AdS3 Black Holes and a Stringy Exclusion Principle

TL;DR

This paper explores the duality between AdS3 black hole microstates and conformal field theory states, revealing a stringy exclusion principle that limits BPS particle numbers, with implications for black hole entropy and spectrum matching.

Contribution

It demonstrates a stringy exclusion principle in AdS3/CFT2 correspondence, linking BPS state bounds to chiral primary charges, beyond perturbative analysis.

Findings

Spectrum of chiral primaries matches multi-particle BPS states for particle numbers below a bound.

An upper limit on BPS particle number is derived from the U(1) charge of chiral primaries.

The black hole entropy and temperature are consistent with the density matrix from orbifolding.

Abstract

The duality relating near-horizon microstates of black holes obtained as orbifolds of a subset of AdS3 to the states of a conformal field theory is analyzed in detail. The SL(2,R) invariant vacuum on AdS3 corresponds to the NS-NS vacuum of the conformal field theory. The effect of the orbifolding is to produce a density matrix, the temperature and entropy of which coincide with the black hole. For string theory examples the spectrum of chiral primaries agrees with the spectrum of multi-particle BPS states for particle numbers less than of order the central charge. An upper bound on the BPS particle number follows from the upper bound on the U(1) charge of chiral primaries. This is a stringy exclusion principle which cannot be seen in perturbation theory about AdS3.