QNEC-Preserving IR Regulators for the Entropy

Abstract

Recent work by Ishibashi, Maeda, and Mefford shows that the validity of the QNEC is sensitive to the IR regulator that one uses to define the entropy and its variations. In this note we discuss two general options that preserve both the QNEC and a physically-sensible notion of entropy density. We illustrate the application of each through an example. An important guiding principle is that an IR regulator should have a physical interpretation.