Effective actions, relative cohomology and Chern Simons forms

TL;DR

This paper derives explicit expressions for WZW effective actions for a simple group G broken to a subgroup H, highlighting their similarity to Chern-Simons forms and discussing applications.

Contribution

It provides a straightforward method to obtain all WZW effective actions for G to H symmetry breaking, clarifying their relation to Chern-Simons forms.

Findings

Explicit expressions for WZW actions are derived.

The formal similarity to Chern-Simons forms is explained.

Applications of these results are discussed.

Abstract

The explicit expression of all the WZW effective actions for a simple group G broken down to a subgroup H is established in a simple and direct way, and the formal similarity of these actions to the Chern-Simons forms is explained. Applications are also discussed.