arXiv subjects

Adolfo Guarino

Publications and source records attributed to Adolfo Guarino.

At least 37 records · Page 2Linked to original sources

arXiv2020

Brane-jet stability of non-supersymmetric AdS vacua

We classify the non-supersymmetric, and perturbatively stable within $D=4$, AdS vacua of maximal $D=4$ supergravity with a dyonic ISO(7) gauging in a large sector of the supergravity. Seven such vacua are established within this sector, all of them giving rise to non-supersymmetric $\textrm{AdS}_{4} \times \textrm{S}^{6}$ type IIA backgrounds with and without non-trivial warpings and with internal fluxes. Then, we analyse the dynamics of various probe D$p$-branes in these backgrounds searching for potential brane-jet instabilities. In all these cases, such instabilities are absent. Finally, an alternative decay channel through tunnelling is investigated, focusing on one of the seven backgrounds. We do not find instabilities either, but the analysis remains inconclusive.

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arXiv2020

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

New renormalisation group flows of three-dimensional Chern--Simons theories with a single gauge group $\textrm{SU}(N)$ and adjoint matter are found holographically. These RG flows have an infrared fixed point given by a CFT with $\mathcal{N}=3$ supersymmetry and $\text{SU}(2)$ flavour symmetry. The ultraviolet fixed point is again described by a CFT with either $\mathcal{N}=2$ and $\text{SU}(3)$ symmetry or $\mathcal{N}=1$ and $\text{G}_{2}$ 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.

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arXiv2019

Halving ISO(7) supergravity

Half-maximal, $\,\mathcal{N}=4\,$, sectors of $\,D=4\,$ $\,\mathcal{N}=8\,$ supergravity with a dyonic ISO(7) gauging are investigated. We focus on a half-maximal sector including three vector multiplets, that arises as a certain $\,\textrm{SO}(3)_{\textrm{R}}$-invariant sector of the full theory. We discuss the embedding of this sector into the largest half-maximal sector of the $\,\mathcal{N}=8\,$ supergravity retaining six vector multiplets. We also provide its canonical $\,\mathcal{N}=4\,$ formulation and show that, from this perspective, our model leads in its own right to a new explicit gauging of $\,\mathcal{N}=4\,$ supergravity. Finally, expressions for the restricted duality hierarchy are given and the vacuum structure is investigated. Five new non-supersymmetric AdS vacua are found numerically. The previously known $\,\mathcal{N}=2\,$ and $\,\mathcal{N}=3\,$ AdS vacua are also contained in our $\,\mathcal{N}=4\,$ model. Unlike when embedded in previously considered sectors with fewer fields, these vacua exhibit their full $\,\mathcal{N}=2\,$ and $\,\mathcal{N}=3\,$ supersymmetry within our $\,\mathcal{N}=4\,$ model.

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arXiv2019

S-folds and (non-)supersymmetric Janus solutions

The S-fold description of Janus-type solutions of type IIB supergravity is investigated. This is done by first studying a $\,\textrm{U}(1) \times \textrm{U}(1)\,$ invariant sector of the four-dimensional dyonically-gauged $\,{[\,\textrm{SO}(1,1) \times \textrm{SO}(6)\,] \ltimes \mathbb{R}^{12}}\,$ maximal supergravity that arises upon reduction of type IIB supergravity on $\,\mathbb{R} \, \times \, \textrm{S}^{5}\,$. Two AdS$_{4}$ solutions preserving $\,\textrm{SU}(3)\,$ and $\,\textrm{SO}(6)\,$ gauge symmetry together with $\,\mathcal{N}=1\,$ and $\,\mathcal{N}=0\,$ supersymmetry are found within this sector. Fetching techniques from the E$_{7(7)}$ exceptional field theory, these solutions are uplifted to ten-dimensional S-folds of type IIB Janus-type solutions of the form $\,\textrm{AdS}_{4} \times \mathbb{R} \times \textrm{M}_{5}\,$. The solutions presented here are natural candidates for the holographic duals of three-dimensional $\,\mathcal{N}=1\,$ and $\,\mathcal{N}=0\,$ interface super-Yang--Mills theories with $\,\textrm{SU}(3)\,$ and $\,\textrm{SU}(4)\,$ internal symmetry.

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arXiv2019

Hypermultiplet gaugings and supersymmetric solutions from 11D and massive IIA supergravity on H$^{(p,q)}$ spaces

Supersymmetric $\,\textrm{AdS}_{4}\,$, $\,\textrm{AdS}_{2} \times Σ_{2}\,$ and asymptotically AdS$_{4}$ black hole solutions are studied in the context of non-minimal $\,\mathcal{N}=2\,$ supergravity models involving three vector multiplets (STU-model) and Abelian gaugings of the universal hypermultiplet moduli space. Such models correspond to consistent subsectors of the $\,\textrm{SO}(p,q)\,$ and $\,\textrm{ISO}(p,q)\,$ gauged maximal supergravities that arise from the reduction of 11D and massive IIA supergravity on $\,\textrm{H}^{(p,q)}\,$ spaces down to four dimensions. A unified description of all the models is provided in terms of a square-root prepotential and the gauging of a duality-hidden symmetry pair of the universal hypermultiplet. Some aspects of M-theory and massive IIA holography are mentioned in passing.

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arXiv2018

BPS black hole horizons from massive IIA

The maximal four-dimensional supergravity with a dyonic ISO(7) gauging that arises from the reduction of massive IIA on a six-sphere has recently been shown to accommodate static BPS black holes with hyperbolic horizons. When restricted to the N=2 subsector that retains one vector multiplet and the universal hypermultiplet, the attractor mechanism was shown to fix both the vector charges and the scalar fields at the horizon to a unique configuration in terms of the gauging parameters. In order to assess the (non-)uniqueness of BPS black hole horizons from massive IIA, we extend the study of the attractor mechanism to other N=2 subsectors including additional matter multiplets. We note that, while extending the hypermultiplet sector does not modify the set of solutions to the attractor equations, the inclusion of additional vector multiplets results in new hyperbolic/spherical horizons containing free parameters. The model with three vector multiplets and the universal hypermultiplet, which is the massive IIA analogue of the STU-model from M-theory, may play a relevant role in massive IIA holography.

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arXiv2017

BPS black holes from massive IIA on S$^6$

We present BPS black hole solutions in a four-dimensional $\mathcal{N}=2$ supergravity with an abelian dyonic gauging of the universal hypermultiplet moduli space. This supergravity arises as the SU(3)-invariant subsector in the reduction of massive IIA supergravity on a six-sphere. The solutions are supported by non-constant scalar, vector and tensor fields and interpolate between a unique $\textrm{AdS}_{2} \,\times\, \textrm{H}^2$ geometry in the near-horizon region and the domain-wall DW$_{4}$ (four-dimensional) description of the D2-brane at the boundary. Some special solutions with charged AdS$_{4}$ or non-relativistic scaling behaviours in the ultraviolet are also presented.

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arXiv2016

Double Field Theory at SL(2) angles

An extended field theory is presented that captures the full SL(2) x O(6,6+n) duality group of four-dimensional half-maximal supergravities. The theory has section constraints whose two inequivalent solutions correspond to minimal D=10 supergravity and chiral half-maximal D=6 supergravity, respectively coupled to vector and tensor multiplets. The relation with O(6,6+n) (heterotic) double field theory is thoroughly discussed. Non-Abelian interactions as well as background fluxes are captured by a deformation of the generalised diffeomorphisms. Finally, making use of the SL(2) duality structure, it is shown how to generate gaugings with non-trivial de Roo-Wagemans angles via generalised Scherk-Schwarz ansaetze. Such gaugings allow for moduli stabilisation including the SL(2) dilaton.

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arXiv2016

The exceptional story of massive IIA supergravity

The framework of exceptional field theory is extended by introducing consistent deformations of its generalised Lie derivative. For the first time, massive type IIA supergravity is reproduced geometrically as a solution of the section constraint. This provides a unified description of all ten- and eleven-dimensional maximal supergravities. The action of the E7 deformed theory is constructed, and reduces to those of exceptional field theory and gauged maximal supergravity in respective limits. The relation of this new framework to other approaches for generating the Romans mass non-geometrically is discussed.

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arXiv2016

Romans-mass-driven flows on the D2-brane

The addition of supersymmetric Chern-Simons terms to ${\cal N}=8$ super-Yang-Mills theory in three-dimensions is expected to make the latter flow into infrared superconformal phases. We address this problem holographically by studying the effect of the Romans mass on the D2-brane near-horizon geometry. Working in a consistent, effective four-dimensional setting provided by $D=4$ ${\cal N}=8$ supergravity with a dyonic $\textrm{ISO(7)}$ gauging, we verify the existence of a rich web of supersymmetric domain walls triggered by the Romans mass that interpolate between the (four-dimensional description of the) D2-brane and various superconformal phases. We also construct domain walls for which both endpoints are superconformal. While most of our results are numerical, we provide analytic results for the $\textrm{SU}(3)\times \textrm{U}(1)$-invariant flow into an ${\cal N}=2$ conformal phase recently discovered.

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arXiv2016

CSO$_c$ superpotentials

Motivated by their application to holographic RG flows and hairy black holes in Einstein-scalar systems, we present a collection of superpotentials driving the dynamics of $\mathcal{N}=2$ and $\mathcal{N}=1$ four-dimensional supergravities. These theories arise as consistent truncations of the electric/magnetic families of $\textrm{CSO}(p,q,r)_{c}$ maximal supergravities, with ${p+q+r=8}$, discovered by Dall'Agata et al. The $\mathcal{N}=2$ and $\mathcal{N}=1$ truncations describe $\textrm{SU}(3)$ and $\mathbb{Z}_{2} \times \textrm{SO}(3)$ invariant sectors, respectively, and contain AdS$_4$ solutions preserving $\mathcal{N}=1,2,3,4$ supersymmetry within the full theories, as well as various gauge symmetries. Realisations in terms of non-geometric type IIB as well as geometric massive type IIA backgrounds are also discussed. The aim of this note is to provide easy to handle superpotentials that facilitate the study of gravitational and gauge aspects of the $\textrm{CSO}(p,q,r)_{c}$ maximal supergravities avoiding the technicalities required in their construction.

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arXiv2016

Single-step de Sitter vacua from non-perturbative effects with matter

A scenario of moduli stabilisation based on the interplay between closed and open string sectors is explored in a bottom-up approach. We study N=1 effective supergravities inspired by type IIB orientifold constructions that include background fluxes and non-perturbative effects. The former generate the standard flux superpotential for the axiodilaton and complex structure moduli. The latter can be induced by gaugino condensation in a non-Abelian sector of D7-branes and involve the overall Kaehler modulus of the compactification as well as matter fields. We analyse the dynamics of this coupled system and show that it is compatible with single-step moduli stabilisation in a metastable de Sitter vacuum. A novelty of the scenario is that the F-term potential suffices to generate a positive cosmological constant and to stabilise all moduli, except for a flat direction that can be either lifted by a mass term or eaten up by an anomalous U(1).

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arXiv2016

Dyonic ISO(7) supergravity and the duality hierarchy

Motivated by its well defined higher dimensional origin, a detailed study of $D=4$ $\mathcal{N}=8$ supergravity with a dyonically gauged $\textrm{ISO}(7) = \textrm{SO}(7) \ltimes \mathbb{R}^7$ gauge group is performed. We write down the Lagrangian and describe the tensor and duality hierarchies, focusing on an interesting subsector with closed field equations and supersymmetry transformations. We then truncate the $\mathcal{N}=8$ theory to some smaller sectors with $\mathcal{N}=2$ and $\mathcal{N}=1$ supersymmetry and SU(3), $\textrm{G}_2$ and SO(4) bosonic symmetry. Canonical and superpotential formulations for these sectors are given, and their vacuum structure and spectra is analysed. Unlike the purely electric ISO(7) gauging, the dyonic gauging displays a rich structure of vacua, all of them AdS. We recover all previously known ones and find a new $\mathcal{N}=1$ vacuum with SU(3) symmetry and various non-supersymmetric vacua, all of them stable within the full $\mathcal{N}=8$ theory.

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arXiv2015

Consistent ${\cal N}=8$ truncation of massive IIA on $S^6$

Massive type IIA supergravity is shown to admit a consistent truncation on the six-sphere to maximal supergravity in four dimensions with a dyonic ISO(7) gauging. We obtain the complete, non-linear embedding of all the $D=4$ fields into the IIA metric and form potentials, and show its consistency. We first rewrite the IIA theory in an $\textrm{SO}(1,3) \times \textrm{SL}(7)$--covariant way. Then, we employ an ${\cal N}=8$ SL(7)--covariant restriction of the $D=4$ tensor hierarchy in order to find the full embedding. The redundant $D=4$ degrees of freedom introduced by the tensor hierarchy can be eliminated by writing the embedding in terms of the field strengths and exploiting the restricted duality hierarchy. In particular, closed expressions for the Freund-Rubin term are found using this technique which reveal a pattern valid for other truncations. Finally, we show that the present ${\cal N}=8$ truncation of massive IIA on $S^6$ and the ${\cal N}=2$ truncation obtained when $S^6$ is equipped with its nearly-Kähler structure, overlap in the ${\cal N}=1$, G$_2$--invariant sector of the former.

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arXiv2015

The string origin of dyonic ${\cal N}=8$ supergravity and its simple Chern-Simons duals

We clarify the higher-dimensional origin of a class of dyonic gaugings of $D=4$ ${\cal N}=8$ supergravity recently discovered, when the gauge group is chosen to be ISO(7). This dyonically-gauged maximal supergravity arises from consistent truncation of massive IIA supergravity on $S^6$, and its magnetic coupling constant descends directly from the Romans mass. The critical points of the supergravity uplift to new AdS$_4$ massive type IIA vacua. We identify the corresponding CFT$_3$ duals as super-Chern-Simons-matter theories with simple gauge group SU$(N)$, with level $k$ given by the Romans mass. In particular, we find a critical point that uplifts to the first explicit ${\cal N}=2$ AdS$_4$ massive IIA background. We compute its free energy and that of the candidate dual Chern-Simons theory by localisation to a solvable matrix model, and find perfect agreement. This provides the first AdS$_4$/CFT$_3$ precision match in massive type IIA string theory.

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arXiv2015

On new maximal supergravity and its BPS domain-walls

We revise the SU(3)-invariant sector of $\mathcal{N}=8$ supergravity with dyonic SO(8) gaugings. By using the embedding tensor formalism, analytic expressions for the scalar potential, superpotential(s) and fermion mass terms are obtained as a function of the electromagnetic phase $ω$ and the scalars in the theory. Equipped with these results, we explore non-supersymmetric AdS critical points at $ω\neq 0$ for which perturbative stability could not be analysed before. The $ω$-dependent superpotential is then used to derive first-order flow equations and obtain new BPS domain-wall solutions at $ω\neq 0$. We numerically look at steepest-descent paths motivated by the (conjectured) RG flows.

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arXiv2015

KK-monopoles and G-structures in M-theory/type IIA reductions

We argue that M-theory/massive IIA backgrounds including KK-monopoles are suitably described in the language of G-structures and their intrinsic torsion. To this end, we study classes of minimal supergravity models that admit an interpretation as twisted reductions in which the twist parameters are not restricted to satisfy the Jacobi constraints $ω\, ω=0$ required by an ordinary Scherk-Schwarz reduction. We first derive the correspondence between four-dimensional data and torsion classes of the internal space and, then, check the one-to-one correspondence between higher-dimensional and four-dimensional equations of motion. Remarkably, the whole construction holds regardless of the Jacobi constraints, thus shedding light upon the string/M-theory interpretation of (smeared) KK-monopoles.

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arXiv2014

A second look at gauged supergravities from fluxes in M-theory

We investigate reductions of M-theory beyond twisted tori by allowing the presence of KK6 monopoles (KKO6-planes) compatible with N=4 supersymmetry in four dimensions. The presence of KKO6-planes proves crucial to achieve full moduli stabilisation as they generate new universal moduli powers in the scalar potential. The resulting gauged supergravities turn out to be compatible with a weak G2 holonomy at N=1 as well as at some non-supersymmetric AdS4 vacua. The M-theory flux vacua we present here cannot be obtained from ordinary type IIA orientifold reductions including background fluxes, D6-branes (O6-planes) and/or KK5 (KKO5) sources. However, from a four-dimensional point of view, they still admit a description in terms of so-called non-geometric fluxes. In this sense we provide the M-theory interpretation for such non-geometric type IIA flux vacua.

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