AdS_3 x S^3 x S^3 x S^1 Solutions of Type IIB String Theory
Aristomenis Donos, Jerome P. Gauntlett, James Sparks
TL;DR
The paper constructs globally well-defined AdS$_3$ backgrounds in Type IIB supergravity whose internal space is $S^3 imes S^3 imes S^1$, starting from local AdS$_3$ solutions with NS flux and dilaton. A step-by-step topological assembly—$B_4 o S^2 imes S^2$, then $M_5 o S^3 imes S^2$, then $M_6 o S^3 imes S^3$—is augmented by a quotient to enable integral three-form flux; flux quanta $(M_1,M_2)$ are tied to coprime integers $(p,q)$ via $M_1=M(p+q)^2$ and $M_2=Mq^2$, and the central charge is $c=6n_1rac{(M_1-M_2)M_2}{M_1}$, independent of the deformation parameter $Q$. The authors show that $Q eq0$ deformations yield a continuous family with the same $c$, interpreted as exactly marginal in the dual $(0,2)$ SCFT, while limits as $Q o0$ reveal subtleties in global identifications. They further extend the construction to more general identifications, maintaining the same central-charge structure but with more flexible flux data. Overall, the work provides a concrete global realization of a rich AdS$_3$ class in IIB, clarifying flux quantisation, topology, and holographic data for a family of $(0,2)$ SCFTs. Key results include the explicit global topology $S^3 imes S^3 imes S^1$, the flux-quantisation prescription via the $Z_{(p+q)q}$ quotient, and the central charge formula that connects geometric data to CFT characteristics. This advances the understanding of AdS$_3$/CFT$_2$ in string theory by producing new globally well-defined backgrounds with nontrivial fluxes and outlining a pathway to their holographic interpretation.
Abstract
We analyse a recently constructed class of local solutions of type IIB supergravity that consist of a warped product of AdS_3 with a seven-dimensional internal space. In one duality frame the only other non-vanishing fields are the NS three-form and the dilaton. We analyse in detail how these local solutions can be extended to globally well-defined solutions of type IIB string theory, with the internal space having topology S^3 x S^3 x S^1 and with properly quantised three-form flux.
