arXiv subjects

Carlos Nunez

Publications and source records attributed to Carlos Nunez.

At least 37 records · Page 2Linked to original sources

arXiv2025

On the stability of holographic confinement with magnetic fluxes

We analyze the stability properties of a simple holographic model for a confining field theory. The gravity dual consists of an Abelian gauge field, with non-trivial magnetic flux, coupled to six-dimensional gravity with a negative cosmological constant. We construct a one-parameter family of regular solitonic solutions, where the gauge field carries flux along a compact circle that smoothly shrinks. The free energy of these solitonic backgrounds is compared to that of domain-wall solutions. This reveals a zero-temperature first-order phase transition in the dual field theory, separating confining and conformal phases. We compute the spectrum of bound states by analysing field fluctuations in the gravity background, after dimensional reduction on the circle. A tachyonic instability emerges near a turning point in the free energy. The phase transition prevents the realisation of this instability. Near the phase transition and beyond, in metastable and unstable regions, we find evidence that the lightest scalar may be interpreted as an approximate dilaton.

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arXiv2024

Linear Quivers at Large-$N$

Quiver theories constitute an important class of supersymmetric gauge theories with well-defined holographic duals. Motivated by holographic duality, we use localisation on $S^d$ to study long linear quivers at large-N. The large-N solution shows a remarkable degree of universality across dimensions, including $d = 4$ where quivers are genuinely superconformal. In that case we upgrade the solution of long quivers to quivers of any length.

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arXiv2024

Holography for Confined and Deformed Theories: TsT-Generated Solutions in type IIB Supergravity

In this paper, we present a series of solutions of type IIB Supergravity, obtained through the TsT deformation of a seed background that is holographically dual to ${\cal N}=4$ Super Yang-Mills theory compactified on a circle (with a twist). We explore various holographic observables, focusing on disentangling the contributions of confinement, marginal deformations, and their interplay. Additionally, we provide a detailed analysis of how certain observables are influenced by the dynamics of the Kaluza-Klein (KK) modes arising from the circle compactification. Our results offer an improved understanding of the connections between the type IIB deformed backgrounds and the dual QFTs.

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arXiv2024

SCFT deformations via uplifted solitons

A holographic method for implementing a particular supersymmetry-preserving deformation to 4d SCFTs is presented. At the heart of the procedure is a soliton solution of minimal $d=5$ gauged supergravity. Embedding this solution into ten- and eleven-dimensional string theory backgrounds of the form AdS$_5 \times M$, we systematically construct a range of new solutions. Each holographically realizes a twisted compactification of the SCFT$_4$ dual to the original background. In the IR, the resulting SQFTs flow to gapped three-dimensional systems. Using a variety of holographic observables, we give evidence for this interpretation and for confinement in the deformed SQFTs. Our method applies to any holographic solutions admitting a consistent truncation to minimal $d=5$ gauged supergravity, and can likely be generalized to solutions with other AdS$_d$ factors.

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arXiv2024

Confinement and screening via holographic Wilson loops

We present the holographic dual to a family of ${\cal N}=1$ SCFTs in four dimensions, deformed by a VEV leading to a gapped system. We calculate Wilson loops in this system containing adjoint, bifundamental and fundamental matter. We calculate the quark-antiquark energy $E$ in terms of their separation $L$, finding an approximate analytic expression for $E(L)$. This expression shows the transition between conformal, confining and screened behaviours. Interesting phenomenology is discussed in a variety of examples. The tool used is the minimization of the F1 string action, for which the code used is made publicly available.

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arXiv2024

Conformal to confining SQFTs from holography

In this paper we present three new families of smooth Type II string theory backgrounds. These are dual to supersymmetry-preserving deformations of 4d SCFTs. The deformations include a VEV for a global current and a `twisted compactification' on a circle. We study various holographic aspects of the dual QFTs, focusing on Wilson loops and Entanglement Entropy. Additionally, we present a monotonic quantity calculating the density of degrees of freedom in terms of the energy, which interpolates between the IR 3d gapped theory and the 4d SCFT result. Other probes related to global aspects of the QFTs are briefly discussed.

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arXiv2024

Marginally deformed AdS$_5$/CFT$_4$ and spindle-like orbifolds

We study marginal deformations of ${\cal N}=2$, $d=4$ long linear quiver CFTs using the holographic description. We find a two-parameter family of AdS$_5$ solutions that generically break all of supersymmetry, but preserve ${\cal N}=1$ for a particular tuning of the parameters. We study the G-structure of the ${\cal N}=2$ "parent" and the ${\cal N}=1$ backgrounds and carefully discuss the quantisation of charges in all cases. For the ${\cal N}=1$ and ${\cal N}=0$ cases, a picture emerges with "branes" back-reacted on either a spindle or its higher dimensional analogue. Comments on the marginally deformed dual CFTs are given, together with the study of some observables.

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arXiv2024

Penrose limits of I-branes, twist-compactified D5-branes and spin chains

In this paper we consider the Penrose limit in the case of two gravity duals. One of them, consists of compactified I-branes (intersecting sets of D5-branes over $(1+1)$ dimensions). The second consists of D5-branes compactified on a circle. Both compactifications preserve SUSY. We find a match of the oscillators and masses of string modes on the resulting pp wave against a spin chain in a $(2+1)-$dimensional field theory in the first case, and a spin chain in a $(1+1)-$dimensional field theory in the second.

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arXiv2024

From conformal to confining field theories using holography

We construct a new family of Type IIB backgrounds that are dual to five dimensional conformal field theories compactified and deformed by VEVs of certain operators. This generates an RG flow into a smooth background dual to non-SUSY gapped field theories in four dimensions. We study various holographic observables: a monotonic quantity associated with the number of degrees of freedom, Wilson loops that interpolate between conformal and confining behaviour with the possibility of screening, Entanglement Entropy, etc. We also give a prescription to compute the Holographic Complexity in this type of backgrounds and calculate the spectrum of spin-two glueballs of the field theories.

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arXiv2024

Confinement and D5 branes

In this work we present new solutions of type IIB supergravity based on wrapped D5 branes. We propose that two of these backgrounds are holographically dual to Quantum Field Theories that confine. The high energy regime of the field theories is that of a Little String Theory. We study various observables (Wilson and 't Hooft loops, Entanglement entropy, density of degrees of freedom and the spectrum of spin-two glueballs, among others). We also present two new black membrane backgrounds and analyse some thermodynamic aspects of these solutions.

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arXiv2023

Confinement in $(1+1)$ dimensions: a holographic perspective from I-branes

In this paper we holographically study the strongly coupled dynamics of the field theory on I-branes (D5 branes intersecting on a line). In this regime, the field theory becomes $(2 + 1)$ dimensional with 16 supercharges. The dual background has an IR singularity. We resolve this singularity by compactifying the theory on a circle, preserving 4 supercharges. We study various aspects: confinement, symmetry breaking, Entanglement Entropy, etc. We also discuss a black membrane solution and make some comments on the string $σ$-model on our backgrounds.

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arXiv2023

Compactification of 6d ${\cal N}=(1,0)$ quivers, 4d SCFTs and their holographic dual Massive IIA backgrounds

In this paper we study an infinite family of Massive Type IIA backgrounds that holographically describe the twisted compactification of ${\cal N}=(1,0)$ six-dimensional SCFTs to four dimensions. The analysis of the branes involved suggests a four dimensional linear quiver QFT, that deconstructs the theory in six dimensions. For the case in which the system reaches a strongly coupled fixed point, we calculate some observables that we compare with holographic results. Two quantities measuring the number of degrees of freedom for the flow across dimensions are studied.

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arXiv2023

Massive flows in AdS$_6$/CFT$_5$

We study five-dimensional ${\cal N}=1$ Superconformal Field Theories of the linear quiver type. These are deformed by a relevant operator, corresponding to a homogeneous mass term for certain matter fields. The free energy is calculated at arbitrary values of the mass parameter. After a careful regularisation procedure, the result can be put in correspondence with a calculation in the supergravity dual background. The F-theorem is verified for these flows, both in field theory and in supergravity. This letter presents some of the results in the companion paper arXiv:2211.13240.

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arXiv2023

Matrix Models and Holography: Mass Deformations of Long Quiver Theories in 5d and 3d

We enlarge the dictionary between matrix models for long linear quivers preserving eight supercharges in $d=5$ and $d=3$ and type IIB supergravity backgrounds with AdS$_{d+1}$ factors. We introduce mass deformations of the field theory that break the quiver into a collection of interacting linear quivers, which are decoupled at the end of the RG flow. We find and solve a Laplace problem in supergravity which realises these deformations holographically. The free energy and expectation values of antisymmetric Wilson loops are calculated on both sides of the proposed duality, finding agreement. Our matching procedure sheds light on the F-theorem in five dimensions.

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arXiv2022

Wilson loops for 5d and 3d conformal linear quivers

Within the electrostatic formulation of holographic duals to (balanced) conformal quivers in five and three dimensions, we study Wilson loops in antisymmetric representations. We derive general expressions for various quantities participating in the formalism (VEV of Wilson loops, representation, gauge-node) and apply these to examples, connecting some results present in the bibliography. In the case of three dimensional quivers, we present a relation between Wilson loops in an 'electric' and in the 'magnetic/mirror' descriptions. In a very detailed appendix, we relate the electrostatic and holomorphic description of the holographic duals to these SCFTS.

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arXiv2021

Holographic description of SCFT$_5$ compactifications

We present three infinite families of supersymmetric Type IIB backgrounds with AdS$_4$, AdS$_3$ and AdS$_2$ factors, dual to SCFTs in $3$, $2$ and $1$ space-time dimensions respectively. These field theories emerge at low energies, after a twisted compactification of a family of five dimensional ${\cal N}=2$ SCFTs on hyperbolic spaces. The holographic flows across dimensions are explicitly computed. We also discuss a family of SUSY breaking backgrounds, dual to a QCD-like quiver with massive (bi)fundamental matter. Some field theoretical observables are computed for these theories at the fixed points and along the flow.

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arXiv2021

Electrostatic description of 3d $\mathcal{N}=4$ linear quivers

We present the holographic dual for the strongly coupled, low energy dynamics of balanced ${\cal N}=4$ field theories in $(2+1)$ dimensions. The infinite family of Type IIB backgrounds with AdS$_4\times S^2\times S^2$ factors is described in terms of a Laplace problem with suitable boundary conditions. The system describes an array of D3, NS5 and D5 branes. We study various aspects of these Hanany--Witten set-ups (number of branes, linking numbers, dimension of the Higgs and Coulomb branches) and encode them in holographic calculations. A generic expression for the Free Energy/Holographic Central Charge is derived. These quantities are then calculated explicitly in various general examples. We also discuss how Mirror Symmetry is encoded in our Type IIB backgrounds. The connection with previous results in the bibliography is made.

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arXiv2021

Electrostatic Description of Five-dimensional SCFTs

In this paper we discuss an infinite class of AdS$_6$ backgrounds in Type IIB supergravity dual to five dimensional SCFTs whose low energy description is in terms of linear quiver theories. The quantisation of the Page charges imposes that each solution is determined once a convex, piece-wise linear function is specified. In the dual field theory, we interpret this function as encoding the ranks of colour and flavour groups in the associated quiver. We check our proposal with several examples and provide general expressions for the holographic central charge and the Wilson loop VEV. Some solutions outside this general class, with less clear quiver interpretation, are also discussed.

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