Consequences of the gauging of Weyl symmetry and the two-dimensional conformal anomaly

TL;DR

This paper explores how gauging Weyl symmetry affects the conformal anomaly in two-dimensional models, revealing differences in RG flow between scale and conformal invariant theories and introducing a new anomaly charge.

Contribution

It generalizes the local renormalization group approach to gauged Weyl symmetry, providing nonperturbative constraints on anomalies and beta functions in 2D models with boundaries.

Findings

RG flow between scale invariant theories differs from conformal ones due to a new anomaly charge.

Standard schemes cannot nullify the new charge unless the theory is conformal in flat space.

Illustrative examples show limitations of naive local treatments in scale and conformal models.

Abstract

We discuss the generalization of the local renormalization group approach to theories in which Weyl symmetry is gauged. These theories naturally correspond to scale invariant - rather than conformal invariant - models in the flat space limit. We argue that this generalization can be of use when discussing the issue of scale vs conformal invariance in quantum and statistical field theories. The application of Wess-Zumino consistency conditions constrains the form of the Weyl anomaly and the beta functions in a nonperturbative way. In this work we concentrate on two dimensional models including also the contributions of the boundary. Our findings suggest that the renormalization group flow between scale invariant theories differs from the one between conformal theories because of the presence of a new charge that appears in the anomaly. It does not seem to be possible to find a general scheme for which the new charge is zero, unless the theory is conformal in flat space. Two illustrative examples involving flat space's conformal and scale invariant models that do not allow for a naive application of the standard local treatment are given.