arXiv subjects

Carlos Nunez

Publications and source records attributed to Carlos Nunez.

At least 55 records · Page 3Linked to original sources

arXiv2021

New AdS$_2$ backgrounds and ${\cal N}=4$ Conformal Quantum Mechanics

We present a new infinite family of Type IIB backgrounds with an AdS$_2$ factor, preserving ${\cal N}=4$ SUSY. For each member of the family we propose a precise dual Super Conformal Quantum Mechanics (SCQM). We provide holographic expressions for the number of vacua (the "central charge"), Chern-Simons terms and other non-perturbative aspects of the SCQM. We relate the "central charge" of the one-dimensional system with a combination of electric and magnetic fluxes in Type IIB. The Ramond-Ramond fluxes are used to propose an extremisation principle for the central charge. Other physical and geometrical aspects of these conformal quantum mechanics are analysed.

hep-th↗

arXiv2021

$\text{AdS}_2\times \text{S}^2\times \text{CY}_2$ solutions in Type IIB with 8 supersymmetries

We present a new infinite family of Type IIB supergravity solutions preserving eight supercharges. The structure of the space is $\text{AdS}_2\times\text{S}^2\times \text{CY}_2\times \text{S}^1$ fibered over an interval. These solutions can be related through double analytical continuations with those recently constructed in \cite{Lozano:2020txg}. Both types of solutions are however dual to very different superconformal quantum mechanics. We show that our solutions fit locally in the class of $\text{AdS}_2\times \text{S}^2\times \text{CY}_2$ solutions fibered over a 2d Riemann surface $Σ$ constructed by Chiodaroli, Gutperle and Krym, in the absence of D3 and D7 brane sources. We compare our solutions to the global solutions constructed by Chiodaroli, D'Hoker and Gutperle for $Σ$ an annulus. We also construct a cohomogeneity-two family of solutions using non-Abelian T-duality. Finally, we relate the holographic central charge of our one dimensional system to a combination of electric and magnetic fluxes. We propose an extremisation principle for the central charge from a functional constructed out of the RR fluxes.

hep-th↗

arXiv2020

AdS$_3$ solutions in Massive IIA with small $\mathcal{N}=(4,0)$ supersymmetry

We study AdS$_3\times \text{S}^2$ solutions in massive IIA that preserve small ${\cal N}=(4,0)$ supersymmetry in terms of an SU(2)-structure on the remaining internal space. We find two new classes of solutions that are warped products of the form AdS$_3\times \text{S}^2\times \text{M}_4\times \mathbb{R}$. For the first, M$_4$=CY$_2$ and we find a generalisation a D4-D8 system involving possible additional branes. For the second, M$_4$ need only be Kahler, and we find a generalisation of the T-dual of solutions based on D3-branes wrapping curves in the base of an elliptically fibered Calabi-Yau 3-fold. Within these classes we find many new locally compact solutions that are foliations of AdS$_3\times \text{S}^2\times\text{CY}_2$ over an interval, bounded by various D brane and O plane behaviours. We comment on how these local solutions may be used as the building blocks of infinite classes of global solutions glued together with defect branes. Utilising T-duality we find two new classes of AdS$_3\times \text{S}^3\times \text{M}_4$ solutions in IIB. The first backreacts D5s and KK monopoles on the D1-D5 near horizon. The second is a generalisation of the solutions based on D3-branes wrapping curves in the base of an elliptically fibered CY$_3$ that includes non trivial 3-form flux.

hep-th↗

arXiv2020

AdS$_2$ duals to ADHM quivers with Wilson lines

We discuss AdS$_2\times S^3\times{\text{CY}}_2\times I_ρ$ solutions to massive Type IIA supergravity with 4 Poincaré supersymmetries. We propose explicit dual quiver quantum mechanics built out of D0 and D4 colour branes coupled to D4' and D8 flavour branes. We propose that these quivers describe the interactions of instantons and Wilson lines in 5d gauge theories with 8 Poincaré supersymmetries. Using the RR Maxwell fluxes of the solutions, conveniently put off-shell, we construct a functional from which the holographic central charge can be derived through a geometrical extremisation principle

hep-th↗

arXiv2020

FuSSI-Net: Fusion of Spatio-temporal Skeletons for Intention Prediction Network

Pedestrian intention recognition is very important to develop robust and safe autonomous driving (AD) and advanced driver assistance systems (ADAS) functionalities for urban driving. In this work, we develop an end-to-end pedestrian intention framework that performs well on day- and night- time scenarios. Our framework relies on objection detection bounding boxes combined with skeletal features of human pose. We study early, late, and combined (early and late) fusion mechanisms to exploit the skeletal features and reduce false positives as well to improve the intention prediction performance. The early fusion mechanism results in AP of 0.89 and precision/recall of 0.79/0.89 for pedestrian intention classification. Furthermore, we propose three new metrics to properly evaluate the pedestrian intention systems. Under these new evaluation metrics for the intention prediction, the proposed end-to-end network offers accurate pedestrian intention up to half a second ahead of the actual risky maneuver.

cs.CV↗

arXiv2020

$M$-strings and AdS$_3$ solutions to M-theory with small $\mathcal{N}=(0,4)$ supersymmetry

We construct a general class of (small) $\mathcal{N}=(0,4)$ superconformal solutions in M-theory of the form AdS$_3\times S^3/\mathbb{Z}_k\times \text{CY}_2$, foliated over an interval. These solutions describe M-strings in M5-brane intersections. The $M$-strings support $(0,4)$ quiver CFTs that are in correspondence with our backgrounds. We compute the central charge and show that it scales linearly with the total number of $M$-strings. We introduce momentum charge, thus allowing for a description in terms of M(atrix) theory. Upon reduction to Type IIA, we find a new class of solutions with four Poincaré supercharges of the form AdS$_2\times S^3\times \text{CY}_2\times \mathcal{I}$, that we extend to the massive IIA case. We generalise our constructions to provide a complete class of AdS$_3$ solutions to M-theory with (0,4) supersymmetry and SU(2) structure. We also construct new $AdS_2\times S^3\times \text{M}_4\times \mathcal{I}$ solutions to massive IIA, with M$_4$ a 4d Kähler manifold and four Poincaré supercharges.

hep-th↗

arXiv2020

Consistent truncations of supergravity and $\frac{1}{2}$-BPS RG flows in $4d$ SCFTs

With the purpose of holographically describing flows from a large family of four dimensional ${\cal N}=1$ and ${\cal N}=2$ conformal field theories, we discuss truncations of seven dimensional supergravity to five dimensions. We write explicitly the reduced gauged supergravity and find BPS equations for simple configurations. Lifting these flows to eleven dimensions or Massive IIA supergravity, we present string duals to RG flows from strongly coupled conformal theories when deformed by marginal and/or relevant operators. We further discuss observables common to infinite families of ${\cal N}=1$ and ${\cal N}=2$ QFTs in this context.

hep-th↗

arXiv2020

Two dimensional ${\cal N}=(0,4)$ quivers dual to AdS$_3$ solutions in massive IIA

In this paper we discuss an infinite family of new solutions in massive Type IIA supergravity with AdS$_3\times$S$^2$ factors, preserving ${\cal N}=(0,4)$ SUSY. After studying geometrical aspects of the backgrounds we propose a duality with a precise family of quivers that flow to (0,4) fixed points at low energies. These quivers consist on two families of (4,4) linear quivers coupled by matter fields. We present various tests of our proposal.

hep-th↗

arXiv2020

1/4 BPS AdS$_3$/CFT$_2$

We discuss new solutions in massive Type IIA supergravity with AdS$_3\times$S$^2$ factors, preserving ${\cal N}=(0,4)$ SUSY. We propose a duality with a precise family of quivers that flow to ${\cal N}=(0,4)$ fixed points at low energies. These quivers consist on two families of linear quivers coupled by matter fields. Physical observables such as the central charges provide stringent checks of the proposed duality. A formal mapping is presented connecting our backgrounds with those dual to six dimensional ${\cal N}=(1,0)$ CFTs, suggesting the existence of a flow across dimensions between the CFTs.

hep-th↗

arXiv2019

AdS$_3$ solutions in massive IIA, defect CFTs and T-duality

We establish a map between AdS$_3 \times$S$^2$ and AdS$_7$ solutions to massive IIA supergravity that allows one to interpret the former as holographic duals to D2-D4 defects inside 6d (1,0) CFTs. This relation singles out in a particular manner the AdS$_3\times$S$^2$ solution constructed from AdS$_3\times$S$^3\times $CY$_2$ through non-Abelian T-duality, with respect to a freely acting SU(2). We find explicit global completions to this solution and provide well-defined (0,4) 2d dual CFTs associated to them. These completions consist of linear quivers with colour groups coming from D2 and D6 branes and flavour groups coming from D8 and D4 branes. Finally, we discuss the relation with flows interpolating between AdS$_3\times$S$^2\times$T$^4$ geometries and AdS$_7$ solutions found in the literature.

hep-th↗

arXiv2019

Integrability and Holographic Aspects of Six-Dimensional ${\cal N}=(1,0)$ Superconformal Field Theories

In the framework of six-dimensional conformal field theories with ${\cal N}=(1,0)$ supersymmetry we develop the map between the holographic description, the field theoretical description and the associated Hanany-Witten set-ups. General expressions that calculate various observables are presented. The study of string solitons singles out a special background of Massive IIA on which we show (by explicitly finding a Lax pair) that the Neveu-Schwarz part of the string sigma model is classically integrable. We study the particular dual conformal field theory and compute some of its observables.

hep-th↗

arXiv2019

Holographic Aspects of Four Dimensional ${\cal N }=2$ SCFTs and their Marginal Deformations

We study the holographic description of ${\cal N}=2$ Super Conformal Field Theories in four dimensions first given by Gaiotto and Maldacena. We present new expressions that holographically calculate characteristic numbers of the CFT and associated Hanany-Witten set-ups, or more dynamical observables, like the central charge. A number of examples of varying complexity are studied and some proofs for these new expressions are presented. We repeat this treatment for the case of the marginally deformed Gaiotto-Maldacena theories, presenting an infinite family of new solutions and compute some of its observables. These new backgrounds rely on the solution of a Laplace equation and a boundary condition, encoding the kinematics of the original conformal field theory.

hep-th↗

arXiv2018

Integrability and non-Integrability in N=2 SCFTs and their Holographic Backgrounds

We show that the string worldsheet theory of Gaiotto-Maldacena holographic duals to N=2 superconformal field theories generically fails to be classically integrable. We demonstrate numerically that the dynamics of a winding string configuration possesses a non-vanishing Lyapunov exponent. Furthermore an analytic study of the Normal Variational Equation fails to yield a Liouvillian solution. An exception to the generic non-integrability of such backgrounds is provided by the non-Abelian T-dual of $AdS_5 \times S^5$. Here by virtue of the canonical transformation nature of the T-duality classical integrability is known to be present.

hep-th↗

arXiv2018

The non-Integrability of Strings in Massive Type IIA and their Holographic duals

In this work we study various aspects of six-dimensional ${\cal N}=(1,0)$ SCFTs. We consider the construction of their string duals in Massive IIA and discuss some observables in given examples. We study the dynamics of string solitons wrapping and rotating on the Massive IIA background and show that the associated Hamiltonian system is both non-integrable and chaotic, implying the non-integrability of the dual CFT. Our procedure is analytic, using well developed mathematical techniques, and numerical, by the explicit calculation of power spectra, Lyapunov coefficients and Poincaré sections.

hep-th↗

arXiv2017

BMN Vacua, Superstars and Non-Abelian T-duality

Acting with non-Abelian T-duality on the $S^3$ inside the $AdS_5$ subspace of $AdS_5\times S^5$ with $N$ units of flux, we generate a new half-BPS solution with $SU(2|4)$ symmetry that belongs to the Lin-Lunin-Maldacena class of geometries. The analysis of the asymptotics, quantised charges and probe branes in this geometry suggests an interpretation as the gravity dual to the Berenstein-Maldacena-Nastase Plane Wave Matrix Model, in a particular vacuum associated to a partition of $N$, in which the multiplicity of each $SU(2)$ irreducible representation is equal to its dimension. This vacuum is interpreted in M-theory in terms of giant gravitons backreacting in the maximally supersymmetric pp-wave geometry. Consistently with this, we show that the non-Abelian T-dual solution exactly agrees with the Penrose limit of the superstar solution in $AdS_7\times S^4$. This suggests an interesting global completion of the non-Abelian T-dual solution in terms of an M5-brane geometry.

hep-th↗

arXiv2017

The $AdS_5$ non-Abelian T-dual of Klebanov-Witten as a $\mathcal{N} = 1$ linear quiver from M5-branes

In this paper we study an $AdS_5$ solution constructed using non-Abelian T-duality, acting on the Klebanov-Witten background. We show that this is dual to a linear quiver with two tails of gauge groups of increasing rank. The field theory dynamics arises from a D4-NS5-NS5' brane set-up, generalizing the constructions discussed by Bah and Bobev. These realize $\mathcal{N}=1$ quiver gauge theories built out of $\mathcal{N}=1$ and $\mathcal{N}=2$ vector multiplets flowing to interacting fixed points in the infrared. We compute the central charge using $a$-maximization, and show its precise agreement with the holographic calculation. Our result exhibits $n^3$ scaling with the number of five-branes. This suggests an eleven-dimensional interpretation in terms of M5-branes, a generic feature of various $AdS$ backgrounds obtained via non-Abelian T-duality.

hep-th↗

arXiv2017

Deriving three-dimensional bosonization and the duality web

Recently, a duality web for three dimensional theories with Chern-Simons terms was proposed. This can be derived from a single bosonization type duality, for which various supporting arguments (but not a proof) were given. Here we explicitly derive this bosonization, in the Abelian case and for a particular regime of parameters. To do this, we use the particle-vortex duality in combination with a Buscher-like duality (both considered in the regime of low energies). As a corollary, Son's conjectured duality is derived in a somewhat singular limit of vanishing mass.

hep-th↗

arXiv2016

Three-dimensional N=4 Linear Quivers and non-Abelian T-duals

In this paper we construct a new Type IIB background with an $AdS_4$ factor that preserves ${\cal N}=4$ Supersymmetry. This solution is obtained using a non-Abelian T-duality transformation on the Type IIA reduction of the $AdS_4\times S^7$ background. We interpret our configuration as a patch of a more general background with localised sources, dual to the renormalisation fixed point of a $T_ρ^{\hatρ} (SU(N))$ quiver field theory. This relates explicitly the $AdS_4$ geometry to a D3-D5-NS5 brane intersection, illuminating what seems to be a more general phenomenon, relating $AdS_{p+1}$ backgrounds generated by non-Abelian T-duality to Dp-D(p+2)-NS5 branes intersections.

hep-th↗