Results for "R. R. Francisco"

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Self-similar Radiation from Numerical Rosenau-Hyman CompactonsAug 03 2007The numerical simulation of compactons, solitary waves with compact support, is characterized by the presence of spurious phenomena, as numerically-induced radiation, which is illustrated here using four numerical methods applied to the Rosenau-Hyman ... More
Hard thermal loops in long wave-length and static external gravitational fieldsJan 10 2013We study, in the long wave-length and static limits, the structure of the n-point graviton functions at high temperature. Using the gauge and Weyl invariance of the theory, we derive a simple expression for the hard thermal amplitudes in these two limits. ... More
A curious arithmetic of fractal dimension for polyadic Cantor setsOct 27 2009Fractal sets, by definition, are non-differentiable, however their dimension can be continuous, differentiable, and arithmetically manipulable as function of their construction parameters. A new arithmetic for fractal dimension of polyadic Cantor sets ... More
Removing trailing tails and delays induced by artificial dissipation in Padé numerical schemes for stable compacton collisionsSep 10 2012The numerical simulation of colliding solitary waves with compact support arising from the Rosenau-Hyman K(n,n) equation requires the addition of artificial dissipation for stability in the majority of methods. The price to pay is the appearance of trailing ... More
Numerical interactions between compactons and kovatons of the Rosenau-Pikovsky K(cos) equationAug 16 2012A numerical study of the nonlinear wave solutions of the Rosenau-Pikovsky K(cos) equation is presented. This equation supports at least two kind of solitary waves with compact support: compactons of varying amplitude and speed, both bounded, and kovatons ... More
Lattice Deformation, Low Energy Models and Flat Bands in Twisted Graphene BilayersMar 01 2019Twisted graphene bilayers show a complex electronic structure, further modified by interaction effects. The main features can be obtained from effective models, which make use a few phenomenological parameters. We analyze the influence of effects at the ... More
Recovery Risk: Application of the Latent Competing Risks Model to Non performing LoansAug 19 2014This article proposes a method for measuring the latent risks involved in the recovery process of non performing loans in financial institutions and business firms that deal with collection and recovery processes. To that end, we apply the competing risks ... More
Continuum models for twisted bilayer graphene: the effects of lattice deformation and hopping parameterMar 01 2019We analyze a description of twisted graphene bilayers, that incorporates deformation of the layers due to the nature modern interlayer potentials, and a modification of the hopping parameters between layers in the light of the classic Slonczewski-Weiss-McClure ... More
Electrostatic effects, band distortions and superconductivity in twisted graphene bilayersJun 15 2018Dec 12 2018Bilayer graphene twisted by a small angle shows a significant charge modulation away from neutrality, as the charge in the narrow bands near the Dirac point is mostly localized in the regions of the Moir\'e pattern with $AA$ stacking. The resulting electrostatic ... More
Interaction between point charges, dipoles and graphene layersMay 26 2016We analyse the interaction between charges and graphene layers. The electric polarisability of graphene induces a force, that can be described by an image charge. The analysis shows that graphene can be described as an imperfect conductor with a finite ... More
An Evidence of Link between Default and Loss of Bank Loans from the Modeling of Competing RisksAug 19 2014In this paper, we propose a method that provides a useful technique to compare relationship between risks involved that takes customer become defaulter and debt collection process that might make this defaulter recovered. Through estimation of competitive ... More
Dissipative perturbations for the K(n,n) Rosenau-Hyman equationAug 20 2012Compactons are compactly supported solitary waves for nondissipative evolution equations with nonlinear dispersion. In applications, these model equations are accompanied by dissipative terms which can be treated as small perturbations. We apply the method ... More
Causal amplitudes in the Schwinger model at finite temperatureJun 25 2012Jul 13 2012We show, in the imaginary time formalism, that the temperature dependent parts of all the retarded (advanced) amplitudes vanish in the Schwinger model. We trace this behavior to the CPT invariance of the theory and give a physical interpretation of this ... More
Tunnelling in quantum superlattices with variable lacunarityFeb 05 2007Feb 08 2007Quantum fractal superlattices are microelectronic devices consisting of a series of thin layers of two semiconductor materials deposited alternately on each other over a substrate following the rules of construction of a fractal set, here, a symmetrical ... More
Quantum corrections to the geodesic equationMar 25 1999In this talk we will argue that, when gravitons are taken into account, the solution to the semiclassical Einstein equations (SEE) is not physical. The reason is simple: any classical device used to measure the spacetime geometry will also feel the graviton ... More
Creation of photons in an oscillating cavity with two moving mirrorsOct 29 1998We study the creation of photons in a one dimensional oscillating cavity with two perfectly conducting moving walls. By means of a conformal transformation we derive a set of generalized Moore's equations whose solution contains the whole information ... More
A Quantum Mechanics Analogy for the Nonlinear Schrödinger Equation in the Finite LineJan 16 2013A quantum mechanics analogy is used to determine the forces acting on and the energies of solitons governed by the nonlinear Schr\"odinger equation in finite intervals with periodic and with homogeneous Dirichlet, Neumann and Robin boundary conditions. ... More
Geodesics, gravitons and the gauge fixing problemAug 19 1997When graviton loops are taken into account, the background metric obtained as a solution to the one-loop corrected Einstein equations turns out to be gauge fixing dependent. Therefore it is of no physical relevance. Instead we consider a physical observable, ... More
Renormalization Group Approach to the Dynamical Casimir EffectOct 21 1997In this paper we study the one dimensional dynamical Casimir effect. We consider a one dimensional cavity formed by two mirrors, one of which performs an oscillatory motion with a frequency resonant with the cavity. The naive solution, perturbative in ... More
Quantum corrected geodesicsApr 20 1999We compute the graviton-induced corrections to the trajectory of a classical test particle. We show that the motion of the test particle is governed by an effective action given by the expectation value (with respect to the graviton state) of the classical ... More
The Nonlinear Schrödinger Equation in the Finite LineJan 17 2013A numerical study of the nonlinear Schr\"odinger (NLS) equation subject to homogeneous Dirichlet, Neumann and Robin boundary conditions in the finite line is presented. The results are compared with both the exact analytical ones for the initial-value ... More
Hund nodal line semimetals: The case of twisted magnetic phase in the double-exchange modelMay 09 2018Jan 26 2019We propose a class of topological metals, which we dub \emph{Hund nodal line semimetals}, arising from the strong Coulomb interaction encoded in the Hund's coupling between itinerant electrons and localized spins. We here consider a particular twisted ... More
Exact CTP Renormalization Group Equation for the Coarse Grained Effective ActionMay 03 1996Nov 11 1996We consider a scalar field theory in Minkowski spacetime and define a coarse grained Closed Time Path (CTP) effective action by integrating quantum fluctuations of wavelengths shorter than a critical value. We derive an exact CTP renormalization group ... More
Puzzles in hadronic transitions of heavy quarkonium with two pion emissionSep 24 2014Oct 09 2014We study the anomalously large rates of some hadronic transitions observed in heavy quarkonia using a constituent quark model which has been successful in describing meson and baryon phenomenology. QCD multipole expansion (QCDME) is used to described ... More
Classical Forces on Solitons in Finite and Infinite, Nonlinear, Planar WaveguidesJan 16 2013Conservation equations for the mass, linear momentum and energy densities of solitons propagating in finite, infinite and periodic, nonlinear, planar waveguides and governed by the nonlinear Schr\"odinger equation are derived. These conservation equations ... More
Charmed-strange Meson Spectrum: Old and New ProblemsFeb 12 2015The LHCb Collaboration has recently reported the observation for the first time of a spin-$3$ resonance in the heavy quark sector. They have shown that the $\bar{D}^{0}K^{-}$ structure seen in the $B_{s}^{0}\to \bar{D}^{0}K^{-}\pi^{+}$ reaction and with ... More
The role of spin-flipping terms in hadronic transitions of $Υ(4S)$Jul 06 2015Sep 26 2015Recent experimental data on the $\Upsilon(4S)\to\Upsilon(1S)\eta$ and $\Upsilon(4S)\to h_{b}(1P)\eta$ processes seem to contradict the naive expectation that hadronic transitions with spin-flipping terms should be suppressed with respect those without ... More
Reconstructing an economic space from a market metricNov 06 2002Using a metric related to the returns correlation, a method is proposed to reconstruct an economic space from the market data. A reduced subspace, associated to the systematic structure of the market, is identified and its dimension related to the number ... More
Edge modes and non local conductance in graphene superlatticesJul 04 2017Oct 25 2017We study the existence of edge modes in gapped Moir\'e superlattices in graphene monolayer ribbons. We find that the superlattice bands acquire finite Chern numbers, which lead to a Valley Hall Effect. The presence of dispersive edge modes is confirmed ... More
Forces on Solitons in Finite, Nonlinear, Planar WaveguidesJan 16 2013The forces acting on and the energies of solitons governed by the nonlinear Schr\"odinger equation in finite, planar waveguides with periodic and with homogeneous Dirichlet, Neumann and Robin boundary conditions are determined by means of a quantum analogy. ... More
Effective Action for Hard Thermal Loops in Gravitational FieldsMar 09 2016We examine, through a Boltzmann equation approach, the generating action of hard thermal loops in the background of gravitational fields. Using the gauge and Weyl invariance of the theory at high temperature, we derive an explicit closed-form expression ... More
On the gauge independence of the fermion pole massAug 23 2013We study the question of complete gauge independence of the fermion pole mass by choosing a general class of gauge fixing which interpolates between the covariant, the axial and the Coulomb gauges for different values of the gauge fixing parameters. We ... More
Studying low-$x$ structure function models from astrophysical tau neutrinos events: double bang, lollipop and sugardaddy topologiesMar 13 2019Despite not have been yet identified by the IceCube detector, events generated from $\nu_{\tau}$ deep inelastic neutrino scattering in ice with varied topologies, such as double cascades (often called \textit{double bangs}), \textit{lollipops} and \textit{sugardaddies}, ... More
The Design of a Mobile App for Promotion of Physical Activity and Self-Management in Prostate Cancer Survivors: Personas, Feature Ideation and Low-Fidelity PrototypingNov 03 2017Jan 18 2019Most prostate cancer survivors are confronted with disease-related and treatment-related side effects that impact their quality of life. A tool that combines specific physical activity coaching with the promotion of a healthy lifestyle and self-management ... More
Resonant photon creation in a three dimensional oscillating cavityDec 08 2000Apr 12 2001We analyze the problem of photon creation inside a perfectly conducting, rectangular, three dimensional cavity with one oscillating wall. For some particular values of the frequency of the oscillations the system is resonant. We solve the field equation ... More
Bottomonium spectrum revisitedJan 19 2016We revisit the bottomonium spectrum motivated by the recently exciting experimental progress in the observation of new bottomonium states, both conventional and unconventional. Our framework is a nonrelativistic constituent quark model which has been ... More
Molecular components in $\mathbf{D_{s0}^{\ast}(2317)}$ and $\mathbf{D_{s1}(2460)}$ mesonsSep 07 2016Different experiments have confirmed that the $D_{s0}^{\ast}(2317)$ and $D_{s1}(2460)$ mesons are very narrow states located, respectively, below the $DK$ and $D^{\ast}K$ thresholds. This is markedly in contrast with the expectations of naive quark models ... More
Holographic Description of Heavy-Quark Potentials in an Inflationary Braneworld ScenarioDec 28 2008Mar 11 2009We study heavy-quark potential in an inflationary braneworld scenario. The scenario we consider is an (Euclidean) inflating braneworld $AdS_4$ embedded in a static Euclidean $AdS_5$. Using gauge/gravity duality we obtain a confining phase depending on ... More
Effective Interactions in a Graphene Layer Induced by the Proximity to a FerromagnetJul 12 2017The proximity-induced couplings in graphene due to the vicinity of a ferromagnetic insulator are analyzed. We combine general symmetry principles and simple tight-binding descriptions to consider different orientations of the magnetization. We find that, ... More
Angular distribution of satellite galaxies from the Sloan Digital Sky Survey Data Release 4Jul 07 2006We explore the angular distribution of two samples of satellite galaxies orbiting isolated hosts extracted from the Sloan Digital Sky Survey Data Release 4. We find a clear alignment of the satellites along the major axis of their hosts when restricting ... More
Not all resonances are new XYZ statesAug 03 2016Within a coupled-channel quark model framework, we study the four $J/\psi\phi$ structures called $X(4140)$, $X(4274)$, $X(4500)$ and $X(4700)$ and observed, each with a significance over $5$ standard deviations, by the LHCb Collaboration in the $B^{+}\to ... More
Overdispersed Black-Box Variational InferenceMar 03 2016We introduce overdispersed black-box variational inference, a method to reduce the variance of the Monte Carlo estimator of the gradient in black-box variational inference. Instead of taking samples from the variational distribution, we use importance ... More
Dimensional Reduction, Hard Thermal Loops and the Renormalization GroupMay 17 2004We study the realization of dimensional reduction and the validity of the hard thermal loop expansion for lambda phi^4 theory at finite temperature, using an environmentally friendly finite-temperature renormalization group with a fiducial temperature ... More
Designing a minimalist socially aware robotic agent for the homeJun 26 2014We present a minimalist social robot that relies on long timeseries of low resolution data such as mechanical vibration, temperature, lighting, sounds and collisions. Our goal is to develop an experimental system for growing socially situated robotic ... More
Modeling gamma-ray burst observations by Fermi and MAGIC including attenuation due to diffuse background lightAug 19 2009Gamma rays from extragalactic sources are attenuated by pair-production interactions with diffuse photons of the extragalactic background light (EBL). Gamma-ray bursts (GRBs) are a source of high-redshift photons above 10 GeV, and could be therefore useful ... More
Threshold effects in P-wave bottom-strange mesonsDec 14 2016Using a nonrelativistic constituent quark model in which the degrees of freedom are quark-antiquark and meson-meson components, we have recently shown that the $D^{(\ast)}K$ thresholds play an important role in lowering the mass of the physical $D_{s0}^{\ast}(2317)$ ... More
Zeros of Orthogonal Polynomials Generated by Canonical Perturbations on Standard MeasureMay 03 2010Jun 21 2010In this contribution, the behavior of zeros of orthogonal polynomials associated with canonical linear spectral transformations of measures supported in the real line is analyzed. An electrostatic interpretation of them is given.
Machine Translation Evaluation with Neural NetworksOct 05 2017We present a framework for machine translation evaluation using neural networks in a pairwise setting, where the goal is to select the better translation from a pair of hypotheses, given the reference translation. In this framework, lexical, syntactic ... More
The Generalized Reparameterization GradientOct 07 2016Oct 14 2016The reparameterization gradient has become a widely used method to obtain Monte Carlo gradients to optimize the variational objective. However, this technique does not easily apply to commonly used distributions such as beta or gamma without further approximations, ... More
Kink stability, propagation, and length scale competition in the periodically modulated sine-Gordon equationJan 24 1994We have examined the dynamical behavior of the kink solutions of the one-dimensional sine-Gordon equation in the presence of a spatially periodic parametric perturbation. Our study clarifies and extends the currently available knowledge on this and related ... More
Fixed point indices of planar continuous mapsMay 27 2016We characterize the sequences of fixed point indices $\{i(f^n, p)\}_{n\ge 1}$ of fixed points that are isolated as an invariant set and continuous maps in the plane. In particular, we prove that the sequence is periodic and $i(f^n, p) \le 1$ for every ... More
Molecular components in P-wave charmed-strange mesonsMar 22 2016Jul 23 2016Results obtained by various experiments show that the $D_{s0}^{\ast}(2317)$ and $D_{s1}(2460)$ mesons are very narrow states located below the $DK$ and $D^{\ast}K$ thresholds, respectively. This is markedly in contrast with the expectations of naive quark ... More
Pulsations of rapidly rotating stars with compositional discontinuitiesOct 11 2013Recent observations of rapidly rotating stars have revealed the presence of regular patterns in their pulsation spectra. This has raised the question as to their physical origin, and in particular, whether they can be explained by an asymptotic frequency ... More
Drawing dynamical and parameter planes of iterative families and methodsJul 25 2013In this paper the complex dynamical analysis of the parametric fourth-order Kim's iterative family is made on quadratic polynomials, showing the Matlab codes generated to draw the fractal images necessary to complete the study. The parameter spaces associated ... More
Recovering the nonlinear density field from the galaxy distribution with a Poisson-Lognormal filterNov 07 2009We present a general expression for a lognormal filter given an arbitrary nonlinear galaxy bias. We derive this filter as the maximum a posteriori solution assuming a lognormal prior distribution for the matter field with a given mean field and modeling ... More
Canonical description of the new LHCb resonancesAug 03 2016Oct 25 2016The LHCb Collaboration has recently observed four $J/\psi\phi$ structures called $X(4140)$, $X(4274)$, $X(4500)$ and $X(4700)$ in the $B^{+}\to J/\psi\phi K^{+}$ decays. We study them herein using a nonrelativistic constituent quark model in which the ... More
The Generalized Reparameterization GradientOct 07 2016Oct 19 2016The reparameterization gradient has become a widely used method to obtain Monte Carlo gradients to optimize the variational objective. However, this technique does not easily apply to commonly used distributions such as beta or gamma without further approximations, ... More
Noncommutative field gas driven inflationJan 05 2008Mar 14 2008We investigate early time inflationary scenarios in an Universe filled with a dilute noncommutative bosonic gas at high temperature. A noncommutative bosonic gas is a gas composed of bosonic scalar field with noncommutative field space on a commutative ... More
Majorana Zero-Modes in a Two-Dimensional $p$-Wave SuperconductorFeb 03 2017Jun 14 2017We analyze the formation of Majorana zero-modes at the edge of a two-dimensional topological superconductor. In particular, we study a time-reversal-invariant triplet phase that is likely to exist in doped Bi$_2$Se$_3$. Upon the introduction of an in-plane ... More
Unquenching the quark model in a non-perturbative schemeJan 08 2019In recent years, the discovery in quarkonium spectrum of several states not predicted by the naive quark model has awakened a lot of interest. A possible description of such states requires the enlargement of the quark model by introducing quark-antiquark ... More
The $Z_c$ structures in a coupled-channels modelAug 02 2018Jan 07 2019The $Z_{c}(3900)^\pm/Z_c(3885)^\pm$ and $Z_{c}(4020)^\pm$ are two charmonium-like structures discovered in the $\pi J/\psi$ and $D^\ast\bar D^{(\ast)}+h.c.$ invariant mass spectra. Their nature is puzzling due to their charge, which forces its minimal ... More
Charmonium resonances in the 3.9 GeV/$c^2$ energy region and the $X(3915)/X(3930)$ puzzleJun 08 2017Sep 05 2017An interesting controversy has emerged challenging the widely accepted nature of the $X(3915)$ and the $X(3930)$ resonances, which had initially been assigned to the $\chi_{c0}(2P)$ and $\chi_{c2}(2P)$ $c\bar c$ states, respectively. To unveil their inner ... More
PVM-Distributed Implementation of the Radiance CodeFeb 22 2008The Parallel Virtual Machine (PVM) tool has been used for a distributed implementation of Greg Ward's Radiance code. In order to generate exactly the same primary rays with both the sequential and the parallel codes, the quincunx sampling technique used ... More
Quantum electromagnetic field in a three dimensional oscillating cavityMay 16 2002We compute the photon creation inside a perfectly conducting, three dimensional oscillating cavity, taking the polarization of the electromagnetic field into account. As the boundary conditions for this field are both of Dirichlet and (generalized) Neumann ... More
Comparative kinetics of the snowball respect to other dynamical objectsOct 01 2003Oct 01 2003We examine the kinetics of a snowball that is gaining mass while is rolling downhill. This dynamical system combines rotational effects with effects involving the variation of mass. In order to understand the consequences of both effects we compare its ... More
Null paths on a toroidal topological black hole in conformalWeyl gravityAug 13 2018The motion of massless particles on the background of a toroidal topological black hole is analyzed in the context of conformal Weyl gravity. Null geodesics, in terms of the Jacobi elliptic functions, are found analytically. In addition, the Sagnac effect ... More
Neutral and Stable Equilibria of Genetic Systems and The Hardy-Weinberg Principle: Limitations of the Chi-Square Test and Advantages of Auto-Correlation Functions of Allele FrequenciesAug 13 2012Aug 14 2012Since the foundations of Population Genetics the notion of genetic equilibrium (in close analogy to Classical Mechanics) has been associated to the Hardy-Weinberg (HW) Principle and the identification of equilibrium is currently assumed by stating that ... More
Indices of the iterates of $R^3$-homeomorphisms at Lyapunov stable fixed pointsApr 18 2007Given any positive sequence (\{c_n\}_{n \in {\Bbb N}}), we construct orientation preserving homeomorphisms (f:{\Bbb R}^3 \to {\Bbb R}^3) such that (Fix(f)=Per(f)=\{0\}), (0) is Lyapunov stable and (\limsup \frac{|i(f^m, 0)|}{c_m}= \infty). We will use ... More
The zero-inflated promotion cure rate regression model applied to fraud propensity in bank loan applicationsOct 01 2015In this paper we extend the promotion cure rate model proposed by Chen et al (1999), by incorporating excess of zeros in the modelling. Despite allowing to relate the covariates to the fraction of cure, the current approach, which is based on a biological ... More
The zero-inflated cure rate regression model: Applications to fraud detection in bank loan portfoliosSep 17 2015Sep 19 2015In this paper, we introduce a methodology based on the zero-inflated cure rate model to detect fraudsters in bank loan applications. In fact, our approach enables us to accommodate three different types of loan applicants, i.e., fraudsters, those who ... More
Threshold effects in hadron spectrum: a new spectroscopy?Nov 15 2017The exploration of energies above the open-flavor threshold in the meson spectra has led to the appearance of unexpected states difficult to accommodate in the naive picture of a bound state of a quark and an antiquark. Many of such states are located ... More
Cornell Model Calibration with NRQCD at N$^3$LONov 27 2018The typical binding energy of heavy hadron spectroscopy makes the system accessible to perturbative calculations in terms of non-relativistic QCD. Within NRQCD the predictions of heavy quarkonium energy levels rely on the accurate description of the static ... More
Calibrating the Naïve Cornell Model with NRQCDNov 05 2018Building on results from a previous study on heavy meson spectroscopy, we calibrate the Cornell model employing NRQCD predictions for the lowest-lying bottomonium states up to N$^3$LO, in which the bottom mass is varied within a wide range. We find that ... More
Exponential Family EmbeddingsAug 02 2016Word embeddings are a powerful approach for capturing semantic similarity among terms in a vocabulary. In this paper, we develop exponential family embeddings, a class of methods that extends the idea of word embeddings to other types of high-dimensional ... More
Exponential Family EmbeddingsAug 02 2016Nov 21 2016Word embeddings are a powerful approach for capturing semantic similarity among terms in a vocabulary. In this paper, we develop exponential family embeddings, a class of methods that extends the idea of word embeddings to other types of high-dimensional ... More
Massive Stars in the SGR 1806-20 ClusterJan 25 2005Jan 30 2005We report the discovery of additional hot and massive stars in the cluster surrounding the soft gamma repeater SGR 1806-20, based upon UKIRT and Keck near-infrared spectroscopy. Of the newly identified stars, three are Wolf-Rayet stars of types WC8, WN6, ... More
Characterization of complex networks: A survey of measurementsMay 07 2005Aug 16 2006Each complex network (or class of networks) presents specific topological features which characterize its connectivity and highly influence the dynamics of processes executed on the network. The analysis, discrimination, and synthesis of complex networks ... More
Chain motifs: The tails and handles of complex networksJun 15 2007Oct 26 2007Great part of the interest in complex networks has been motivated by the presence of structured, frequently non-uniform, connectivity. Because diverse connectivity patterns tend to result in distinct network dynamics, and also because they provide the ... More
Border trees of complex networksJun 22 2007The comprehensive characterization of the structure of complex networks is essential to understand the dynamical processes which guide their evolution. The discovery of the scale-free distribution and the small world property of real networks were fundamental ... More
Multi-Threaded Dense Linear Algebra Libraries for Low-Power Asymmetric Multicore ProcessorsNov 06 2015Dense linear algebra libraries, such as BLAS and LAPACK, provide a relevant collection of numerical tools for many scientific and engineering applications. While there exist high performance implementations of the BLAS (and LAPACK) functionality for many ... More
A Model for the Dynamics of Gene NetworksMay 14 2013May 19 2013In this work we propose a model for gene expression based on the theory of random dynamical systems (RDS) and show that it has a "modularity property" in the following sense: given any collection of genes that are linked in a transcriptional network, ... More
Dynamics and eigenvalues in dimension zeroJul 20 2018Nov 21 2018Let $X$ be a compact, metric and totally disconnected space and let $f:X\to X$ be a continuos map. We relate the eigenvalues of $f_{*}:\check{H}_{0}(X;\mathbb{C})\to\check{H}_{0}(X;\mathbb{C})$ to dynamical properties of $f$, roughly showing that if the ... More
Modulation invariant bilinear T(1) theoremOct 04 2007We prove a T(1) theorem for bilinear singular integral operators (trilinear forms) with a one-dimensional modulation symmetry.
Finite temperature dynamics of vortices in the two dimensional anisotropic Heisenberg modelOct 01 1998We study the effects of finite temperature on the dynamics of non-planar vortices in the classical, two-dimensional anisotropic Heisenberg model with XY- or easy-plane symmetry. To this end, we analyze a generalized Landau-Lifshitz equation including ... More
Optical polarization and near IR photometry of the proto-planetary nebula Hen 3-1475Dec 19 2002We present BVRI CCD aperture polarization and near-infrared photometry of the proto-planetary nebula Hen 3-1475. Its intrinsic polarization is high and shows a strong spectral dependence. The position angles in all bands are perpendicular to the axis ... More
Exponential equilibration by slow cooling in the planar random-anisotropy magnet: experiments and simulationsJul 22 2008Neutron measurements of the equilibration of the staggered magnetization in DyAs(0.35)V(0.65)O4 are compared with Monte Carlo simulations of spin dynamics in a planar random-anisotropy magnet. The simulation results are in agreement with striking observed ... More
Deep learning for plasma tomography using the bolometer system at JETJan 02 2017Deep learning is having a profound impact in many fields, especially those that involve some form of image processing. Deep neural networks excel in turning an input image into a set of high-level features. On the other hand, tomography deals with the ... More
Bayesian nonparametric comorbidity analysis of psychiatric disordersJan 29 2014The analysis of comorbidity is an open and complex research field in the branch of psychiatry, where clinical experience and several studies suggest that the relation among the psychiatric disorders may have etiological and treatment implications. In ... More
About the homological discrete Conley index of isolated invariant acyclic continuaFeb 05 2013This article includes an almost self-contained exposition on the discrete Conley index and its duality. We work with a local homeomorphism of $\mathds{R}^d$ and an invariant and isolated acyclic continuum, such as a cellular set or a fixed point. In this ... More
Counting states and the Hadron Resonance Gas: Does X(3872) count?Jul 06 2017Apr 30 2018We analyze how the renowned X(3872), a weakly bound state right below the $D \bar D^*$ threshold, should effectively be included in a hadronic representation of the QCD partition function. This can be decided by analyzing the $D \bar D^*$ scattering phase-shifts ... More
Ground State of the Hydrogen Atom via Dirac Equation in a Minimal Length ScenarioAug 15 2013In this work we calculate the correction to the ground state energy of the hydrogen atom due to contributions arising from the presence of a minimal length. The minimal length scenario is introduced by means of modifying the Dirac equation through a deformed ... More
Hertz potentials approach to the dynamical Casimir effect in cylindrical cavities of arbitrary sectionNov 15 2004We study the creation of photons in resonant cylindrical cavities with time dependent length. The physical degrees of freedom of the electromagnetic field are described using Hertz potentials. We describe the general formalism for cavities with arbitrary ... More
Casimir force between eccentric cylindersJun 09 2004We consider the Casimir interaction between a cylinder and a hollow cylinder, both conducting, with parallel axis and slightly different radii. The Casimir force, which vanishes in the coaxial situation, is evaluated for both small and large eccentricities ... More
Model for resonant photon creation in a cavity with time dependent conductivityApr 23 2004Jul 14 2004In an electromagnetic cavity, photons can be created from the vacuum state by changing the cavity's properties with time. Using a simple model based on a massless scalar field, we analyze resonant photon creation induced by the time-dependent conductivity ... More
Towards deductive verification of MPI programs against session typesDec 10 2013The Message Passing Interface (MPI) is the de facto standard message-passing infrastructure for developing parallel applications. Two decades after the first version of the library specification, MPI-based applications are nowadays routinely deployed ... More
Model Criticism for Bayesian Causal InferenceOct 27 2016The goal of causal inference is to understand the outcome of alternative courses of action. However, all causal inference requires assumptions. Such assumptions can be more influential than in typical tasks for probabilistic modeling, and testing those ... More
Rejection Sampling Variational InferenceOct 18 2016Variational inference using the reparameterization trick has enabled large-scale approximate Bayesian inference in complex probabilistic models, leveraging stochastic optimization to sidestep intractable expectations. The reparameterization trick is applicable ... More
Towards a precision measurement of the Casimir force in a cylinder-plane geometryNov 02 2005We report on a proposal aimed at measuring the Casimir force in a cylinder-plane configuration. The Casimir force is evaluated including corrections due to finite parallelism, conductivity, and temperature. The range of validity of the proximity force ... More
Hopf bifurcation with zero frequency and imperfect SO(2) symmetryJun 08 2012Rotating waves are periodic solutions in SO(2) equivariant dynamical systems. Their precession frequency changes with parameters and it may change sign, passing through zero. When this happens, the dynamical system is very sensitive to imperfections that ... More
Uniqueness of dynamical zeta functions and symmetric productsMay 27 2016A characterization of dynamically defined zeta functions is presented. It comprises a list of axioms, natural extension of the one which characterizes topological degree, and a uniqueness theorem. Lefschetz zeta function is the main (and proved unique) ... More