English

Towering Gravitons in AdS$_3$/CFT$_2$

High Energy Physics - Theory 2026-04-23 v1

Abstract

BPS states in holographic CFTs are usually classified into supergravitons, namely BPS fluctuations around empty AdS, and black-hole microstates, which appear above an energy threshold. In AdS3_3/CFT2_2, however, this picture is incomplete because of additional degrees of freedom, called singletons, associated with boundary diffeomorphisms. We present a general procedure for extending the BPS spectrum of supergravitons by dressing them with singletons, thereby defining a generalized, gravity-sector Hilbert space that admits decomposition into affine multiplets of the full superconformal algebra. This extends the procedure previously proposed in arXiv:2505.14888 which was applicable only at low levels, by removing that limitation. We apply the new procedure to the D1-D5 CFT SymN(T4){\rm Sym}^N(T^4) and explicitly construct affine multiplets in the gravity sector for the N=2N=2 theory up to level h=2h=2. We find that, at the free orbifold point, the gravity-sector spectrum agrees with the CFT up to h=12h=\frac12. Upon turning on a deformation, however, states at h=1h=1 lift and the agreement improves to h=32h=\frac32. Interestingly, the lifting occurs between states in the gravity sector, involving mixtures of supergravitons and singletons, and stringy states. We conjecture that, upon deformation, the gravity-sector Hilbert space becomes the monotone Hilbert space while its complement becomes the fortuitous Hilbert space.

Keywords

Cite

@article{arxiv.2604.20663,
  title  = {Towering Gravitons in AdS$_3$/CFT$_2$},
  author = {Marcel R. R. Hughes and Kohei Jin and Daiki Matsumoto and Leon Miyahara and Masaki Shigemori},
  journal= {arXiv preprint arXiv:2604.20663},
  year   = {2026}
}

Comments

27 pages plus appendices

R2 v1 2026-07-01T12:30:38.373Z