Estimating Quantum Gravity Corrections to Correlators near Black Holes

TL;DR

This paper estimates quantum gravity effects near black holes in AdS spacetime, showing that corrections to correlators are exponentially suppressed and constraining certain models predicting large deviations.

Contribution

It introduces a method to estimate quantum gravity corrections to correlators near black holes and demonstrates their exponential suppression in typical pure states.

Findings

Corrections to correlators are of order exp(-S/2).

Correlator behavior differs from thermal state estimates.

Results constrain models predicting large quantum gravity effects.

Abstract

We analyze the size of quantum gravity effects near black hole horizons. By considering black holes in asymptotically AdS spacetime, we can make use of the "quantum deviation" to estimate the size of quantum gravity corrections to the semiclassical analysis. We find that, in a typical pure state, corrections to correlation functions are typically of order exp(-S/2). Both the magnitude and time dependence of the correlator differ from previous results related to the spectral form factor, which estimated the correlator in a thermal state. Our results severely constrain proposals, such as non-violent unitarization and some versions of fuzzballs, that predict significant corrections to the semiclassical computation of correlation functions near black holes. We point out one possible loophole: our results rely on the standard result that bulk reconstruction is state independent for small perturbations outside the black hole.