String Theory and Black Hole Complementarity

TL;DR

Polchinski analyzes whether string theory can address the black hole information problem by examining the Nice Slice construction and black hole complementarity. He argues that evolving initial data on smooth spacelike slices in a Schwarzschild geometry yields Hawking radiation that is thermal and highly entangled with interior modes, consistent with EFT up to late times. The framework of black hole complementarity posits that interior and exterior degrees of freedom are the same underlying variables viewed in different Lorentz frames, a possibility that gains potential support from stringy effects such as transverse growth $\sqrt{\ln \gamma}$ and longitudinal spreading, which may induce nonlocal correlations along the nice slice. A light-cone string-field calculation of field commutators suggests nonlocal behavior at large boosts, with a growth scale $\sim e^{\omega(\alpha(t)-1)}$ where $\omega = t/4GM$ and $\alpha(t)=2+\alpha' t/4$, yet on-shell amplitudes remain largely local; the issue remains unsettled and requires further work. Overall the paper frames a plausible string-theory resolution of information loss via complementarity, but conclusive evidence and a gauge-invariant formulation are still lacking.

Abstract

Is string theory relevant to the black hole information problem? This is an attempt to clarify some of the issues involved. Presented at Strings '95.

Figures (2)

• Figure 1: Nice slicing of the Kruskal $x^+ x^-$ plane. The slice which is asymptotic to the $t=0$ surface is drawn as a solid line, with earlier and later slices shown dashed.
• Figure 2: a) Fermi-scale wavepackets just inside and just outside the horizon. b) Subsequent state of several pairs of packets along a nice slice.