Type IIB supergravity on squashed Sasaki-Einstein manifolds
Davide Cassani, Gianguido Dall'Agata, Anton F. Faedo
TL;DR
This work constructs a consistent ${ m N}=4$ Kaluza–Klein truncation of type IIB supergravity on general squashed Sasaki–Einstein 5-manifolds, retaining the universal gauge-sector modes and a set of massive KK states. The resulting five-dimensional theory includes a gravity multiplet, two vector multiplets, and a tensor hierarchy whose couplings are fixed by an embedding tensor, yielding a gauge group $G={ m Heis}_3 imes{ m U}(1)_R$ and a scalar potential with two AdS vacua (one supersymmetric, one non-supersymmetric). The truncation is explicitly matched to ${ m N}=4$ gauged supergravity, with a detailed derivation of the ungauged and gauged sectors, covariant field strengths, and the role of RR flux $k$ in obstructing or enabling dualizations. The paper also analyzes the vacua and their spectra, discusses holographic RG flows between the AdS points, and outlines a web of possible further reductions to 4D and other ${ m N}=2$ or ${ m N}=4$ theories, thereby expanding the set of exact embeddings of 5D models into type IIB supergravity for AdS/CFT applications.
Abstract
We provide a consistent N=4 Kaluza-Klein truncation of type IIB supergravity on general 5-dimensional squashed Sasaki-Einstein manifolds. Our reduction ansatz keeps all and only the supergravity modes dual to the universal gauge sector of the associated conformal theories, via the gauge/gravity correspondence. The reduced 5-dimensional model displays remarkable features: it includes both zero-modes as well as massive iterations of the Kaluza-Klein operators on the internal manifold; it contains tensor fields dual to vectors charged under a non-abelian gauge group; it has a scalar potential with a non-supersymmetric AdS vacuum in addition to the supersymmetric one.
