Emerging AdS from Extremally Rotating NS5-branes

TL;DR

This paper explores the near-horizon geometry of extremally rotating NS5-branes, revealing emergent AdS structures, Virasoro symmetries, and matching entropies, with implications for understanding dualities in string theory.

Contribution

It demonstrates the emergence of AdS geometries and Virasoro symmetries in extremally rotating NS5-branes, providing a potential microscopic understanding via embedding in solvable string backgrounds.

Findings

Asymptotic symmetry group contains a chiral Virasoro algebra.

Entropy matches between boundary theory and bulk Bekenstein-Hawking entropy.

Geometry can be embedded in an exactly solvable string background.

Abstract

We investigate the near-horizon limit of extremally rotating NS5-branes. The resulting geometry has SL(2,R) \times U(1)^2 isometry. The asymptotic symmetry group contains a chiral Virasoro algebra, and we obtain two different realizations depending on the boundary conditions we impose. When one of the two angular momenta vanishes, the symmetry is enhanced to AdS_3. The entropy of the boundary theory can be estimated from the Cardy formula and it agrees with the Bekenstein-Hawking entropy of the bulk theory. We can embed the extremally rotating NS5-brane geometry in an exactly solvable string background, which may yield microscopic understanding of this duality, especially about the mysterious enhancement of the symmetry from AdS_2 to AdS_3. The construction suggests emerging Virasoro symmetries in the extreme corner of the (1+5) dimensional little string theory.