Results for "Ruben Gomez-Ojeda"

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Geometric-based Line Segment Tracking for HDR Stereo SequencesSep 25 2018In this work, we propose a purely geometrical approach for the robust matching of line segments for challenging stereo streams with severe illumination changes or High Dynamic Range (HDR) environments. To that purpose, we exploit the univocal nature of ... More
Memory-induced transition from a persistent random walk to circular motion for achiral microswimmersJul 21 2018We experimentally study the motion of light-activated colloidal microswimmers in a viscoelastic fluid. We find that, in such a non-Newtonian environment, the active colloids undergo an unexpected transition from enhanced angular diffusion to persistent ... More
Learning-based Image Enhancement for Visual Odometry in Challenging HDR EnvironmentsJul 05 2017Apr 09 2018One of the main open challenges in visual odometry (VO) is the robustness to difficult illumination conditions or high dynamic range (HDR) environments. The main difficulties in these situations come from both the limitations of the sensors and the inability ... More
Kronecker Square Roots and The Block vec MatrixOct 08 2013Nov 09 2013Using the block vec matrix, I give a necessary and sufficient condition for factorization of a matrix into the Kronecker product of two other matrices. As a consequence, I obtain an elementary algorithmic procedure to decide whether a matrix has a square ... More
Oscillating Modes of Driven Colloids in Overdamped SystemsFeb 03 2018Microscopic particles suspended in liquids are the prime example of an overdamped system because viscous forces dominate over inertial effects. Apart from their use as model systems, they receive considerable attention as sensitive probes from which forces ... More
Finite forms of Gowers' Theorem on the oscillation stability of $c_0$Dec 17 2013We give a constructive proof of the finite version of Gowers' $FIN_k$ Theorem and analyse the corresponding upper bounds. The $FIN_k$ Theorem is closely related to the oscillation stability of $c_0$. The stabilization of Lipschitz functions on arbitrary ... More
PL-SLAM: a Stereo SLAM System through the Combination of Points and Line SegmentsMay 26 2017Apr 09 2018Traditional approaches to stereo visual SLAM rely on point features to estimate the camera trajectory and build a map of the environment. In low-textured environments, though, it is often difficult to find a sufficient number of reliable point features ... More
Training a Convolutional Neural Network for Appearance-Invariant Place RecognitionMay 27 2015Place recognition is one of the most challenging problems in computer vision, and has become a key part in mobile robotics and autonomous driving applications for performing loop closure in visual SLAM systems. Moreover, the difficulty of recognizing ... More
Automatic Multi-Sensor Extrinsic Calibration for Mobile RobotsJun 11 2019In order to fuse measurements from multiple sensors mounted on a mobile robot, it is needed to express them in a common reference system through their relative spatial transformations. In this paper, we present a method to estimate the full 6DoF extrinsic ... More
An indispensable classification of monomial curves in $\mathbb{A}^4(\mathbbmss{k}) $Mar 24 2011Oct 08 2013In this paper a new classification of monomial curves in $\mathbb{A}^4(\mathbbmss{k})$ is given. Our classification relies on the detection of those binomials and monomials that have to appear in every system of binomial generators of the defining ideal ... More
Fractional Brownian fields, duality, and martingalesDec 22 2006In this paper the whole family of fractional Brownian motions is constructed as a single Gaussian field indexed by time and the Hurst index simultaneously. The field has a simple covariance structure and it is related to two generalizations of fractional ... More
The short resolution of a semigroup algebraDec 01 2015Feb 25 2017This work generalizes the short resolution given in Proc. Amer. Math. Soc. \textbf{131}, 4, (2003), 1081--1091, to any affine semigroup. Moreover, a characterization of Ap\'{e}ry sets is given. This characterization lets compute Ap\'{e}ry sets of affine ... More
Indispensable binomials in semigroup idealsMar 05 2009Feb 22 2010In this paper, we deal with the problem of uniqueness of minimal system of binomial generators of a semigroup ideal. Concretely, we give different necessary and/or sufficient conditions for uniqueness of such minimal system of generators. These conditions ... More
Doubling rational normal curvesDec 15 2008Dec 17 2008In this paper, we study double structures supported on rational normal curves. After recalling the general construction of double structures supported on a smooth curve described in \cite{fer}, we specialize it to double structures on rational normal ... More
An alternative representation of the negative binomial-Lindley distribution. New results and applicationsMar 14 2017In this paper we present an alternative representation of the Negative Binomial--Lindley distribution recently proposed by Zamani and Ismail (2010) which shows some advantages over the latter model. This new formulation provides a tractable model with ... More
A Comprehensive Survey on Parallelization and Elasticity in Stream ProcessingJan 28 2019Jan 29 2019Stream Processing (SP) has evolved as the leading paradigm to process and gain value from the high volume of streaming data produced e.g. in the domain of the Internet of Things. An SP system is a middleware that deploys a network of operators between ... More
Starspots and spin-orbit alignment for Kepler cool host starsNov 08 2012The angle between the spin axis of the host star and the orbit of its planets (i.e., the stellar obliquity) is precious information about the formation and evolution of exoplanetary systems. Measurements of the Rossiter-McLaughlin effect revealed that ... More
Extended function groupsDec 14 2018An structural decomposition of function groups, in terms of the Klein-Maskit combination theorems, was originally provided by Maskit. A similar decomposition works for extended function groups, but such a result it is not easy to find in the literature. ... More
A sufficiently complicated noded Schottky group of rank threeDec 15 2017Jan 09 2018The theoretical existence of non-classical Schottky groups is due to Marden. Explicit examples of such kind of groups are only known in rank two, the first one by by Yamamoto in 1991 and later by Williams in 2009. In 2006, Maskit and the author provided ... More
HDG-NEFEM with degree adaptivity for Stokes flowsJan 20 2018The NURBS-enhanced finite element method (NEFEM) combined with a hybridisable discontinuous Galerkin (HDG) approach is presented for the first time. The proposed technique completely eliminates the uncertainty induced by a polynomial approximation of ... More
Using Disentangled States and Algorithmic Information Theory to Construct a Not P ProblemNov 30 2006Dec 07 2006In this work, are used Chaitin number Omega and the fact that the general decomposition of an N-way disentangled state is an irreducible sentence whose number of coefficients grows in a non-polynomial way with N, to construct a problem that can never ... More
Time-dependent singular differential equationsOct 25 2004A geometric framework for describing and solving time-dependent implicit differential equations F(t,x,x')=0 is studied, paying special attention to the linearly singular case, where F is affine in the velocities: A(t,x)x' = b(t,x). This framework is based ... More
Hyperelliptic quotients of generalized Humbert curvesMay 25 2017A generalized Humbert curve of type $n \geq 4$ is a closed Riemann surface $S$ admitting a group $H \cong {\mathbb Z}_{2}^{n}$ of conformal automorphisms with quotient orbifold ${\mathcal O}=S/H$ having genus zero and exactly $n+1$ cone points. It is ... More
Uniformizations of stable $(γ,n)$-gonal Riemann surfacesMar 09 2017A $(\gamma,n)$-gonal pair is a pair $(S,f)$, where $S$ is a closed Riemann surface and $f:S \to R$ is a degree $n$ holomorphic map onto a closed Riemann surface $R$ of genus $\gamma$. If the signature of $(S,f)$ is of hyperbolic type, then there is pair ... More
Schottky uniformizations of Automorphisms of Riemann surfacesJul 09 2013It is well known that the collection of uniformizations of a closed Riemann surface $S$ is partially ordered; the lowest ones are the Schottky unformizations, that is, tuples $(\Omega,\Gamma,P:\Omega \to S)$, where $\Gamma$ is a Schottky group with region ... More
Uniqueness of Limit Cycles for Quadratic Vector FieldsSep 04 2017This article deals with the study of the number of limit cycles surrounding a critical point of a quadratic planar vector field, which, in normal form, can be written as $x'= a_1 x-y-a_3x^2+(2 a_2+a_5)xy + a_6 y^2$, $y'= x+a_1 y + a_2x^2+(2 a_3+a_4)xy ... More
Factorization invariants in half-factorial affine semigroupsJul 24 2012Let $\mathbb{N} \mathcal{A}$ be the monoid generated by $\mathcal{A} = {\mathbf{a}_1, ..., \mathbf{a}_n} \subseteq \mathbb{Z}^d.$ We introduce the homogeneous catenary degree of $\mathbb{N} \mathcal{A}$ as the smallest $N \in \mathbb N$ with the following ... More
The set of numerical semigroups of a given multiplicity and Frobenius numberApr 11 2019We study the structure of the family of numerical semigroups with fixed multiplicity and Frobenius number. We give an algorithmic method to compute all the semigroups in this family. As an application we compute the set of all numerical semigroups with ... More
A Comment on Masses, Quantum Affine Symmetries and PP-Wave BackgroundsNov 14 2002Jul 04 2003Two dimensional light cone world sheet massive models can be used to define good string backgrounds.In many cases these light cone world sheet lagrangians flow from a CFT in the UV to a theory of massive particles in the IR. The relevant symmetry in the ... More
The Role of Resonances in the Stochastic LimitJul 17 2006In the stochastic limit the resonances play a fundamental role because they determine the generalized susceptivities which are the building blocks of all the physical information which survives in this limit. There are two sources of possible divergences: ... More
A Classification of Fundamental Group Elements Representing simple closed curves on the punctured Klein BottleApr 09 2017In this paper we provide a classification of fundamental group elements representing simple closed curves on the punctured Klein bottle, Similar to the Birman-Series classification of curves on the punctured torus[1]. In the process, an explicit description ... More
Quadratic Feynman Loop Integrands From Massless Scattering EquationsMar 14 2017May 17 2017Recently the Cachazo-He-Yuan (CHY) approach has been extended to loop level, but the resulting loop integrand has propagators that are linear in the loop momentum unlike Feynman's. In this note we present a new technique that directly produces quadratic ... More
One-loop Superstring Amplitude From Integrals on Pure Spinors SpaceOct 18 2009In the Type II superstring the 4-point function for massless NS-NS bosons at one-loop is well known [1][14]. The overall constant factor in this amplitude is very important because it needs to satisfy the unitarity and S-duality conditions [14]. This ... More
Symmetries of handlebodies and their fixed points: Dihedral extended Schottky groupsOct 20 2017A Schottky structure on a handlebody $M$ of genus $g$ is provided by a Schottky group of rank $g$. A symmetry (an orientation-reversing involution) of $M$ is known to have at most $(g+1)$ connected components of fixed points. Each of these components ... More
A Comment on the K-theory Meaning of the Topology of Gauge FixingApr 24 2001Based on the recently discovered K-theory description of D-branes in string theory a K-theory interpretation of the topology of gauge conditions for four dimensional gauge theories, in particular 't Hooft abelian projection, is presented. The interpretation ... More
Elliptic Singularities, θ-Puzzle and Domain WallsNov 11 1997Nov 14 1997We study N=1 four dimensional gluodynamics in the context of M-theory compactifications on elliptically fibered Calabi-Yau fourfolds. Gaugino condensates, \theta-dependence, Witten index and domain walls are considered for singularities of type $\hat{A}_{n-1}$ ... More
Scattering Equations and a new Factorization for Amplitudes I: Gauge TheoriesOct 12 2018Mar 26 2019In this work we show how a double-cover (DC) extension of the Cachazo, He and Yuan formalism (CHY) can be used to provide a new realization for the factorization of the amplitudes involving gluons and scalar fields. First, we propose a graphic representation ... More
Radiative Transport Limit for the Random Schrödinger Equation with Long-Range CorrelationsOct 14 2011In this paper we study the asymptotic phase space energy distribution of solution of the Schr\"{o}dinger equation with a time-dependent random potential. The random potential is assumed to be with slowly decaying correlations. We show that the Wigner ... More
New Exact Supersymmetric Wave Functions for a Massless Scalar Field and Axion-Dilaton String Cosmology in a FRWL MetricMay 10 2019We study the quantum cosmology of the 2D Hawking-Page massless scalar-field model and the homogeneous and isotropic dilation-axion string cosmology.For both models we find new exact solutions for the Wheeler-DeWitt equation and for the supersymmetric ... More
On the number of connected components of the set of fixed points of isometries of geometrically finite hyperbolic manifoldsOct 20 2017Let $M$ be a geometrically finite $m$-dimensional hyperbolic manifold, where $m \geq 2$, and let $G$ be a finite group of its isometries. We provide a formula for the number of connected components of the locus of fixed points of any element of $G$ in ... More
IR Renormalons and Fractional Instantons in SUSY Gauge TheoriesMar 25 2004We study IR-renormalon divergences in N=1 supersymmetric Yang Mills gauge theories and in two dimensional non linear sigma models with mass gap. We derive, in both types of theories, a direct connection between IR- renormalons and fractional instanton ... More
Top Physics Results from CDFMay 30 2005The top quark is by far the most massive fundamental particle observed so far, and the study of its properties is interesting for several reasons ranging from its possible special role in electroweak symmetry breaking to its sensitivity to physics beyond ... More
Wave Propagation in Shallow-Water Acoustic Random WaveguidesNov 30 2009In shallow-water waveguides a propagating field can be decomposed over three kinds of modes: the propagating modes, the radiating modes and the evanescent modes. In this paper we consider the propagation of a wave in a randomly perturbed waveguide and ... More
On the Wilsonian meaning of quantum error correctionApr 24 2019We sketch a recipe to define renormalization group transformations based on Kadanoff-Wilson block packing using a quantum error correction code. In such a case the RG transformations of the couplings are determined by the error matrix of the QEC code. ... More
D-Brane Probes and Mirror SymmetryDec 10 1996We study the effect of mirror symmetry for K3 surfaces on D-brane probe physics. The case of elliptically fibered K3 surfaces is considered in detail. In many cases, mirror can transform a singular fiber of Kodaira's type ADE into sets of singular fibers ... More
Transient dynamics of a colloidal particle driven through a viscoelastic fluidMay 25 2015Sep 17 2015We experimentally study the transient motion of a colloidal particle actively dragged by an optical trap through different viscoelastic fluids (wormlike micelles, polymer solutions, and entangled $\lambda$-phage DNA). We observe that, after sudden removal ... More
Real Structures on Marked Schottky SpaceMar 14 2017Schottky groups are exactly those Kleinian groups providing the regular lowest planar uniformizations of closed Riemann surfaces and also the ones providing to the interior of a handlebody of a complete hyperbolic structure with injectivity radius bounded ... More
Curves which cannot be defined over an extension of degree at most two over the field of moduliMay 29 2012May 31 2012It has been conjectured that every algebraic curve may be defined either over its field of moduli or over an extension of degree two of it. In this paper we provide a negative answer to it by giving examples of hyperelliptic curves which cannot be defined ... More
Probing linear and nonlinear microrheology of viscoelastic fluidsDec 16 2014Bulk rheological properties of viscoelastic fluids have been extensively studied in macroscopic shearing geometries. However, little is known when an active microscopic probe is used to locally perturb them far from the linear-response regime. Using a ... More
Coupling nuclear reaction rates with temperature in explosive conditionsOct 15 2002Oct 16 2002We present a straightforward integration method to compute the abundance and temperature evolution in explosive scenarios. In this approach the thermal equation is implicitely coupled with chemical equations in order to avoid instabilities and ensure ... More
Stellar obliquities and magnetic activities of Planet-Hosting Stars and Eclipsing Binaries based on Transit Chord CorrelationMar 13 2018The light curve of an eclipsing system shows anomalies whenever the eclipsing body passes in front of active regions on the eclipsed star. In some cases, the pattern of anomalies can be used to determine the obliquity $\Psi$ of the eclipsed star. Here ... More
Parametric solutions involving geometry integrated with computer-aided designFeb 25 2019The main objective of this work is to describe a general and original approach for computing an off-line solution for a set of parameters describing the geometry of the domain. That is, a solution able to include information for different geometrical ... More
A locking-free face-centred finite volume (FCFV) method for linear elasticityJun 19 2018A face-centred finite volume (FCFV) method is proposed for the linear elasticity equation. The FCFV is a mixed hybrid formulation, featuring a system of first-order equations, that defines the unknowns on the faces (edges in two dimensions) of the mesh ... More
Towards spin injection from silicon into topological insulators: Schottky barrier between Si and Bi2Se3May 21 2012A scheme is proposed to electrically measure the spin-momentum coupling in the topological insulator surface state by injection of spin polarized electrons from silicon. As a first approach, devices were fabricated consisting of thin (<100nm) exfoliated ... More
Adiabatic Quantum Computing for Binary ClusteringJun 17 2017Quantum computing for machine learning attracts increasing attention and recent technological developments suggest that especially adiabatic quantum computing may soon be of practical interest. In this paper, we therefore consider this paradigm and discuss ... More
Orbital character effects in the photon energy and polarization dependence of pure C60 photoemissionApr 30 2019Recent direct experimental observation of multiple highly-dispersive C$_{60}$ valence bands has allowed for a detailed analysis of the unique photoemission traits of these features through photon energy- and polarization-dependent measurements. Previously ... More
Quasi-projectivity of even Artin groupsMar 14 2018Even Artin groups generalize right-angled Artin groups by allowing the labels in the defining graph to be even. In this paper a complete characterization of quasi-projective even Artin groups is given in terms of their defining graphs. Also, it is shown ... More
An equation of state for purely kinetic k-essence inspired by cosmic topological defectsAug 15 2016Sep 09 2016We investigate the physical properties of a purely kinetic k-essence model with an equation of state motivated in superconducting membranes. We compute the equation of state parameter $w$ and discuss its physical evolution via a nonlinear equation of ... More
Robust regression estimation and inference in the presence of cellwise and casewise contaminationSep 08 2015Dec 26 2016Cellwise outliers are likely to occur together with casewise outliers in modern data sets with relatively large dimension. Recent work has shown that traditional robust regression methods may fail for data sets in this paradigm. The proposed method, called ... More
Radiation Damping of a Yang-Mills Particle RevisitedAug 22 2018Sep 19 2018The problem of a color-charged point particle interacting with a four dimensional Yang-Mills gauge theory is revisited. The radiation damping is obtained inspired in the Dirac's computation. The difficulties in the non-abelian case were solved by using ... More
Probing the energy spectrum of hadrons in proton air interactions at ultrahigh energies through the fluctuations of the muon content of extensive air showersMar 15 2018Jul 12 2018We demonstrate that the shower-to-shower fluctuations of the muon content of extensive air showers correlate with the fluctuations of a variable of the first interaction of Ultra High Energy Cosmic Rays, which is computed from the fraction of energy carried ... More
A matching based clustering algorithm for categorical dataDec 09 2018Cluster analysis is one of the essential tasks in data mining and knowledge discovery. Each type of data poses unique challenges in achieving relatively efficient partitioning of the data into homogeneous groups. While the algorithms for numeric data ... More
Markov-chain approach to a process with long-time memoryOct 08 2001We show that long-term memory effects, present in the chaotic dispersion process generated by a meandering jet model, can be nonetheless taken into account by a first order Markov process, provided that the states of the phase space partition, chosen ... More
Localizations of one-sided exact categoriesMar 26 2019One-sided exact categories were introduced by S. Bazzoni and S. Crivei by weakening the axioms of Quillen exact categories. In this paper, we consider quotients of one-sided exact categories by percolating subcategories. This generalizes the quotient ... More
Action graphs and Catalan numbersFeb 28 2015We introduce an inductively defined sequence of directed graphs and prove that the number of edges added at step $k$ is equal to the $k$th Catalan number. Furthermore, we establish an isomorphism between the set of edges adjoined at step $k$ and the set ... More
The TensorFlow Partitioning and Scheduling Problem: It's the Critical Path!Nov 06 2017State-of-the-art data flow systems such as TensorFlow impose iterative calculations on large graphs that need to be partitioned on heterogeneous devices such as CPUs, GPUs, and TPUs. However, partitioning can not be viewed in isolation. Each device has ... More
MoMIT: Porting a JavaScript Interpreter on a Quarter CoinMay 25 2019The Internet of Things (IoT) is a network of physical, heterogeneous, connected devices providing services through private networks and the Internet. It connects a range of new devices to the Internet so they can communicate with Web servers and other ... More
Dirac form factors and electric charge radii of baryons in the combined chiral and 1/N_c expansionsNov 09 2015The baryon Dirac form factor is computed at one-loop order in large-N_c baryon chiral perturbation theory, where N_c is the number of color charges. Loop graphs with octet and decuplet intermediate states are systematically incorporated into the analysis ... More
Riemann surfaces defined over the realsAug 12 2015May 25 2017The known (explicit) examples of Riemann surfaces not definable over their field of moduli are not real whose field of moduli is a subfield of the reals. In this paper we provide explicit examples of real Riemann surfaces which cannot be defined over ... More
Noded Teichmueller spacesSep 16 2005Let $G$ be a finitely generated Kleinian group and let $\Delta$ be an invariant collection of components in its region of discontinuity. The Teichm\"uller space $T(\Delta,G)$ supported in $\Delta$, is the space of equivalence classes of quasiconformal ... More
Uniform asymptotics for robust location estimates when the scale is unknownOct 05 2004Most asymptotic results for robust estimates rely on regularity conditions that are difficult to verify in practice. Moreover, these results apply to fixed distribution functions. In the robustness context the distribution of the data remains largely ... More
A face-centred finite volume method for second-order elliptic problemsDec 17 2017This work proposes a novel finite volume paradigm, the face-centred finite volume (FCFV) method. Contrary to the popular vertex (VCFV) and cell (CCFV) centred finite volume methods, the novel FCFV defines the solution on the mesh faces (edges in 2D) to ... More
Experimental study of out of equilibrium fluctuations in a colloidal suspension of Laponite using optical trapsDec 07 2008This work is devoted to the study of displacement fluctuations of micron-sized particles in an aging colloidal glass. We address the issue of the validity of the fluctuation dissipation theorem (FDT) and the time evolution of viscoelastic properties during ... More
Measurements of Stellar Inclinations for Kepler Planet Candidates II: Candidate Spin-Orbit Misalignments in Single and Multiple-Transiting SystemsJan 06 2014We present a test for spin-orbit alignment for the host stars of 25 candidate planetary systems detected by the {\it Kepler} spacecraft. The inclination angle of each star's rotation axis was estimated from its rotation period, rotational line broadening, ... More
Measurements of Stellar Inclinations for Kepler Planet CandidatesMay 15 2012Jul 25 2012We present an investigation of spin-orbit angles for planetary system candidates reported by Kepler. By combining the rotational period $P_s$ inferred from the flux variation due to starspots and the projected rotational velocity $V\sin I_s$ and stellar ... More
On pseudo-Frobenius elements of submonoids of $\mathbb{N}^d$Mar 26 2019In this paper we study those submonoids of $\mathbb{N}^d$ which a non-trivial pseudo-Frobenius set. In the affine case, we prove that they are the affine semigroups whose associated algebra over a field has maximal projective dimension possible. We prove ... More
The Globular Cluster System of NGC4374Nov 07 2003We study the globular cluster system (GCS) of the giant elliptical NGC4374 (M84) in the Virgo cluster using B and R photometry. The colour distribution is bimodal with peaks at B-R=1.11 and B-R=1.36, fitting well to those found in other early-type galaxies. ... More
On the integrability of N=2 Landau-Ginzburg models: A graph generalization of the Yang-Baxter equationSep 01 1993The study of the integrability properties of the N=2 Landau- Ginzburg models leads naturally to a graph generalization of the Yang-Baxter equation which synthetizes the well known vertex and RSOS Yang-Baxter equations. A non trivial solution of this equation ... More
Quantum Harmonic Oscillator Algebra and Link InvariantsNov 04 1991The $q$--deformation $U_q (h_4)$ of the harmonic oscillator algebra is defined and proved to be a Ribbon Hopf algebra.Associated with this Hopf algebra we define an infinite dimensional braid group representation on the Hilbert space of the harmonic oscillator, ... More
The Thermodynamics of the living organisms: entropy production in the cellOct 29 2014Trying to identify the entropy production within a cell has been part of debates and studies in the last century. First the idea was to make a resemblance of a cell with a Carnot engine, which is the most thermodynamically perfect machine. This approach ... More
The Confining String from the Soft Dilaton TheoremJul 19 1999Jul 28 1999A candidate for the confining string of gauge theories is constructed via a representation of the ultraviolet divergences of quantum field theory by a closed string dilaton insertion, computed through the soft dilaton theorem. The resulting (critical) ... More
The Most Exigent Eigenvalue: Guaranteeing Consensus under an Unknown Communication Topology and Time DelaysAug 27 2015This document aims to answer the question of what is the minimum delay value that guarantees convergence to consensus for a group of second order agents operating under different protocols, provided that the communication topology is connected but unknown. ... More
Nonequilibrium chiral perturbation theoryFeb 15 1999We explore the extension of chiral perturbation theory out of thermal equilibrium. The pion decay constant becomes then a time-dependent function and we work within the Schwinger-Keldysh contour technique. A useful connection with curved space-time QFT ... More
Holographic flavor in theories with eight superchargesOct 24 2007Nov 28 2007We review the holographic duals of gauge theories with eight supercharges obtained by adding very few flavors to pure supersymmetric Yang-Mills with sixteen supercharges. Assuming a brane-probe limit, the gravity duals are engineered in terms of probe ... More
The Key Elements of Viral Advertising. From Motivation to Emotion in the Most Shared VideosMay 08 2015From its origins in the mid 90s, the application of the concept of virality to commercial communication has represented an opportunity for brands to cross the traditional barriers of the audience concerning advertising and turn it into active communicator ... More
Exact Superpotentials, Theories with Flavor and Confining VacuaMay 26 2004Jul 06 2004In this paper we study some interesting properties of the effective superpotential of N=1 supersymmetric gauge theories with fundamental matter, with the help of the Dijkgraaf--Vafa proposal connecting supersymmetric gauge theories with matrix models. ... More
Masses and electric charges: gauge anomalies and anomalous thresholdsMar 04 2019We study the quantum consistency of a theory with massless electrically charged particles i.e. of massless charged leptons. We show, working in the forward limit, that the KLN cancellation of collinear divergences can only be consistently implemented ... More
Noncommutative cohomology and electromagnetism on $C_q[SL_2]$ at roots of unityOct 31 2001We compute the noncommutative de Rham cohomology for the finite-dimensional q-deformed coordinate ring $C_q[SL_2]$ at odd roots of unity and with its standard 4-dimensional differential structure. We find that $H^1$ and $H^3$ have three additional modes ... More
Separable functors in coringsFeb 15 2001Nov 16 2001We give characterizations of the separability of the induction and ad-induction functors associated to a coring morphism.
Black Holes as Critical Point of Quantum Phase TransitionJul 17 2012We reformulate the quantum black hole portrait in the language of modern condensed matter physics. We show that black holes can be understood as a graviton Bose-Einstein condensate at the critical point of a quantum phase transition, identical to what ... More
Black Hole's 1/N HairMar 29 2012According to the standard view classically black holes carry no hair, whereas quantum hair is at best exponentially weak. We show that suppression of hair is an artifact of the semi-classical treatment and that in the quantum picture hair appears as an ... More
A practical approach to solve coupled systems of nonlinear partial differential equationsMay 23 2008In this paper we present the tanh method to obtain exact solutions to coupled MkDV system. This method may be applied to a variety of coupled systems of nonlinear ordinary and partial differential equations.
The Farrell-Jones Isomorphism Conjecture in K-TheoryFeb 26 2012Mar 10 2012We prove that the Farrell-Jones isomorphism conjecture for non-connective algebraic K-theory for a discrete group G and a coefficient ring R holds true if G belongs to the class of groups acting on trees, under certain conditions on G (see theorem 0.5 ... More
Finite sampling effects on generalized fluctuation-dissipation relations for steady statesFeb 10 2011We study the effects of the finite number of experimental data on the computation of a generalized fluctuation-dissipation relation around a nonequilibrium steady state of a Brownian particle in a toroidal optical trap. We show that the finite sampling ... More
Fluctuations and response in a non-equilibrium micron-sized systemJun 16 2010Nov 30 2010The linear response of non-equilibrium systems with Markovian dynamics satisfies a generalized fluctuation-dissipation relation derived from time symmetry and antisymmetry properties of the fluctuations. The relation involves the sum of two correlation ... More
Non-equilibrium work distribution for interacting colloidal particles under frictionJan 12 2015Mar 25 2015We experimentally investigate the distribution of the non-equilibrium work done by an external force on a mesoscopic system with many coupled degrees of freedom: a colloidal monolayer mechanically driven across a periodic light field. Since this system ... More
New Integrable Deformations of Higher Spin Heisenberg-Ising ChainsMar 12 1992We show that the anisotropic Heisenberg-Ising chains with higher spin allow, for special values of the anisotropy, integrable deformations intimately related to the theory of quantum groups at roots of unity. For the spin one case we construct and study ... More
Nonequilibrium Chiral Dynamics and Effective LagrangiansSep 14 2001We review our recent work on Chiral Lagrangians out of thermal equilibrium, which are introduced to analyse the pion gas formed after a Relativistic Heavy Ion Collision. Chiral Perturbation Theory is extended by letting $\fpi$ be time dependent and allows ... More
Baryonic symmetries in AdS_4/CFT_3: an overviewFeb 27 2011Mar 22 2011Global symmetries play an important role in classifying the spectrum of a gauge theory. In the context of the AdS/CFT duality, global baryon-like symmetries are specially interesting. In the gravity side, they correspond to vector fields in AdS arising ... More
Branes wrapping black holes as a purely gravitational dielectric effectSep 30 2005Jan 13 2006In this paper we give a microscopical description of certain configurations of branes wrapping black hole horizons in terms of dielectric gravitational waves. Interestingly, the configurations are stable only due to the gravitational background. Therefore, ... More