On two-loop effective action of 2d sigma model

In this paper, we study two-loop contribution to the effective action of a two-dimensional non-linear sigma model. We derive a new formula, which can be applicable to a regularization of general type. As examples, we obtain known results for the dimensional regularization and investigate new types of a cutoff one. Also, we discuss non-local contributions and restrictions on the regularization.

Automated summary

In this paper, the two-loop contribution to the effective action of a two-dimensional non-linear sigma model is studied. A new formula, applicable to a regularization of general type, is derived. Known results for dimensional regularization are obtained as examples, and new types of cutoff are investigated. Non-local contributions and restrictions on the regularization are also discussed.