On the Quantum Bousso Bound in JT gravity

TL;DR

This paper proves the quantum Bousso bound in JT gravity across various vacua, deriving entropy formulas and establishing a stronger quantum null energy condition in a semiclassical setting.

Contribution

It provides a proof of the quantum Bousso bound in JT gravity for a broad class of vacua and introduces a new entropy formula applicable to models with reflecting boundaries.

Findings

Quantum Bousso bound proven in JT gravity for conformal vacua.

Derived a stronger quantum null energy condition.

Established entropy formula for models with reflecting boundaries.

Abstract

We prove the Strominger-Thompson quantum Bousso bound in the infinite class of conformal vacua in semiclassical JT gravity, with postive or negative cosmological constant. The Bousso-Fisher-Leichenauer-Wall quantum Bousso bound follows from an analogous derivation, requiring only initial quantum non-expansion. In this process, we show that the quantity ${2\pi k^{\mu}k^{\nu}<:T_{\mu\nu}:>-S''-\frac{6}{c}(S')^2}$ vanishes in any vacuum state, entailing a stronger version of Wall's quantum null energy condition. We derive an entropy formula in the presence of a generic class of two reflecting boundaries, in order to apply our argument to the half reduction model of de Sitter JT gravity.