Flux compactifications of IIA supergravity on orientifolded $$\hbox {G}_2$$ -manifolds have been argued to allow for classical $$\hbox {Minkowski}_3$$ vacua with moduli and scale-separated $$\hbox {AdS}_3$$ vacua with full moduli stabilisation. To further uplift these vacua to meta-stable $$\hbox {dS}_3$$ vacua using anti-D2 branes, warped throats are desirable. We study the flux-stabilisation of local “CGLP-type” throats in compact $$\hbox {G}_2$$ spaces, and discuss consistency constraints on anti-brane uplifting. Despite the classical $$\hbox {AdS}_3$$ vacua being free of tachyons, we find that uplifting from anti-branes down warped throats is forbidden. If instead we rely on hypothetical $$\hbox {AdS}_3$$ vacua that arise from quantum corrections to the classical $$\hbox {Minkowski}_3$$ vacua, we find that (similarly to the 4d analogues) consistency constraints point in opposite directions. However, there is potentially an advantage over 4d when it comes to concrete fine-tuning freedom of numbers, such as tadpole constraints.

Greece

Fotis Farakos

United States

George Tringas

Belgium

Thomas Riet

Warped $$\hbox {G}_2$$ -throats in IIA and uplift dSillusions

We analyze the IIA supergravity solutions corresponding to a warped product of a 3D external Minkowski space and a 7D internal non-compact space, with the latter being the direct product of a deformed conifold and a circle. The specific construction allows for the presence of either a finite 4-cycle or a 3-cycle at the tip supported by the <math altimg='si6.svg'><msub><mi>F</mi><mn>4</mn></msub></math> or the <math altimg='si8.svg'><msub><mi>H</mi><mn>3</mn></msub></math> flux respectively. Once we mod-out by a <math altimg='si9.svg'><msub><mi>Z</mi><mn>2</mn></msub></math> involution we can also get a G2 space, and for completeness we also report on some basic features that we expect from the embedding in a compact setup.

Warped G2 throats from deformed conifolds in IIA supergravity

We study supersymmetric scale-separated AdS flux vacua of massive IIA on G2 orbifolds with smeared orientifold planes. We consider two types of $$ {T}^7/{Z}_2^3 $$ orbifolds which, with appropriate flux choices, yield integer dual dimensions for the operators corresponding to the closed string scalar fields in the dual CFT. As with all other known examples, the dual conformal dimensions are only parametrically close to integer values.

Integer dual dimensions in scale-separated AdS

We argue that scale-separated $$\hbox {AdS}_2$$ vacua with at least two preserved supercharges cannot arise from flux compactifications in a regime of computational control. We deduce this by showing that the $$\hbox {AdS}_2$$ scale is parametrically of the same order as the tension of a fundamental BPS domain wall, which provides an upper bound on the UV cutoff. Since the latter does not need to be associated to any geometric scale, the argument excludes scale separation in a broader sense than what commonly considered. Our claim is exemplified by a bottom-up 2D supergravity analysis as well as top-down models from Type II flux compactifications.

Germany

Niccolò Cribiori

Nikolaos Liatsos

On scale-separated supersymmetric $$\hbox {AdS}_2$$ flux vacua

We revisit the genuine Fayet–Iliopoulos terms of 4D N=1 supergravity. Such terms are commonly believed to preserve a global symmetry, and therefore they are in conflict with the principles of quantum gravity. However, we find that generically there do exist supersymmetric terms that break explicitly the specific global symmetry, while preserving gauge invariance. We illustrate this, by providing a series of examples, including superpotentials and superspace higher order terms, along with a general prescription for their construction.

Alex Kehagias

On global symmetries and Fayet–Iliopoulos terms

We study supersymmetric AdS $$_3$$  <math> <msub> <mrow></mrow> <mn>3</mn> </msub> </math>   flux vacua of massive type-IIA supergravity on anisotropic G2 orientifolds. Depending on the value of the  $$F_4$$  <math> <msub> <mi>F</mi> <mn>4</mn> </msub> </math>   flux the seven-dimensional compact space can either have six small and one large dimension such that the “external” space is scale-separated and effectively four-dimensional, or all seven compact dimensions small and parametrically scale-separated from the three external ones. Within this setup we also discuss the Distance Conjecture (including appropriate D4-branes), and highlight that such vacua provide a non-trivial example of the so-called strong Spin-2 Conjecture.

Spain

Matteo Morittu

Scale-separated AdS $$_3\times $$  <math> <mrow> <msub> <mrow></mrow> <mn>3</mn> </msub> <mo>×</mo> </mrow> </math>  S $$^1$$  <math> <msup> <mrow></mrow> <mn>1</mn> </msup> </math>   vacua from IIA orientifolds

We discuss minimally supersymmetric AdS3 flux vacua of massive type IIA supergravity on G2-orientifolds. We find that configurations with broken scale-separation can be within finite distance from scale-separated ones, while both remain at large volume, weak coupling and have moduli stabilization. The transition is achieved with the use of a D4-brane modulus, which allows the F 4 flux to jump, and has an effective potential always accessible to the three-dimensional low-energy theory. Our analysis further allows us to check the distance conjecture quantitatively, as we can track explicitly the masses of the KK modes.

Italy

France

On/off scale separation

We note that the typical gauge mediation of supersymmetry breaking is in tension with the global limit of the festina lente swampland bound. The alternatives are mediation/breaking schemes that decouple together with gravity, as for example gravity mediation, for which we highlight some basic phenomenological properties. Gauge mediation remains instead a viable mechanism only in models where supersymmetry is restored in the global limit, as for example in no-scale supergravity.

Ioannis Dalianis

Is gauge mediation in the swampland?

We analyze the standard fermionic 4D Volkov–Akulov action with N global non-linear supersymmetries. We find that the stationary points of the system are described by an effective potential, written in terms of two composite real scalar fields, which approaches the exact quantum effective potential in the large N limit. We identify the existence of at least two stationary points, one representing the original supersymmetry breaking configuration and the other one corresponding to goldstino condensation, where supersymmetry is restored in the deep IR.

Goldstino condensation at large N

We investigate the possible appearance of composite states of the goldstino in models with four-dimensional non-linear supersymmetry and we provide a description of their dynamics in terms of a Kähler potential and a superpotential. Our analysis shows that the critical point corresponding to the Volkov-Akulov model is unstable. Similarly, we find that the uplifted stable de Sitter critical point of the KKLT model is shifted and acquires a tachyonic instability. Our findings indicate the existence of a potentially dangerous instability shared by all anti-brane uplifts.