BMS Field Theories and Weyl Anomaly

TL;DR

This paper investigates Weyl anomalies in 2D BMS-invariant field theories, revealing a Carrollian Liouville action and advancing understanding of their conformal properties on null surfaces.

Contribution

It introduces a new analysis of Weyl anomalies in BMS field theories, deriving a novel Carrollian Liouville action distinct from previous models.

Findings

Derived an expression for Weyl anomaly in BMS field theories.

Identified a new Carrollian Liouville action.

Enhanced understanding of conformal structures on null surfaces.

Abstract

Two dimensional field theories with Bondi-Metzner-Sachs symmetry have been proposed as duals to asymptotically flat spacetimes in three dimensions. These field theories are naturally defined on null surfaces and hence are conformal cousins of Carrollian theories, where the speed of light goes to zero. In this paper, we initiate an investigation of anomalies in these field theories. Specifically, we focus on the BMS equivalent of Weyl invariance and its breakdown in these field theories and derive an expression for Weyl anomaly. Considering the transformation of partition functions under this symmetry, we derive a Carrollian Liouville action different from ones obtained in the literature earlier.