A Fermi Surface Model for Large Supersymmetric AdS_5 Black Holes

TL;DR

This work addresses the microscopic description of large 1/16-BPS AdS$_5$ black holes in AdS/CFT by constructing a fermionic shell model within $\mathcal N=4$ SYM. The authors develop a Fermi surface picture using fermionic shells $A^{(I)1}$, supplemented by bosonic excitations, to build primaries that saturate the BPS bound and reproduce the qualitative scalings of angular momentum and entropy with R-charges in two regimes: $|J|\gg \mathcal Q$ and $|J|\sim \bar J$, corresponding to $J/N^2 \sim (\mathcal Q/N^2)^{3/2}$ and $J/N^2 \sim (\mathcal Q/N^2)^2$, respectively. They analyze both closed-shell ($\bar J=0$) and open-shell ($\bar J=J$) constructions, compute charges, and show that bosonic insertions yield macroscopic entropy $S$ scaling with the charge, $S\sim \mathcal Q$, up to order-one coefficients. Generalizations to multiple fermionic bands and generalized shells reveal bounds on the angular-momentum coefficients, consistently staying below the gravity values, and suggesting a rich landscape of potential dual black objects in AdS$_5\times S^5$. The results provide a concrete microscopic CFT framework for understanding large 1/16-BPS black holes and motivate further exploration of primaries and additional field content.

Abstract

We identify a large family of 1/16 BPS operators in N=4 SYM that qualitatively reproduce the relations between charge, angular momentum and entropy in regular supersymmetric AdS_5 black holes when the main contribution to their masses is given by their angular momentum.