REVIEW
Supersymmetric AdS(4) compactifications of IIA supergravity
High Energy Physics - Theory · Submitted 21 Dec 2004 · 51 references
Pith's verdict: A clean and quotable classification of half-flat N=1 AdS4 vacua in massive IIA, but the 'sufficient' half of the title rests on an integrability step the paper asserts rather than shows for B'≠0.
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Referee report
The paper
The paper claims
The paper derives necessary and sufficient conditions for N=1 compactifications of massive type IIA supergravity to four-dimensional anti-de Sitter space, and shows that every flux is then fixed by the geometry of the internal six-manifold.
The reading
What carries the argument
The engine is the SU(3)-structure decomposition. A single globally defined spinor $η$ on $X_6$ defines a real two-form $J$ and a complex three-form $Ω$, and the failure of these to be closed is packaged into five torsion classes $W_1$ through $W_5$ appearing in $dJ$ and $dΩ$. Every form field is expanded into irreducible SU(3) pieces (a scalar, a vector, an eight, a six, and so on), and the supersymmetry variations are then contracted with gamma matrices to project out each representation one at a time. This turns ten-dimensional Killing-spinor equations into algebraic relations among a handful of numbers, which is what makes the classification tractable.
Extended reading notes
Core claim
The central claim is that N=1 supersymmetric compactifications of (massive) type IIA supergravity to $AdS_4$ are completely characterized by a short list of conditions. The ten-dimensional fields take the form $mB = (f/18)e^{-φ/2}J + m B̃$, $H = (4m/5)e^{7φ/4}Re(Ω)$, and $G = f dVol_4 + (3m/5)e^{φ}J ∧ J$, with constant dilaton, constant warp factor up to a fixed power of $e^{-φ}$, and $B̃$ a primitive two-form. The internal manifold $X_6$ must carry an SU(3) structure whose intrinsic torsion lies entirely in the two classes $W_1^-$ and $W_2^-$, with all other torsion classes vanishing, so $X_6$ is half-flat. An extra condition inherited from the Bianchi identity, $d B̃ ∝ Re(Ω)$, fixes the proportionality constant in terms of the mass and the flux parameter $f$, and forces $f^2 ≥ (108m^2/5)e^{2φ}$. The authors argue that once supersymmetry, the Bianchi identities and the form-field equations are imposed, the dilaton and Einstein equations follow automatically, so no further constraints are needed.
Load-bearing premise
The claim that supersymmetry plus the Bianchi identities plus the form-field equations automatically imply the dilaton and Einstein equations rests on an unproven condition, stated in Section 2 and asserted to hold for the compactifications at hand, that the mixed time-space components of the Einstein tensor vanish.
Editorial extensions
If this is right
- Every flux in the vacuum — the mass parameter, the NS two-form, the RR two- and four-forms — is determined by the torsion data of the internal manifold rather than chosen by hand.
- The internal space is restricted to half-flat manifolds with torsion in $W_1^- ⊕ W_2^-$, a narrower class than the half-flat manifolds allowed by supersymmetry alone.
- In the limit $f^2 = (108m^2/5)e^{2φ}$ the primitive part of the two-form vanishes, all torsion except $W_1^-$ disappears, and the construction collapses to the previously known nearly-Kähler solutions.
- In the massless limit the solution lifts to eleven dimensions as a twisted circle fibration over a half-flat six-manifold, expected to have a three-dimensional conformal field theory dual.
- The results imply that no compactification of eleven-dimensional supergravity to $AdS_4$ on a product of a circle and a six-dimensional nearly-Kähler manifold exists, closing off a case left open in earlier work.
Reading between the lines
- The paper's own two example families — $T^2$ fibrations over K3 and the Iwasawa manifold — satisfy the torsion conditions but miss the required constant in $d B̃ ∝ Re(Ω)$ by a fixed factor, so the authors do not actually exhibit a single fully working solution. Whether the class is nonempty is therefore the live question, not a detail.
- If the class does turn out to be empty, the natural reading is that the Bianchi identity is doing more work than supersymmetry: it is the topology of $X_6$, not the Killing spinor equations, that decides which torsion classes are realizable.
- Because the fluxes are algebraic in the torsion, one could imagine scanning known nilmanifolds and solvmanifolds systematically for the exact proportionality constant, rather than constructing examples one at a time.
- The integrability argument that lets the authors drop the dilaton and Einstein equations is a template that would transfer to other flux backgrounds, so its validity is a claim of broader scope than the specific $AdS_4$ vacua derived here.
Original abstract
We derive necessary and sufficient conditions for N=1 compactifications of (massive) IIA supergravity to AdS(4) in the language of SU(3) structures. We find new solutions characterized by constant dilaton and nonzero fluxes for all form fields. All fluxes are given in terms of the geometrical data of the internal compact space. The latter is constrained to belong to a special class of half-flat manifolds.
The compiled record
The paper's own sentences, arranged, kept beside the review and separate from it. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.
The abstract, sentence by sentence
We derive necessary and sufficient conditions for N=1 compactifications of (massive) IIA supergravity to AdS(4) in the language of SU(3) structures. We find new solutions characterized by constant dilaton and nonzero fluxes for all form fields. All fluxes are given in terms of the geometrical data of the internal compact space. The latter is constrained to belong to a special class of half-flat manifolds.
background contribution method result interpretation main claim
| # | sentence | role | the authors' own work | states the main conclusion | strength |
|---|---|---|---|---|---|
| s0 | We derive necessary and sufficient conditions for N=1 compactifications of (massive) IIA supergravity to AdS(4) in the language of SU(3) structures. | contribution 0.85 | 0.96 | 0.42 | asserted 1.00 |
| s1 | We find new solutions characterized by constant dilaton and nonzero fluxes for all form fields. | result 0.95 | 0.96 | 0.34 | asserted 1.00 |
| s2 | All fluxes are given in terms of the geometrical data of the internal compact space. | result 0.98 | 0.88 | 0.17 | asserted 1.00 |
| s3 | The latter is constrained to belong to a special class of half-flat manifolds. | result 0.98 | 0.78 | 0.19 | asserted 1.00 |
What was examined, and what was not
- arXiv listing abstract v2
- full text
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- references and citing sentences
- relations to other papers
- P abstract
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- T body sentences
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- R cross-paper relations
References
How later papers used it
101 later papers cite it
1 later paper by other authors is listed below: 1 built on it and 1 used its method or tool. It appears under more than one label. 1 more paper by the same authors is listed: 1 built on it.
Builds on it 2 of 6 papers with this label · 1 by the same authors
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Said it needed to understand how the solutions of this paper change in the presence of the O6.
Phenomenology from the Landscape of String Vacua (2008) · 0.98 · paraphrased: the licence does not allow quoting
By the same authors
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Said that its ten-dimensional supergravity picture is contained in the class of solutions of this paper modified by the addition of smeared O6-planes.
AdS4 flux vacua in type II superstrings and their domain-wall solutions (2007) (same authors) · 0.94 · paraphrased: the licence does not allow quoting
Uses its method or tool 1 paper
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Used this paper's decomposition to obtain separate equations for every SU(3) representation in the decomposition of forms.
Phenomenology from the Landscape of String Vacua (2008) · 0.91 · paraphrased: the licence does not allow quoting
How the literature uses it
97 arXiv papers cite this in 175 sentences
Papers citing it · 117 sentences without a confident label
Contests it 1 paper
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However, an $N=1$ supersymmetric $SU(3)$ structure solution requires a constant dilaton [ref] , and a constant dilaton is assumed in [ref] .
M-theory and Type IIA Flux Compactifications · Massive type IIA Supergravity · contest 0.81
Builds on it 5 papers
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Since these vacua must also have O6-planes we need to understand how the solutions of [ref] change in the presence of the O6.
Phenomenology from the Landscape of String Vacua · IIA Supergravity with Orientifolds · 0.98
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This corresponds to a consistent ten-dimensional supergravity picture: it is contained in the class of solutions of [ref] modified by the addition of smeared O6-planes.
AdS4 flux vacua in type II superstrings and their domain-wall solutions · Conclusions · 0.94
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Below we generalise the AdS Ansatz of [ref] and check whether it can give rise to dS$_4$ solutions.
Towards Classical de Sitter Solutions in String Theory · O6 models on $(3)$-structure manifolds · 0.98
Uses its method or tool 1 paper
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In this way, one obtains separate equations for every $SU(3)$ representation in the decomposition of forms [ref] : one can decompose the tensors $F$, $H$ and $G$ in terms of irreducible $SU(3)$ representations.
Phenomenology from the Landscape of String Vacua · Massive Type IIA Supergravity on $AdS_4$ · 0.91
Compares with it 6 papers
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In some cases the solutions are mirror dual to the well known type IIA AdS flux vacua found by DeWolfe, Giryavets, Kachru and Taylor (DGKT) [ref] (see also [ref] for earlier work).
Type IIB flux compactifications with $h^{1,1}=0$ · Introduction · 0.95
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It turns out that this condition leads to a particular set of SU(3)-structure manifolds, nearly-Kähler manifolds, which is a restricted set of solutions with respect to the class of supersymmetric SU(3)-structure backgrounds obtained in [ref] .
New families of scale separated vacua · 4d analysis · 0.99
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The factor of $(-1)^s=±1$ arises in the following equations as unlike [ref] , we have fixed the phase of $Ω$ once and for all in ([ref]); see also [ref] .
Exploiting N=2 in consistent coset reductions of type IIA · The solution · 0.99
Cites it as support 5 papers
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For constant dilaton and warp factor, it was shown in [ref] that, if only the singlets in the torsions are non-zero, no supersymmetric sourceless solutions exist.
N=1 SUSY AdS4 vacua in IIB SUGRA on group manifolds · Conclusion · 0.98
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These configurations are forbidden [ref] because the Ramond-Ramond fluxes induce the non-zero valued NS-NS flux and some torsion classes.
AdS Vacua, Attractor Mechanism and Generalized Geometries · Search of (non)supersymmetric flux attractor vacua · 0.99
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It is important to stress that all the supergravity equations of motion are satifsfied once the above supersymmetry conditions and the RR Bianchi identity ([ref]) are imposed [ref] .
On moduli and effective theory of N=1 warped flux compactifications · Pure spinors, $N=1$ conditions and generalized complex structure · 0.96
Cites it as background 31 papers
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The general class of solutions was derived in [ref] , and later in the language of Generalized Geometry in [ref] .
N=1 SUSY AdS4 vacua in IIB SUGRA on group manifolds · T-duality of (0,0,25,-26,-23,24) · 0.85
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The general form of the 10D supersymmetric solutions was found in [ref] (see also [ref] for earlier work).
Scale-separated AdS$_4$ vacua of IIA orientifolds and M-theory · Scale separation in IIA · 0.95
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This supergravity theory has many (non)supersymmetric solutions of the form $AdS_4×M_6$ [ref] , where $M_6$ represents a six dimensional manifold.
${\cal N}=3$ Supersymmetric Effective Action of D2-branes in Massive IIA String Theory · Conclusion · 0.88
Discussion
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