Comments on Lumps from RG flows

TL;DR

This paper examines a proposed string field theory solution for RG flow endpoints, revealing an anomaly in the equations of motion but confirming correct energy shifts through gauge invariant action.

Contribution

It identifies an anomaly in the proposed solutions for RG flows in string field theory while confirming their energy predictions.

Findings

Solution class has an anomaly in equations of motion

Gauge invariant action reproduces expected energy shifts

Analysis clarifies limitations of current RG flow solutions

Abstract

In this note we investigate the proposal of Ellwood and one of the authors et al. to construct a string field theory solution describing the endpoint of an RG flow from a reference BCFT to a target BCFT*. We show that the proposed class of solutions suffers from an anomaly in the equations of motion. Nevertheless, the gauge invariant action exactly reproduces the expected shift in energy.