model (physics)

experiment, measurement, computable physics

Contents

Idea

In the context of quantum field theory an effective action is an object obtained from a more fundamental action functional by “averaging out” the dependency on certain variables.

There are two different notions of effective action

  1. The one-particle irreducible action (“1PI action”);

  2. The Wilsonian effective action of effective quantum field theory.

1PI action

(…)

Wilsonian effective action

(…)

References

A discussion (with an eye towards supersymmetric quantum field theory and Seiberg duality) is in section 2.1 of

  • Flip Tanedo, Notes on Seibergology (pdf)

A review of effective actions in the background field formalism is in section 3.1 of

  • Darren Trevor Grasso, Higher order contributions to the effective action of 𝒩=2\mathcal{N} = 2 and 44 supersymmetric Yang-Mills theories from heat kernel techniques in superspace Thesis (2007) (web)

Revised on October 24, 2011 14:02:15 by Urs Schreiber (89.204.153.107)