QNEC-Preserving IR Regulators for the Entropy

TL;DR

This paper explores IR regulators that preserve the Quantum Null Energy Condition (QNEC) and a sensible notion of entropy density, emphasizing physical interpretability and illustrating their application with examples.

Contribution

It introduces two IR regulator options that maintain QNEC validity and entropy density, providing a framework for physically meaningful entropy regulation.

Findings

Both regulators preserve QNEC in examples.

Regulators have clear physical interpretations.

Framework guides future entropy regulation approaches.

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.