Holographic Description of M-branes via AdS$_2$

TL;DR

This paper explores specific AdS2 solutions in type IIB string theory from brane intersections, proposing they serve as gravity duals to M(atrix) models related to M5 and M2 branes, revealing insights into their IR and UV behaviors.

Contribution

It introduces new AdS2 geometries from brane intersections as potential duals to M(atrix) models, connecting lower-dimensional AdS spaces to higher-dimensional M-theory branes.

Findings

Reveals N^3 scaling in holographic free energy with a cutoff.

Identifies geometries as duals to IR phases of (2,0) M5 branes.

Provides examples of deconstructed extra dimensions with well-defined UV limits.

Abstract

We study $\textrm{AdS}_2\times S^4 \times S^2 \times \Sigma_2$ solutions in type IIB string theory arising from D1 -- D3 -- NS5 brane intersections. These backgrounds enjoy sixteen supercharges and the corresponding internal geometry is non-compact due to the specific form of the warping w.r.t. the Riemann surface $\Sigma_2$. Even though a direct computation of the holographic free energy of the would-be dual CFT$_1$ yields a divergent behaviour, it reveals the typical $N^3$ scaling of a 6d theory upon introducing a hard cut-off. We claim that such geometries may be interpreted as the gravity duals of M(atrix) models describing an IR phase of the $(2,0)$ theory of M5 branes, in presence of momentum and NUT charges. We discuss parallel $\textrm{AdS}_2$ geometries describing longitudinal M2 branes in the UV, where the counting of the number of degrees of freedom correctly reproduces the expected $N^{3/2}$ behaviour of the dual field theory. These geometries provide explicit examples where deconstructed extra dimensions yield well-defined UV descriptions in terms of higher-dimensional CFTs.