arXiv subjects

Irene Valenzuela

Publications and source records attributed to Irene Valenzuela.

At least 19 recordsLinked to original sources

arXiv2026

Stress-Testing Swampland Bounds with Class S Theories

We test the Sharpened Distance Conjecture (SharpDC) for CFTs, as well as the Refined Distance Conjecture (RDC), in AdS$_5$ gravitational spacetimes, using the CFT dual. The former provides a lower bound on the exponential mass decay rate of the tower of states becoming light at infinite distance in the conformal manifold, while the latter bounds the bulk field range that can be traversed before the exponential behaviour of the tower kicks in. We prove the SharpDC for any large $N$ Lagrangian supersymmetric gauge theory with a finite number $M$ of gauge factors and vanishing one-loop $\beta$-function. We also investigate whether it universally holds in the limits of large central charge, finding that it does not: We exhibit concrete examples in Class S theories where the conjecture is violated in the $M\rightarrow\infty$ limit with $N$ fixed, where the size of the bulk internal geometry is much larger than the AdS curvature scale. We also test the RDC in the moduli space of Class S theories without punctures in the large $N$ limit, showing that it amounts to a precise upper bound on the Weil-Petersson diameter of the moduli space of Riemann surfaces of genus $g$. This bound is consistent with all the mathematical literature up to date, but so far remains unproven.

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arXiv2026

EFT (String) Tower Building

We develop a bottom-up framework to reconstruct the asymptotic spectrum of light towers in four-dimensional $\mathcal{N}=1$ effective field theories directly from their K\"ahler potential. Our construction uses the Integral Scaling Relation, which relates the mass scales of towers becoming light at infinite distance to the tensions of EFT strings, together with the Emergent String Conjecture applied recursively upon decompactification. These conditions organize the tower scaling vectors into a lattice generated by the EFT-string vectors and select the globally consistent tower polytopes. When applied to K\"ahler potentials arising from string compactifications, our algorithm precisely reproduces the known arrangements of towers and duality frames. We then classify the admissible polytopes for asymptotic K\"ahler potentials $K\sim-\log P(s)$, with $P(s)$ a homogeneous polynomial of degree at most seven, and show that certain apparently consistent K\"ahler potentials are incompatible with the assumed quantum-gravity constraints. For general polynomials, additional restrictions arise from gluing the tower arrangements across different growth sectors. Remarkably, every tower polytope allowed by our reconstruction can be obtained as a concrete slice of the polytope associated with M-theory on a Joyce $G_2$-manifold. This provides evidence for a form of string universality in which EFT strings act as the fundamental building blocks of the UV tower structure in the EFT perturbative regimes.

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arXiv2026

The Hitchhiker's Guide to Tensionless String Limits in 4d SCFTs

We study the appearance of universality classes in overall weak-coupling infinite-distance limits in the conformal manifold of 4d ${\cal N}=4,2,1$ superconformal gauge theories at large $N$ and their relation to the type of weakly-coupled emergent string in the AdS bulk dual using brane models. We focus on the complete set of theories with simple gauge group, and provide explicit Hanany-Witten constructions for each of them, including those that have non-Einstein bulk duals. This establishes that the three universality classes found in arXiv:2410.07309 are determined by the number of NS5-branes becoming coincident in a suitable double-scaling limit required to obtain the SCFT. Furthermore, all theories within a given universality class descend from the same parent theory by performing orbifold/orientifold projections (with possibly a small number of extra flavors), which are subleading effects at large $N$. This explains the origin of the universality classes from a CFT perspective. Moreover, we argue that theories in the same universality class share the same closed-string background -- generated by the double-scaled NS5-brane system -- in which the backreaction of D-branes is expected to generate the AdS throat holographically dual to the SCFT. We describe the corresponding worldsheet theories, and find that the three kinds of emergent tensionless strings correspond to the 10d type IIB string, a subcritical string previously studied in a related context, and a novel kind of string which we characterize in detail. Our tools are not limited to this set of SCFTs, but can be naturally applied to more general theories, and allow us to study interpolating models yielding a network of SCFTs related by partial weak-coupling limits. We explicitly discuss the generalization of our results to large classes of theories with more than one gauge factor and even to some quasi-conformal gauge theories.

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arXiv2026

Alice in Warpland: KK modes, Warped Compactifications and the Swampland

We investigate the asymptotic behavior of Kaluza-Klein (KK) towers in warped compactifications to Minkowski space. Focusing on the overall decompactification limit, we derive the scaling of KK masses at large KK momentum for scalar fluctuations in lower-dimensional Planck units. In codimension-one warped backgrounds sourced by a higher-dimensional exponential potential, we solve explicitly for the internal profiles and obtain a closed expression for the exponential mass decay rate $\lambda_{\rm KK}$ of the tower in terms of the moduli space distance. We find that warping reduces $\lambda_{\rm KK}$ relative to the unwarped case, in such a way that sufficiently strong warping could in principle violate the Sharpened Distance Conjecture bound. Remarkably, this sharpened bound is still satisfied precisely when the higher-dimensional potential obeys the condition forbidding asymptotic accelerated expansion, establishing a direct link between the Sharpened Distance Conjecture and the Strong de Sitter condition in one higher dimension. We also argue that for higher-codimension warped backgrounds the asymptotic KK scaling remains unmodified.

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arXiv2025

Neutrinos, B-L Symmetry and the Dark Dimension

We consider realizations of a gauged B-L symmetry in the context of the Dark Dimension scenario, where the SM lives on a codimension one brane in 5d spacetime. The B-L can naturally be a bulk gauge symmetery leading to a global symmetry on the SM brane, and have its gauge anomaly canceled by charged bulk modes. This naturally leads to the existence of 3 right-handed neutrinos propagating in the dark dimension. Allowing for Higgsing of B-L by a bulk scalar at the Higgs scale, results in a massive gauge field with $m_{B-L}\sim 100$ GeV and weak coupling $g_{B-L}\sim 10^{-10}$ which is allowed by current bounds. The model also predicts a natural matching $m_\nu\sim m_{KK}\sim\Lambda^{1/4}$, thereby providing a theoretical explanation for the observed coincidence between neutrino masses and the Dark Energy scale. It also predicts a tower of sterile right-handed neutrinos in the $keV$ mass range.

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arXiv2025

Backtracking AdS flux vacua

We introduce an algorithm (dubbed "flux backtracking") to reverse-engineer the brane picture from an AdS flux vacuum. Given an AdS flux vacuum as input, the algorithm outputs a singularity in 10 or 11 dimensions. This singularity has the property that when probed with the appropriate stack of branes (and after taking the near-horizon limit), one recovers the initial AdS vacuum. After testing the procedure on a number of known AdS/CFT pairs, we apply it to AdS flux vacua without known holographic dual, notably the scale-separated DGKT solution. In this case, flux backtracking produces a certain strongly coupled singularity in massive IIA; we conjecture that the worldvolume CFT of D4-branes probing this singularity should be the holographic CFT dual to DGKT (if it exists). Applying the procedure to the DGKT-related scale-separated AdS$_4$ solutions without Romans mass, we find instead a conical and weakly coupled singularity. We also comment on the results and limitations of applying the procedure to KKLT.

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arXiv2025

EFT strings and dualities in 4d $\mathcal{N}=1$

We investigate the global structure of the states becoming light at perturbative limits of 4d $\mathcal{N}=1$ string and M-theory compactifications, identifying the different duality frames that emerge asymptotically and how they fit together in moduli space. These limits are characterized by the presence of EFT strings - a special class of axionic BPS strings whose tension, derived from the IR K\"ahler potential, vanishes in Planck units at infinite field distance. An intriguing integer scaling relation, $m \sim \mathcal{T}^w$ with $w = \{1,2,3\}$ in Planck units, connects the tension $\mathcal{T}$ of these strings to the mass scale $m$ of the leading tower of states along the string flow. We show that this relation also holds for the subleading towers below the species scale that generate the tower convex hull, implying that their associated $\vec\zeta = -\vec{\nabla} \log m$ vectors lie in a lattice generated by those of the EFT strings. This reveals a striking UV/IR interplay and offers organizing principles for the parametric hierarchies among the relevant UV scales in a given perturbative limit and the web of dualities governing 4d string vacua.

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arXiv2025

Quantum corrections to DGKT and the Weak Gravity Conjecture

We study D4 brane domain walls in the scale-separated 4d $\mathcal{N}$=1 AdS$_4$ DGKT scenario. Classically, these are BPS and satisfy a no-force condition since their tension equals their charge. We show that this property is not stable against quantum corrections and that these increase the brane tension-to-charge ratio, rendering the branes self-attractive. As a result, DGKT seems to be in tension with the Weak Gravity Conjecture for membranes. The quantum effects we consider include non-perturbative gaugino condensation on the D4-brane worldvolume and Euclidean D2 brane instantons, which correct the tension-to-charge ratio because the DGKT construction breaks all parity symmetries. Similar results hold in other 4d $\mathcal{N}$=1 setups not protected by parity symmetries.

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arXiv2025

On Measuring Distances in the Quantum Gravity Landscape

In this note, we propose a generalized notion of distance between vacua in the theory of a scalar field $ϕ$ with scalar potential $V(ϕ)$ coupled to gravity. We propose the normalized tension of domain wall connecting different field values, with a varying normalization relative to a local energy scale, as the distance. We show this definition reproduces the usual moduli space distance for zero potential, as well as the $d\propto |\log Λ|$ behavior with the vacuum energy $Λ$ in the AdS case, previously proposed in the literature. In the case of large AdS we also obtain the expected exponent of mass versus distance in one particular case, when the mass of the light tower is $m\sim \sqrt Λ$ and there is a single extra dimension decompactifying. We also discuss the features and shortcomings of alternative but related proposals.

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arXiv2024

Tensionless String Limits in 4d Conformal Manifolds

Drawing on insights from the Swampland program, we initiate a classification of infinite distance limits in the conformal manifolds of 4d SCFTs. Each limit is characterized by a Hagedorn-like behavior of the large $N$ density of states, which we argue holographically correspond to different tensionless string limits. We focus on 4d large $N$ SCFTs with simple gauge groups, which exhibit an overall free limit at infinite distance within the conformal manifold. In this class of theories, only three types of weak-coupling limits arise. They are distinguished by the exponential rate $α$ of the anomalous dimension of the higher-spin tower, which we find to be determined by the ratio of the central charges $a/c$. We compute the large $N$ partition function at the free point for all these SCFTs, and derive a universal expression for the Hagedorn temperature as a function of $α$ (or, equivalently, of $a/c$), regardless of the gauge group or matter content. This Hagedorn-like density of states suggests that these weak-coupling limits correspond holographically to the tensionless limits of three different strings: the critical Type IIB string and two non-critical strings that arise exclusively in non-Einstein gravitational theories. Our findings are consistent with the Emergent String Conjecture when applied to theories with Einstein gravity at low energies. We also use our results to present a new argument for the absence of scale separation in the holographic AdS bulk dual of these 4d SCFTs. This argument is based on the existence of a bona fide 't Hooft limit, or equivalently, on satisfying the sharpened lower bound for the Distance Conjecture.

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arXiv2024

Taxonomy of Infinite Distance Limits

The Emergent String Conjecture constrains the possible types of light towers in infinite-distance limits in quantum gravity moduli spaces. In this paper, we use these constraints to restrict the geometry of the scalar charge-to-mass vectors $(-\vec{\nabla}\log m)$ of the light towers and the analogous vector $(-\vec{\nabla}\logΛ_{\text{QG}})$ of the species scale. We derive taxonomic rules that these vectors must satisfy in each duality frame. Under certain assumptions, this allows us to classify the ways in which different duality frames can fit together globally in the moduli space in terms of a finite list of polytopes. Many of these polytopes arise in known string theory compactifications, while others suggest either undiscovered corners of the landscape or new swampland constraints.

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arXiv2024

On the Fate of Stringy Non-Invertible Symmetries

Non-invertible symmetries in quantum field theory (QFT) generalize the familiar product rule of groups to a more general fusion rule. In many cases, gauged versions of these symmetries can be regarded as dual descriptions of invertible gauge symmetries. One may ask: are there any other types of non-invertible gauge symmetries? In theories with gravity we find a new form of non-invertible gauge symmetry that emerges in the limit of fundamental, tensionless strings. These stringy non-invertible gauge symmetries appear in standard examples such as non-abelian orbifolds. Moving away from the tensionless limit always breaks these symmetries. We also find that both the conventional form of non-invertible gauge symmetries and these stringy generalizations are realized in AdS/CFT. Although generically broken, approximate non-invertible symmetries have implications for Swampland constraints: in certain cases they can be used to prove the existence of towers of states related to the Distance Conjecture, and can sometimes explain the existence of slightly sub-extremal states which fill in the gaps in the sublattice Weak Gravity Conjecture.

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arXiv2024

Asymptotic Accelerated Expansion in String Theory and the Swampland

We study whether the universal runaway behaviour of stringy scalar potentials towards infinite field distance limits can produce an accelerated expanding cosmology à la quintessence. We identify a loophole to some proposed bounds that forbid such asymptotic (at parametric control) accelerated expansion in 4d $\mathcal{N}=1$ supergravities, by considering several terms of the potential competing asymptotically. We then analyse concrete string theory examples coming from F-theory flux compactifications on Calabi-Yau fourfolds, extending previous results by going beyond weak string coupling to different infinite distance limits in the complex structure moduli space. We find some potential candidates to yield asymptotic accelerated expansion with a flux potential satisfying $γ=\frac{\|\nabla V\|}{V}<\sqrt{2}$ along its gradient flow. However, whether this truly describes an accelerated expanding cosmology remains as an open question until full moduli stabilization including the Kahler moduli is studied. Finally, we also reformulate the condition for forbidding asymptotic accelerated expansion as a convex hull de Sitter conjecture which resembles a convex hull scalar WGC for the membranes generating the flux potential. This provides a pictorial way to quickly determine the asymptotic gradient flow trajectory in multi-moduli setups and the value of $γ$ along it.

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arXiv2023

A Universal Pattern in Quantum Gravity at Infinite Distance

Quantum gravitational effects become significant at a cut-off species scale that can be much lower than the Planck scale whenever we get a parametrically large number of fields becoming light. This is expected to occur at any perturbative limit of an effective field theory coupled to gravity, or equivalently, at any infinite distance limit in the field space of the quantum gravity completion. In this note, we present a universal pattern that links the asymptotic variation rates in field space of the quantum gravity cut-off $Λ_{\text{sp}}$ and the characteristic mass of the lightest tower of states $m$: $\frac{\vec\nabla m}{m} \cdot\frac{\vec\nabla Λ_{\rm sp}}{ Λ_{\rm sp}}=\frac1{d-2}$, where $d$ is the spacetime dimension. This restriction can be used to make more precise several Swampland criteria that constrain the effective field theories that can be consistently coupled to quantum gravity.

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arXiv2023

Stringy Evidence for a Universal Pattern at Infinite Distance

Infinite distance limits in the moduli space of a quantum gravity theory are characterized by having infinite towers of states becoming light, as dictated by the Distance Conjecture in the Swampland program. These towers imply a drastic breakdown in the perturbative regimes of the effective field theory at a quantum gravity cut-off scale known as the species scale. In this paper, we find a universal pattern satisfied in all known infinite distance limits of string theory compactifications, which relates the variation in field space of the mass of the tower and the species scale: $\frac{\vec\nabla m}{m} \cdot\frac{\vec\nabla Λ_{\rm sp}}{ Λ_{\rm sp}}=\frac{1}{d-2}$ in $d$ spacetime dimensions. This implies a more precise definition of the Distance conjecture and sharp bounds for the exponential decay rates. We provide plethora of evidence in string theory and identify some sufficient conditions that allow the pattern to hold from a bottom-up perspective.

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arXiv2023

Running Decompactification, Sliding Towers, and the Distance Conjecture

We study towers of light particles that appear in infinite-distance limits of moduli spaces of 9-dimensional $\mathcal{N}=1$ string theories, some of which notably feature decompactification limits with running string coupling. The lightest tower in such decompactification limits consists of the non-BPS Kaluza-Klein modes of Type I$'$ string theory, whose masses depend nontrivially on the moduli of the theory. We work out the moduli-dependence by explicit computation, finding that despite the running decompactification the Distance Conjecture remains satisfied with an exponential decay rate $α\ge \frac{1}{\sqrt{d-2}}$ in accordance with the sharpened Distance Conjecture. The related sharpened Convex Hull Scalar Weak Gravity Conjecture also passes stringent tests. Our results non-trivially test the Emergent String Conjecture, while highlighting the important subtlety that decompactification can lead to a running solution rather than to a higher-dimensional vacuum.

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arXiv2023

The Dark Dimension and the Swampland

Motivated by principles from the Swampland program, which characterize requirements for a consistent UV completion of quantum gravity, combined with observational data, we are led to a unique corner of the quantum gravity landscape. In particular, using the Distance/Duality conjecture and the smallness of dark energy, we predict the existence of a light tower of states and a unique extra mesoscopic dimension of length $l\sim Λ^{-\frac{1}{4}}\sim 10^{-6}\, m$, with extra massless fermions propagating on it. This automatically leads to a candidate for a tower of sterile neutrinos, and an associated active neutrino mass scale $m_ν\sim \langle H\rangle^2\, Λ^{-\frac{1}{12}}M_{pl}^{-\frac{2}{3}}$. Moreover, assuming the mechanism for stabilization of this dark dimension leads to similar masses for active and sterile neutrinos we are led to the prediction of a Higgs vev $\langle H\rangle \sim Λ^{\frac{1}{6}}M_{pl}^{\frac{1}{3}}$. Another prediction of the scenario is a species scale ${\hat M} \sim Λ^ {\frac{1}{12}}M_{pl}^{\frac{2}{3}}\sim 10^{9}-10^{10} GeV$, corresponding to the higher-dimensional Planck scale. This energy scale may be related to the resolution of the instability of the Higgs effective potential present at a scale of $\sim 10^{11}\, GeV$. We also speculate about the interplay between this energy scale and the GZK limit on ultra-high energy cosmic rays.

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arXiv2022

Large Field Distances from EFT strings

In any consistent effective field theory of quantum gravity limits of infinite field distance are expected to lead to the EFT breakdown due to the appearance of an infinite tower of light states, as predicted by the Distance Conjecture. We review the Distant Axionic String Conjecture, which proposes that any 4d EFT infinite-field-distance limit can be realized as an RG flow of a fundamental axionic string. The RG flow can be understood in terms of the 4d backreaction of such a string, and implies that it becomes tensionless towards the said limit. This property is understood as a shielding mechanism towards realizing an exact axionic symmetry, and it implies the breakdown of the EFT in a way that reproduces the Distance Conjecture. Motivated by string theory data we further propose the Integral Scaling Conjecture, which provides a specific relation between the string tension and the EFT maximal cut-off set by the infinite tower of states.

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