arXiv subjects

Nicolò Petri

Publications and source records attributed to Nicolò Petri.

At least 19 recordsLinked to original sources

arXiv2026

R7-branes and AdS$_{\text{9}}$ solutions in type IIB

We consider the recently found $\mathrm{AdS}_9$ backgrounds in type IIB supergravity. We start by reviewing the solutions in a more convenient set of coordinates, which allows us to explicitly compute a few relevant observables, including the holographic central charge. Subsequently, we study non-supersymmetric 7-brane configurations sourced by the IIB axio-dilaton. We find explicit analytic 7-brane solutions that possess the above $\mathrm{AdS}_9$ backgrounds as their near-horizon geometry. Finally, we discuss the relation of these 7-brane solutions to the R7 branes by imposing the reflection monodromy $τ\rightarrow -\bar τ$ in the transverse plane.

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arXiv2026

$\text{AdS}_D\times I$ solutions in axio-dilaton gravity

We study non-supersymmetric $\mathrm{AdS}_D\times I$ solutions in the context of $(D+1)$ dimensional gravity coupled to an axio-dilaton with arbitrary runaway potential for the dilaton and arbitrary exponential coupling of the dilaton to the axion kinetic energy. We analyze the equations of motion, reformulate them in terms of a first order autonomous dynamical system, and discuss the set of fixed points, their physical interpretation and their stability conditions. We find a few special classes of analytic solutions for arbitrary $D$, including $\mathrm{AdS}_9\times I$ backgrounds in type IIB supergravity. We conclude by discussing the properties of numerical flows including the massive IIA supergravity case.

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arXiv2026

AdS$_9$ solutions in type II supergravities

We present new solutions in type II supergravities describing AdS$_9$ geometries warped over an interval. In type IIB, we construct an analytic family of backgrounds supported by a non-trivial axio-dilaton profile. Despite the presence of strong-coupling singularities at both ends of the interval, these solutions exhibit both a finite Euclidean on-shell action and a finite holographic central charge. Moreover, they possess a $\mathbb Z_2$ symmetry under which the axion transforms as $C_0\rightarrow -C_0$. We also investigate AdS$_9$ backgrounds in massive IIA supergravity supported by the Romans mass and the dilaton. Numerical integration reveals solutions with a strong-coupling singularity whose asymptotic behavior is consistent with the characteristic D8/O8 profile. In contrast to the type IIB case, our analysis indicates that the Euclidean on-shell action diverges. Finally, we identify a family of perturbative dS$_9$ solutions in massive IIA supergravity.

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arXiv2026

Holographic reconstruction for defect CFTs from $\mathrm{AdS}_p \times S^q$ spacetimes

We study defects in superconformal field theories using holography, focusing on the precise derivation of the defect observables from supergravity. We consider $\mathrm{AdS}_p \times S^q$ spacetimes fibered over an interval and coupled to higher-form gauge fields as well as scalar fields. We determine the coordinate system in which the defect geometry admits an asymptotically flat boundary and, in this setup, we systematically apply holographic renormalization to compute the fundamental observables of the defect theory. In particular, we derive the one-point correlators of the bulk fields, the holographic stress tensor, and its Ward identities. We implement explicitly this procedure for line and surface defects in five- and six-dimensional Romans supergravity. The relevant geometries are $\mathrm{AdS}_2\times S^2$, $\mathrm{AdS}_2\times S^3$ and $\mathrm{AdS}_3\times S^2$ backgrounds warped over an interval, preserving four supercharges and asymptotically $\mathrm{AdS}_5$ and $\mathrm{AdS}_6$. In each case, we discuss the implications of our results and compare them with the standard literature on defects in conformal field theory.

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arXiv2025

Defects in 4d SCFTs from supergravity and holographic renormalization

Type IIB string theory admits Janus solutions connecting $\text{AdS}_5$ vacua. These geometries correspond to interface conformal field theories and are naturally described in five-dimensional supergravity as $\text{AdS}_4$ foliations over an interval. In this work, we introduce a novel type of Janus solution in $\text{AdS}_5$, featuring $\text{AdS}_2 \times S^2$ foliations instead of $\text{AdS}_4$. We interpret these solutions as the supergravity duals of line defects in four-dimensional SCFTs and we discuss their D-brane engineering. Our primary tool is Romans supergravity in five dimensions, which provides a simple Type IIB truncation over $S^5$. Within this framework, under specific conditions, we construct regular solutions interpolating between $\text{AdS}_5$ and $\text{AdS}_2 \times \mathbb{R}^3$. These geometries represent one-parameter deformations of $\text{AdS}_5$ vacua and are characterized by a running profile for two-form gauge potentials and a scalar field in the supergravity bulk. Finally, using holographic renormalization, we explicitly compute the on-shell action of the defect and we discuss the one-point functions in the holographic field theory.

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arXiv2025

Metrics over multi-parameter AdS vacua

We study the notion of a distance between different AdS vacua of string theory. The distance is measured by a metric that is derived by taking an off-shell quadratic variation of the effective action, and evaluating it over families of vacua. We calculate this metric for increasingly complex families of vacua. We first consider the two-parameter families of solutions of type $\mathrm{AdS}_4 \times \mathbb{C}\mathrm{P}^3$. We find that the metric is flat and positive, and so yields a well-defined distance along any path in the space of solutions. We then consider solutions of type $\mathrm{AdS}_3 \times S^3 \times \mathrm{CY}_2$ which have two (non-compact) flux parameters as well as a moduli space. We find that the space of solutions factorises between directions which vary the AdS radius, and the moduli space. The metric over AdS variations is flat and positive, and the metric over the moduli space is the usual one. Finally, we consider solutions of type $\mathrm{AdS}_3 \times S^3 \times S^3 \times S^1$ which also have a further direction in the space of solutions that is compact. We find that the metric is flat only on non-compact directions in the space of solutions. Restricting to such directions, we evaluate the metric and find it is positive definite and therefore yields a well-defined distance along any path.

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arXiv2024

Half-BPS Janus solutions in AdS$_7$

We study half-BPS flows in gauged minimal 7d supergravity featured by an AdS$_3\times S^3$ slicing of the metric, supported by a dyonic three-form field. We first present a novel strategy for analytic integration of the BPS equations, which makes use of the integrals of motion. Subsequently, we discuss the suitable choice of integration constants that gives rise to smooth geometries. These flows are asymptotically locally AdS$_7$ in their UV limit, while their IR geometry is AdS$_3\times \mathbb{R}^4$. We then discuss their uplifts to 11d and massive IIA supergravity and observe that they describe one-parameter deformations of their AdS$_7\times S^4$ and AdS$_7\times S^3$ vacua, respectively, their holographic interpretation being as conformal defect CFT$_2$'s within the corresponding dual SCFT$_6$'s. We conclude with the computation of the holographic central charge, by focussing on the M-theory interpretation.

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arXiv2024

Deconstruction and surface defects in 6d CFTs

We study the two families of AdS$_3\times S^3\times S^2\times Σ_2$ solutions to massive Type IIA supergravity with small and large $(0,4)$ supersymmetries constructed recently in the literature, in connection with the AdS$_7\times S^2\times I$ solutions to massive Type IIA, to which they asymptote locally. Based on our analysis of various observables, that we study holographically, we propose an interpretation of the first class of solutions as dual to deconstructed 6d (1,0) CFTs dual to AdS$_7$, and of the second class as dual to surface defects in the same 6d theories. Among the observables that we study are baryon vertices and giant graviton configurations in quiver-like constructions.

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arXiv2024

Holographic $\frac{1}{2}$-BPS surface defects in ABJM

We study the class of $\text{AdS}_3\times \mathbb{CP}^3$ solutions to massive Type IIA supergravity with $\mathfrak{osp}(6|2)$ superconformal algebra recently constructed in arXiv:2304.12207 [hep-th]. These solutions are foliations over an interval preserving $\mathcal{N}=(0,6)$ supersymmetry in two dimensions, that in the massless limit can be mapped to the $\text{AdS}_4\times \mathbb{CP}^3$ solution of ABJM/ABJ. We show that in the massive case extra NS5-D8 branes, that we interpret as $\frac{1}{2}$-BPS surface defect branes within the ABJ theory, backreact in the geometry and turn one of the 3d field theory directions onto an energy scale, generating a flow towards a 2d CFT. We construct explicit quiver field theories that we propose flow in the IR to the $(0,6)$ SCFTs dual to the solutions. Finally, we show that the $\text{AdS}_3$ solutions realise geometrically, in terms of large gauge transformations, an extension to the massive case of Seiberg duality in ABJ theories proposed in the literature.

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arXiv2024

A positive metric over DGKT vacua

We study the notion of a metric over the space of AdS solution in string theory, leading to an associated distance between them. Such a distance is the idea underlying the AdS distance conjecture. We utilise the previously developed prescription for extracting such a metric: taking an off-shell quadratic variation of the string theory effective action and then evaluating it over the space of on-shell solutions. It was shown that this prescription leads to a well-defined positive metric over M-theory Freund-Rubin vacua. In this work, we use the same prescription to calculate the metric over type IIA DGKT vacua. These are much more involved, they have multiple flux parameters and exhibit scale separation. While it remains an open question whether these vacua exist as fully localised solutions of string theory, they are well-defined within the four-dimensional effective theory, which is all that is required for the calculation. We find that they also have a positive metric over them. Interestingly, this metric turns out to be independent of the many flux parameters in the solution, similarly to what happens for metrics over scalar field spaces. This non-trivial flux cancellation, as well as results from explicit vacua, lead us to propose a Swampland condition: that the metric over the space of vacua in quantum gravity, as defined by the above prescription, is always positive.

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arXiv2023

BBBW on the spindle

We study the spindle compactification of families of AdS$_5$ consistent truncations corresponding to M5 branes wrapped on complex curves in Calabi-Yau three-folds. From the AdS/CFT correspondence these models are dual to $\mathcal{N}=1$ SCFTs obtained by gluing of $T_N$ blocks. The truncations considered here have both vector and hyper multiplets and the analysis of the BPS equations on the spindle allows to extract the central charges. Such analysis gives also consistency conditions for the existence of the solutions. The solutions are then found both analytically and numerically for opportune choices of the charges for some sub-families of truncations. We then compare our results with the one expected from the field theory side, by integrating the anomaly polynomial.

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arXiv2023

Towards AdS Distances in String Theory

The AdS Distance Conjecture proposes to assign a notion of distance between AdS vacua in quantum gravity. We perform some initial developments of this idea. We first propose more sharply how to define a metric on conformal variations of AdS through the action. This metric is negative, making the distance ill-defined, a property relating to the famous conformal factor problem of quantum gravity. However, in string theory, variations of the AdS conformal factor are accompanied by variations of the internal dimensions and of the background flux. We propose an $\textit{action metric}$, which accounts for all of these variations simultaneously. Accounting for the variations of the overall volume of the internal dimensions can flip the sign of the action metric making it positive. This positivity is related to the absence of scale separation between the internal and external dimensions: the negative external conformal contribution must be sub-dominant to the positive internal contribution. We then focus specifically on the families of solutions of eleven-dimensional supergravity on AdS$_4 \times S^7$ and AdS$_7 \times S^4$. For these, there is only a single further additional contribution to the action metric coming from variations of the Freund-Rubin flux. This contribution is subtle to implement, and the unique prescription we find requires singling out the radial direction of AdS as special. Adding the flux contribution yields an overall total action metric which becomes positive for both the AdS$_4$ and AdS$_7$ families of solutions. The final result is therefore a procedure which yields a well-defined distance for these families of solutions.

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arXiv2023

$T^{1,1}$ truncation on the spindle

We study the compactification of the $\mathcal{N}=2$ AdS$_5$ consistent truncation of the conifold, in presence of a Betti vector multiplet, on the spindle. We derive the BPS equations and solve them at the poles, computing the central charge for both the twist and the anti-twist class, turning on the magnetic charge associated to the baryonic symmetry. Then, in the anti-twist class, where there are choices of the quantized flux that give origin to a positive central charge, we numerically solve the BPS equations interpolating between the poles of the spindle. We conclude by comparing our results with the one obtained from the analysis of the dual field theory, finding an exact agreement.

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arXiv2023

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.

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arXiv2022

Line defects as brane boxes in Gaiotto-Maldacena geometries

We construct a new family of $\text{AdS}_2\times S^2\times S^2$ solutions to Type IIA supergravity with 4 supercharges acting with non-Abelian T-duality on the recent class constructed in arXiv:2107.12277. We focus on a particular solution in this class asymptoting locally to an $\text{AdS}_5$ Gaiotto-Maldacena geometry. This solution allows for a line defect interpretation within the 4d $\mathcal{N}=2$ SCFT dual to this geometry, that we study in detail. We show that the defect branes, consisting on a non-trivial intersection of D2-D4-NS5-F1 branes, can be interpreted as baryon vertices within the 4d $\mathcal{N}=2$ SCFT, whose backreaction gives rise to the $\text{AdS}_2$ solution. We construct the explicit quiver quantum mechanics that flows in the IR to the dual SCQM, and show that it can be embedded within the quiver CFT associated to the $\text{AdS}_5$ solution. The quiver quantum mechanics arises from a brane box set-up of D2-branes stretched between perpendicular NS5-branes, that we construct from the $\text{AdS}_2$ solution. We provide non-trivial checks of our proposed duality. Our construction provides one further example of the successful applications of non-Abelian T-duality to holography, in this case in providing a very non-trivial connection between $\text{AdS}_2$ solutions, line defects and brane boxes.

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arXiv2022

AdS$_2$ near-horizons, defects and string dualities

We construct a new family of $\text{AdS}_2\times S^3\times S^2$ solutions to Type IIB supergravity arising as near-horizon geometries of D1-F1-D3-D5-NS5-D7 brane intersections preserving 4 supersymmetries. We show that a subclass of these solutions asymptotes locally to the $\text{AdS}_6\times S^2\times Σ_2$ solution to Type IIB supergravity holographically dual to the five dimensional Sp(N) fixed point theory. This suggests that these solutions can be interpreted as D1-F1-D3 line defects within this CFT. Switching off the D7-branes, we act with $\text{SL}(2, \mathbb{R})$ to construct a second family of solutions that can be related to an $\text{AdS}_3\times S^3\times S^3$ class of M-theory backgrounds describing surface defects within the six dimensional (1,0) SCFT dual to $\text{AdS}_7/\mathbb{Z}_k\times S^4$. Finally, using non-Abelian T-duality we construct new classes of $\text{AdS}_2\times S^2\times S^2$ solutions to Type IIA supergravity with 4 supercharges and elaborate on their M-theory origin.

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arXiv2022

New AdS$_3$/CFT$_2$ pairs in massive IIA with $(0,4)$ and $(4,4)$ supersymmetries

We construct a new class of $\text{AdS}_3\times $S$^3\times $M$_4$ 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 M$_4=$S$^2\times Σ_2$, with $Σ_2$ a 2d Riemann surface, and the geometry is foliated over the $Σ_2$. We interpret these solutions as duals to surface defect CFTs within the 6d $(1,0)$ CFTs dual to the $\text{AdS}_7\times$S$^2\times I$ solutions of massive IIA supergravity. The second subclass is when M$_4=\mathbb{T}^3\times I$ 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 holographically dual to $(4,4)$ 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.

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arXiv2022

Bubbles of nothing and AdS instabilities

In this contribution we review the ideas and results presented in the articles arXiv:2002.01764 and arXiv:2110.08276 where the decay of AdS vacua into bubbles of nothing is studied. We firstly consider AdS vacua in General Relativity with a cosmological constant and in arbitrary dimensions. In this context we study a class of gravitational instantons generalizing the Witten's bubble of nothing and we discuss the derivation of the euclidean action. Secondly we consider a "stringy" non-supersymmetric AdS$_4$ vacuum arising in a compactification of massive IIA supergravity on a $S^6$ and preserving G$_2$ symmetry. This vacuum has been shown to have a fully stable KK spectrum and also be protected against brane-jet decays. In this framework we discuss a bubble solution in massive IIA connected to the G$_2$-invariant vacuum and associated to an instability channel. We finally provide the interpretation of this instability in terms of the nucleation of a bubble of nothing dressed up with a D2 charge distribution.

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