A new AdS_4/CFT_3 Dual with Extended SUSY and a Spectral Flow

We construct a new AdS_4 background in Type IIB supergravity by means of a non-Abelian T-duality transformation on the Type IIA dual of ABJM. The analysis of probe and particle-like branes suggests a dual CFT in which each of the gauge groups is doubled. A common feature of non-Abelian T-duality is that in the absence of any global information coming from String Theory it gives rise to non-compact dual backgrounds, with coordinates living in the Lie algebra of the Lie group involved in the dualization. In backgrounds with CFT duals this poses obvious problems to the CFTs. In this paper we show that for the new AdS_4 background the gauge groups of the associated dual CFT undergo a spectral flow as the non-compact internal direction runs from 0 to infinity, which resembles Seiberg duality in N=1. This phenomenon, very reminiscent of the cascade, provides an interpretation in the CFT for the running of the non-compact coordinate, and suggests that at the end of the flow the extra charges disappear and the dual CFT is described by a 2-node quiver very similar to ABJM, albeit with reduced supersymmetry.Comment: 40 pages, published versio

Minimal flux Minkowski classification

We classify Minkowski$_4$ solutions in type IIA supergravity, with N=2 supersymmetry and an SU(2) R-symmetry of a certain type. Many subcases can be reduced to relatively simple PDEs, among which we recover various intersecting brane systems, and AdS$_d$ solutions, $d=5,6,7$, and in particular the recently found general massive AdS$_7$ solutions. Imposing compactness of the internal six-manifold we obtain promising solutions with localized D-branes and O-planes.Comment: v2: Result slightly strengthened, typos corrected. v3: Published Versio

AdS6AdS_6 T-duals and Type IIB AdS6×S2AdS_6\times S^2 Geometries with 7-Branes

We show that the first $AdS_6$ backgrounds in Type IIB supergravity known in the literature, namely those constructed via T-duality from the Brandhuber-Oz solution to massive IIA, fit within an extension of the global $AdS_6 \times S^2$ solutions with 7-branes warped over a Riemann surface $\Sigma$, recently classified by D'Hoker, Gutperle and Uhlemann, that describes delocalised 5-branes and 7-branes. The solution constructed through Abelian T-duality provides an explicit example of a Riemann surface with the topology of an annulus, that includes D7/O7-branes. In turn, the solution generated through non-Abelian T-duality arises from the upper half-plane.Comment: 36 pages plus appendices. 3 figures. v2: reference added. v3: section 5 improved, version accepted in JHE

A N=2\mathcal{N}=2 Supersymmetric AdS4AdS_4 Solution in M-theory with Purely Magnetic Flux

We find a new $\mathcal{N}=2$ $AdS_4$ solution in M-theory supported by purely magnetic flux via a sequence of abelian and non-abelian T-dualities. This provides the second known example in this class besides the uplift of the Pernici and Sezgin solution to 7d gauged supergravity constructed in the eighties. We compute the free energy of the solution, and show that it scales as $N^{3/2}$. It is intriguing that even though the natural holographic interpretation is in terms of M5-branes wrapped on a special Lagrangian 3-cycle, this solution does not exhibit the expected $N^3$ behavior.Comment: 19 pages plus appendices. v2 metadata amended, reference adde

AdS3_3 vacua realising osp(n∣2)\mathfrak{osp}(n|2) superconformal symmetry

We consider ${\cal N}=(n,0)$ supersymmetric AdS$_3$ vacua of type II supergravity realising the superconformal algebra $\mathfrak{osp}(n|2)$ for $n>4$. For the cases $n=6$ and $n=5$, one can realise these algebras on backgrounds that decompose as folations of AdS$_3\times \mathbb{CP}^3$ ( squashed $\mathbb{CP}^3$ for $n=5$) over an interval. We classify such solutions with bi-spinor techniques and find the local form of each of them: They only exist in (massive) IIA and are defined locally in terms of an order 3rd order polynomial $h$ similar to the AdS$_7$ vacua of (massive) IIA. Many distinct local solutions exist for different tunings of $h$ that give rise to bounded or (or semi infinite) intervals bounded by physical behaviour. We show that it is possible to glue these local solutions together by placing D8 branes on the interior of the interval without breaking supersymmetry, which expands the possibilities for global solutions immensely. We illustrate this point with some simple examples. Finally we also show that AdS$_3$ vacua for $n=7,8$ only exist in $d=11$ supergravity and are all locally AdS$_4\times$S$^7$.Comment: 29 pages + appendice