Massive IIA Supergravity Research Articles

Searching for Coleman–de Luccia bubbles in AdS compactifications

Coleman-de Luccia transitions are spontaneous processes of nucleation of bubbles within metastable gravitational vacua including in their interior a true stable vacuum. From the perspective of lower-dimensional gauged supergravities obtained by truncating Type II and M-theory, these instantonic processes are represented by smooth domain walls featured by de Sitter foliations. These geometries must connect two different AdS vacua in such a way that the wall is defined by an interior and an exterior. We propose a first-order formulation for such radial flows and present two fully backreacted examples of gravitational instantons obtained through this technique, beyond the thin-wall approximation. In the first we consider minimal 7d supergravity describing the truncation of M-theory over a squashed 4-sphere and admitting two AdS$_7$ vacua, one supersymmetric and the other not. Secondly we apply the same strategy to 6d Romans supergravity obtained with consistent truncation of massive IIA supergravity. Also in this case we derive a dS domain wall interpolating between the Brandhuber-Oz vacuum and the non-supersymmetric AdS$_6$ vacuum of the theory.

New AdS3/CFT2 pairs in massive IIA with (0, 4) and (4, 4) supersymmetries

We construct a new class of AdS3 × S3 × M4 solutions of massive Type IIA supergravity with (0, 4) supersymmetries and SU(3) structure. We study in detail two subclasses of these solutions. The first subclass is when M4 = S2× Σ2, with Σ2 a 2d Riemann surface, and the geometry is foliated over the Σ2. We interpret these solutions as duals to surface defect CFTs within the 6d (1, 0) CFTs dual to the AdS7 × S2 × I solutions of massive IIA supergravity. The second subclass is when M4 = \U0001d54b3 × I and the geometry is foliated over the interval. In this case supersymmetry is enhanced to (4, 4) in the massless limit, and the solutions are the sought-for holographic duals of (4, 4) CFTs living in two dimensional D2-NS5-D4 Hanany-Witten brane set-ups. In turn, in the massive case the solutions find an interpretation as D2-D4 branes embedded in Type I’ string theory. We construct explicit quiver gauge theories from the different brane set-ups that flow in the IR to the 2d dual CFTs dual to the solutions. We check the validity of our proposals with the matching between the field theory and holographic central charges.

Comments on classical AdS flux vacua with scale separation

AdS flux vacua with a parametric separation between the AdS and KK scales have been conjectured to be in the Swampland. We study flux compactifications of massive IIA supergravity with O6 planes which are claimed to allow moduli-stabilised and scale separated AdS3 and AdS4 vacua at arbitrary weak coupling and large volume. A recent refinement of the AdS Distance Conjecture is shown to be inconsistent with this class of AdS3 vacua because the requisite discrete higher form symmetries are absent. We further perform a tree-level study of non-perturbative decays for the nonsupersymmetric versions of the AdS3 solutions, and find that the vacua are stable within this approximation. Finally, we provide an initial investigation of the would-be dual CFT2s and CFT3s. We study roughly a dozen different models and find for all AdS4 DGKT-type vacua that the dual operators to the lightest scalars have integer dimensions. For the putative CFT2 dual theories of the AdS3 vacua we find no integer dimensions for the operators.

Positive Energy and Non-SUSY Flows in ISO(7) Gauged Supergravity

We consider maximal gauged supergravity in 4D with the ISO(7) gauge group, which arises from a consistent truncation of massive IIA supergravity on a six-sphere. Within its G2-invariant sector, the theory is known to possess a supersymmetric AdS extremum, as well as two non-supersymmetric ones. In this context, we provide a first-order formulation of the theory by making use of the Hamilton–Jacobi (HJ) formalism. This allows us to derive a positive energy theorem for both non-supersymmetric extrema. Subsequently, we also find novel non-supersymmetric domain walls (DWs) interpolating between the supersymmetric extremum and each of the other two. Finally, we discuss a perturbative HJ technique that may be used in order to solve for curved DW geometries.

Bubble instabilities of mIIA on AdS$_4\times S^6$

We consider compactifications of massive IIA supergravity on a six-sphere. This setup is known to give rise to non-supersymmetric AdS_44 vacua preserving \mathrm{SO}(7)SO(7) as well as G_22 residual symmetry. Both solutions have a round S^6S6 metric and are supported by the Romans’ mass and internal F_{6}F6 flux. While the \mathrm{SO}(7)SO(7) invariant vacuum is known to be perturbatively unstable, the G_22 invariant one has been found to have a fully stable Kaluza-Klein spectrum. Moreover, it has been shown to be protected against brane-jet instabilities. Motivated by these results, we study possible bubbling solutions connected to the G_22 vacuum, representing non-perturbative instabilities of the latter. We indeed find an instability channel represented by the nucleation of a bubble of nothing dressed up with a homogeneous D2 brane charge distribution in the internal space. Our solution generalizes to the case where S^6S6 is replaced by any six-dimensional nearly-K"ahler manifold.

Supersymmetric spectroscopy on AdS4× S7 and AdS4× S6

New techniques based on Exceptional Field Theory have recently allowed for the calculation of the Kaluza-Klein spectra of certain AdS4 solutions of D = 11 and massive IIA supergravity. These are the solutions that consistently uplift on S7 and S6 from vacua of maximal four-dimensional supergravity with SO(8) and ISO(7) gaugings. In this paper, we provide an algorithmic procedure to compute the complete Kaluza-Klein spectrum of five such AdS4 solutions, all of them N\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\mathcal{N} $$\\end{document} = 1, and give the first few Kaluza-Klein levels. These solutions preserve SO(3) and U(1) × U(1) internal symmetry in D = 11, and U(1) (two of them) and no continuous symmetry in type IIA. Together with previously discussed cases, our results exhaust the Kaluza-Klein spectra of known supersymmetric AdS4 solutions in D = 11 and type IIA in the relevant class.

Marginal deformations of a class of AdS3 mathcal{N} = (0, 4) holographic backgrounds

We discuss marginal deformations of warped AdS3×S2 solutions preserving small mathcal{N} = (0, 4) supersymmetry in massive IIA and eleven-dimensional supergravity and obtain a whole family of new solutions. We characterise these new backgrounds by studying some observables like the quantised charges, associated Hannany-Witten brane set-ups and the holographic central charge, the latter is shown to be invariant under the deformation. The study of the preservation of supersymmetry shows that the new backgrounds support a dynamical SU(2) structure on the internal five-dimensional space.

Holography for 2D N=(0,4) quantum field theory

We study the correspondence between ${\mathrm{AdS}}_{3}$ massive IIA supergravity vacua and two-dimensional $\mathcal{N}=(0,4)$ quiver quantum field theories. After categorizing all kinds of gravity solutions, we demystify the ones that seem to reflect anomalous gauge theories. In particular, we prove that there are bound states of D-branes on the boundary of the space that provide the dual quiver theory with exactly the correct amount of flavor symmetry in order to cancel its gauge anomalies. Then we propose that the structure of the field theory should be complemented with additional bifundamental matter, which we argue may only be $\mathcal{N}=(4,4)$ hypermultiplets. Finally, we construct a Bogomol'nyi-Prasad-Sommerfield (BPS) string configuration and use the old and new supersymmetric matter to build its dual ultraviolet operator. During this holographic synthesis, we uncover some interesting features of the quiver superpotential and associate the proposed operator with the same classical mass of its dual BPS string.

Stable Nonsupersymmetric Anti-de Sitter Vacua of Massive IIA Supergravity.

Stable nonsupersymmetric anti-de Sitter (AdS) vacua of string theory are widely believed not to exist. In this Letter, we analytically compute the full bosonic Kaluza-Klein spectrum around the G_{2}-invariant nonsupersymmetric AdS_{4} solution of massive IIA supergravity and show that it is perturbatively stable. We also provide evidence that six other nonsupersymmetric AdS_{4} solutions of massive IIA supergravity are perturbatively stable. Since previous studies have indicated that these AdS vacua may also be nonperturbatively stable, our findings pose a challenge to the swampland conjecture.

Classical de Sitter solutions in three dimensions without tachyons?

We continue the study of compactifications of massive IIA supergravity on G2 orientifolds and demonstrate that breaking supersymmetry with anti-D2 and anti-D6 sources leads to 3d theories for which the typical tachyons haunting classical dS solutions can be absent. However for a concrete torus example the meta-stable dS window disappears after a quantization of fluxes and charges. We discuss the prospects of more general G2 compactifications and argue that they could potentially alleviate the tachyon problem by introducing larger tadpole numbers and warped throats. However, exactly those ingredients then seem to push the vacuum towards the brink of perturbative brane–flux decay in the open string sector. This is either a remarkable illustration of the no-dS swampland conjecture or such vacua live in very difficult to control regions of parameter space.

Smearing orientifolds in flux compactifications can be OK

We present explicit examples of supergravity solutions corresponding to backreacting localised (non-intersecting) O6 planes in flux reductions of massive IIA supergravity and address some criticism towards the very existence of such solutions. We verify in detail how the smeared orientifold solution becomes a good approximation to the localised solution in the large volume/weak coupling limit, as expected. We also find an exotic solution where prior to backreaction the internal space has a boundary and when backreaction is included the boundary disappears and the space closes off. The exotic example is however outside of the supergravity approximation everywhere.

Dirac branes for Dirichlet branes: Supergravity actions

Nontrivial Bianchi identities with local magnetic sources are solved by recognizing that gauge potentials are sections rather than globally defined functions, but properly accounting for the source degrees of freedom requires a modification of the field strength. Following work by Teitelboim and by Cariglia and Lechner, we extend Dirac's string formalism for monopoles to D-branes in type IIA and IIB string theory. We give novel derivations of brane-induced Chern-Simons terms in the supergravity actions, including a prescription for integrating over potentials in the presence of magnetic sources. We give a noncovariant formulation of the IIB theory, keeping only the independent degrees of freedom of the self-dual 4-form potential. Finally, it is well-known that D8-branes source the mass parameter of IIA supergravity; we show that the additional couplings of the massive IIA supergravity, including on other D-brane worldvolumes, are a consequence of the corresponding Dirac branes.

Consistent truncations of supergravity and 1/2-BPS RG flows in 4d SCFTs

With the purpose of holographically describing flows from a large family of four dimensional mathcal{N} = 1 and mathcal{N} = 2 conformal field theories, we discuss truncations of seven dimensional supergravity to five dimensions. We write explicitly the reduced gauged supergravity and find BPS equations for simple configurations. Lifting these flows to eleven dimensions or Massive IIA supergravity, we present string duals to RG flows from strongly coupled conformal theories when deformed by marginal and/or relevant operators. We further discuss observables common to infinite families of mathcal{N} = 1 and mathcal{N} = 2 QFTs in this context.

Flowing to mathcal{N} = 3 Chern-Simons-matter theory

New renormalisation group flows of three-dimensional Chern-Simons theories with a single gauge group SU(N ) and adjoint matter are found holographically. These RG flows have an infrared fixed point given by a CFT with mathcal{N} = 3 supersymmetry and SU(2) flavour symmetry. The ultraviolet fixed point is again described by a CFT with either mathcal{N} = 2 and SU(3) symmetry or mathcal{N} = 1 and G2 symmetry. The gauge/gravity duals of these RG flows are constructed as domain-wall solutions of a gauged supergravity model in four dimensions that enjoys an embedding into massive IIA supergravity. A concrete RG flow that brings a mass deformation of the mathcal{N} = 2 CFT into the mathcal{N} = 3 CFT at low energies is described in detail.

AdS3 solutions with from S3 × S3 fibrations

AbstractWe study warped AdS3 solutions in massive IIA supergravity preserving and supersymmetry. We consider solutions whose internal spaces decompose as an S3 × S3 fibration and a interval over which the rest of the solution is foliated. We present necessary and sufficient conditions for these solutions to exist, in terms of systems of ordinary differential equations and find several new analytic and numerical examples with internal spaces bounded between D‐brane and O‐plane behaviors.

Non-integrability on AdS3 supergravity backgrounds

We investigate classical integrability on two recently discovered classes of back- grounds in massive IIA supergravity. These vacua are of the form AdS3 × S2 × ℝ × CY2, they preserve small mathcal{N} = (0, 4) supersymmetry and are associated with D8−D6−D4−D2 Hanany-Witten brane set-ups. We choose an appropriate string embedding and use differential Galois theory on its associated Hamiltonian system, intending to produce the conditions under which Liouvillian solutions may occur. By constraining the parameters of the system according to the consistency of the associate brane set-ups we prove that no such conditions exist, yielding the complete non-integrability of these vacua. That is, up to the trivial cases where the background reduces to the Abelian and non-Abelian T-dual of AdS3 × S3 × T4.

AdS3 solutions in massive IIA, defect CFTs and T-duality

We establish a map between AdS3×S2 and AdS7 solutions to massive IIA supergravity that allows one to interpret the former as holographic duals to D2-D4 defects inside 6d (1,0) CFTs. This relation singles out in a particular manner the AdS3×S2 solution constructed from AdS3×S3×CY2 through non-Abelian T-duality, with respect to a freely acting SU(2). We find explicit global completions to this solution and provide well-defined (0,4) 2d dual CFTs associated to them. These completions consist of linear quivers with colour groups coming from D2 and D6 branes and flavour groups coming from D8 and D4 branes. Finally, we discuss the relation with flows interpolating between AdS3×S2×T4 geometries and AdS7 solutions found in the literature.

Supersymmetric AdS7 and AdS6 vacua and their consistent truncations with vector multiplets

Using exceptional field theory we construct supersymmetric warped AdS7 vacua of massive IIA and AdS6 vacua of IIB, as well as their consistent truncations including vector multiplets. We show that there are no consistent truncations of massive IIA supergravity around its supersymmetric AdS7 vacua with vector multiplets when the Romans mass is non-vanishing. For AdS6 vacua of IIB supergravity, we find that in addition to the consistent truncation to pure F(4) gauged SUGRA, the only other half-maximal truncations that are consistent result in F(4) gauged SUGRA coupled to one or two Abelian vector multiplets, to three non-Abelian vector multiplets, leading to an ISO(3) gauged SUGRA, or to three non-Abelian plus one Abelian vector multiplet, leading to an ISO(3) × U(1) gauged SUGRA. These consistent truncations with vector multiplets exist when the two holomorphic functions that define the AdS6 vacua satisfy certain differential conditions which we derive. We use these to deduce that no globally regular AdS6 solutions admit a consistent truncation to F(4) gauged SUGRA with two vector multiplets, and show that the Abelian T-dual of the Brandhuber-Oz vacuum allows a consistent truncation to F(4) gauged SUGRA with a single vector multiplet.

Holographic duals of five-dimensional SCFTs on a Riemann surface

We study the twisted compactifications of five-dimensional Seiberg SCFTs, with {mathrm{SU}}_{mathrm{mathcal{M}}}(2)times {E}_{N_f}+1 flavor symmetry, on a generic Riemann surface that preserves four supercharges. The five-dimensional SCFTs are obtained from the decoupling limit of N D4-branes probing a geometry of Nf < 8 D8-branes and an O8-plane. In addition to the R-symmetry, we can also twist the flavor symmetry by turning on background flux on the Riemann surface. In particular, in the string theory construction of the five-dimensional SCFTs, the background flux for the SUℳ(2) has a geometric origin, similar to the topological twist of the R-symmetry. We argue that the resulting low-energy three-dimensional theories describe the dynamics on the world-volume of the N D4-branes wrapped on the Riemann surface in the O8/D8 background. The Riemann surface can be described as a curve in a Calabi-Yau three-fold that is a sum of two line bundles over it. This allows for an explicit construction of AdS4 solutions in massive IIA supergravity dual to the world-volume theories, thereby providing strong evidence that the three-dimensional SCFTs exist in the low-energy limit of the compactification of the five-dimensional SCFTs. We compute observables such as the free energy and the scaling dimensions of operators dual to D2-brane probes; these have non-trivial dependence on the twist parameter for the U(1) in SUℳ(2). The free energy exhibits the N5/2 scaling that is emblematic of five-dimensional SCFTs.

Weaving the exotic web

String and M-theory contain a family of branes forming U -duality multiplets. In particular, standard branes with codimension higher than or equal to two, can be explicitly found as supergravity solutions. However, whether domain-wall branes and space-filling branes can be found as supergravity solutions is still unclear. In this paper, we firstly provide a full list of exotic branes in type II string theory or M-theory compactified to three or higher dimensions. We show how to systematically obtain backgrounds of exotic domain-wall branes and space-filling branes as solutions of the double field theory or the exceptional field theory. Such solutions explicitly depend on the winding coordinates and cannot be given as solutions of the conventional supergravity theories. However, as the domain-wall solutions depend linearly on the winding coordinates, we describe them as solutions of deformed supergravities such as the Romans massive IIA supergravity or lower-dimensional gauged supergravities. We establish explicit relations among the domain-wall branes, the mixed-symmetry potentials, the locally non-geometric fluxes, and deformed supergravities.