Results for "J. Alves"

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Markov structures and decay of correlations for non-uniformly expanding dynamical systemsMay 17 2002We consider non-uniformly expanding maps on compact Riemannian manifolds of arbitrary dimension, possibly having discontinuities and/or critical sets, and show that under some general conditions they admit an induced Markov tower structure for which the ... More
Molecular clouds have power-law probability distribution functionsFeb 12 2015In this Letter we investigate the shape of the probability distribution of column densities (PDF) in molecular clouds. Through the use of low-noise, extinction-calibrated \textit{Herschel}/\textit{Planck} emission data for eight molecular clouds, we demonstrate ... More
Dynamics of the 3/1 planetary mean-motion resonance. An application to the HD60532 b-c planetary systemNov 27 2015In this paper, we use a semi-analytical approach to analyze the global structure of the phase space of the planar planetary 3/1 mean-motion resonance, in cases where the outer planet is more massive than its inner companion. We show that the resonant ... More
Herschel-Planck dust optical-depth and column-density maps: I. Method description and results for OrionMar 31 2014Apr 02 2014We present high-resolution, high dynamic range column-density and color-temperature maps of the Orion complex using a combination of Planck dust-emission maps, Herschel dust-emission maps, and 2MASS NIR dust-extinction maps. The column-density maps combine ... More
Existence result for a class of quasilinear elliptic equations with (p-q)-laplacian and vanishing potentialsAug 26 2015The main purpose of this paper is to establish the existence of positive solutions to a class of quasilinear elliptic equations involving the (p-q)-Laplacian operator. We consider a nonlinearity that can be subcritical at infinity and supercritical at ... More
Morphological transition between diffusion-limited and ballistic aggregation growth patternsApr 20 2005Mar 23 2006In this work, the transition between diffusion-limited and ballistic aggregation models was revisited using a model in which biased random walks simulate the particle trajectories. The bias is controlled by a parameter $\lambda$, which assumes the value ... More
Fisher matrix forecasts for astrophysical tests of the stability of the fine-structure constantApr 27 2017We use Fisher Matrix analysis techniques to forecast the cosmological impact of astrophysical tests of the stability of the fine-structure constant to be carried out by the forthcoming ESPRESSO spectrograph at the VLT (due for commissioning in late 2017), ... More
A note on quadrangular embedding of Abelian Cayley GraphsApr 01 2010Jan 04 2016The genus graphs have been studied by many authors, but just a few results concerning in special cases: Planar, Toroidal, Complete, Bipartite and Cartesian Product of Bipartite. We present here a derive general lower bound for the genus of a abelian Cayley ... More
Data-driven Predictive Energy Optimization in a Wastewater Pumping StationFeb 09 2019The wastewater management sector is being pushed to optimize processes in order to reduce energy consumption without compromising its quality standards. Energy costs can represent a significant share of the global operational costs (between 50\% and 60\%) ... More
Spontaneous symmetry breaking in amnestically induced persistenceAug 22 2007Sep 11 2007We investigate a recently proposed non-Markovian random walk model characterized by loss of memories of the recent past and amnestically induced persistence. We report numerical and analytical results showing the complete phase diagram, consisting of ... More
Size distribution of circumstellar disks in the Trapezium clusterJun 24 2005In this paper we present results on the size distribution of circumstellar disks in the Trapezium cluster as measured from HST/WFPC2 data. Direct diameter measurements of a sample of 135 bright proplyds and 14 silhouettes disks suggest that there is a ... More
Global persistence exponent of the two-dimensional Blume-Capel modelFeb 09 2003The global persistence exponent $\theta_g$ is calculated for the two-dimensional Blume-Capel model following a quench to the critical point from both disordered states and such with small initial magnetizations. Estimates are obtained for the nonequilibrium ... More
Time-dependent Monte Carlo simulations of the critical and Lifshitz points of the ANNNI modelDec 18 2016In this work, we study the critical behavior of second order points and specifically of the Lifshitz point (LP) of a three-dimensional Ising model with axial competing interactions (ANNNI model), using time-dependent Monte Carlo simulations. First of ... More
Mixed initial conditions to estimate the dynamic critical exponent in short-time Monte Carlo simulationNov 15 2001We explore the initial conditions in short-time critical dynamics to propose a new method to evaluate the dynamic exponent z. Estimates are obtained with high precision for 2D Ising model and 2D Potts model for three and four states by performing heat-bath ... More
Finite Blocklength Communications in Smart Grids for Dynamic Spectrum Access and Locally Licensed ScenariosMay 24 2018This work focuses on the performance analysis of short blocklength communication with application in smart grids. We use stochastic geometry to compute in closed form the success probability of a typical message transmission as a function of its size ... More
The tricky line of sight towards Cygnus-X: The [DB2001] CL05 embedded cluster as a pilot caseMar 04 2019The nearest massive star-forming complex, Cygnus-X, is widely used as a laboratory for star cluster formation and feedback processes, under the implicit assumption that all its components are located roughly at the same distance. We present a multi-wavelength ... More
Indirect and monojet constraints on scalar leptoquarksDec 20 2018We obtain constraints on first- and second-generation scalar leptoquarks using the available data on dilepton (Drell-Yan) and monojet searches at the CERN Large Hadron Collider. Assuming that the leptoquark interactions respect the Standard Model gauge ... More
Orion Revisited - I. The massive cluster in front of the Orion Nebula ClusterSep 17 2012Sep 26 2012The aim of this work is to characterize the stellar population between Earth and the Orion A molecular cloud where the well known star formation benchmark Orion Nebula Cluster (ONC) is embedded. We use the denser regions the Orion A cloud to block optical ... More
Throughput Maximization in Multi-Hop Wireless Networks under Secrecy ConstraintApr 16 2015Dec 17 2015This paper analyzes the throughput of industrial communication networks under a secrecy constraint. The proposed scenario is composed by sensors that measure some relevant information of the plant that is first processed by aggregator node and then sent ... More
Effects of Relay Selection Strategies on the Spectral Efficiency of Wireless Systems with Half- and Full-duplex NodesJul 14 2015Jan 29 2017This work proposes an analytical framework to study how relay selection strategies perform in half- and full-duplex deployments by combining renewal theory and stochastic geometry. Specifically, we assume that the network nodes -- operating in either ... More
Smoke in the Pipe Nebula: dust emission and grain growth in the starless core FeSt 1-457May 22 2015(abridged) Methods: We derive maps of submillimeter dust optical depth and effective dust temperature from Herschel data that were calibrated against Planck. After calibration, we then fit a modified blackbody to the long-wavelength Herschel data, using ... More
Universality and scaling study of the critical behavior of the two-dimensional Blume-Capel model in short-time dynamicsApr 16 2002In this paper we study the short-time behavior of the Blume-Capel model at the tricritical point as well as along the second order critical line. Dynamic and static exponents are estimated by exploring scaling relations for the magnetization and its moments ... More
Deep Near-Infrared Survey of the Pipe Nebula II: Data, Methods, and Dust Extinction MapsNov 05 2010We present a new set of high resolution dust extinction maps of the nearby and essentially starless Pipe Nebula molecular cloud. The maps were constructed from a concerted deep near-infrared imaging survey with the ESO-VLT, ESO-NTT, CAHA 3.5m telescopes, ... More
Secondary flows of viscoelastic fluids in serpentine microchannelsOct 29 2018Feb 12 2019Secondary flows are ubiquitous in channel flows, where small velocity components perpendicular to the main velocity appear due to the complexity of the channel geometry and/or that of the flow itself such as from inertial or non-Newtonian effects, etc. ... More
Uncovering the kiloparsec-scale stellar ring of NGC5128Jun 19 2009We reveal the stellar light emerging from the kiloparsec-scale, ring-like structure of the NGC5128 (Centaurus A) galaxy in unprecedented detail. We use arcsecond-scale resolution near infrared images to create a "dust-free" view of the central region ... More
Fundamental physics constraints from testing the stability of the fine-structure constant with the ELTsFeb 07 2019The increased collecting area of the ELTs will bring fainter high-z targets within the reach of high-resolution ultra-stable spectrographs, thus enabling a new generation of precision consistency tests, including tests of the stability of nature's fundamental ... More
Star Formation in the W49A Molecular Cloud: Birth of a Massive Star ClusterAug 31 2004The W49A star-forming region is embedded in a 10^6 solar mass molecular cloud, one of the most massive in our Galaxy. It has been long known as one of the most luminous radio HII regions, containing 30-40 compact and ultracompact HII regions and several ... More
Massive Star Formation in the W49 Giant Molecular Cloud: Implications for the Formation of Massive Star ClustersSep 16 2004We present results from JHKs imaging of the densest region of the W49 molecular cloud. In a recent paper (Alves & Homeier 2003), we reported the detection of (previously unknown) massive stellar clusters in the well-known giant radio HII region W49A, ... More
Error threshold in the evolution of diploid organismsDec 09 1996The effects of error propagation in the reproduction of diploid organisms are studied within the populational genetics framework of the quasispecies model. The dependence of the error threshold on the dominance parameter is fully investigated. In particular, ... More
Micromechanical study of the dilatational response of porous solids with pressure-insensitive matrix displaying tension-compression asymmetryMar 17 2014Nov 26 2014In this paper, the dilatational response of porous solids with pressure-insensitive matrix displaying strength differential (SD) effects is investigated. To this end, micromechanical finite-element analyses of three-dimensional unit cells are carried ... More
Decoupling inequalities and supercritical percolation for the vacant set of random walk loop soupAug 03 2018It has been recently understood (arXiv:1212.2885, arXiv:1310.4764, arXiv:1410.0605) that for a general class of percolation models on $\mathbb{Z}^d$ satisfying suitable decoupling inequalities, which includes i.a.\ Bernoulli percolation, random interlacements ... More
Error threshold in finite populationsSep 23 1997Mar 31 1998A simple analytical framework to study the molecular quasispecies evolution of finite populations is proposed, in which the population is assumed to be a random combination of the constiyuent molecules in each generation,i.e., linkage disequilibrium at ... More
A new Level-set based Protocol for Accurate Bone Segmentation from CT ImagingMay 12 2015In this work it is proposed a medical image segmentation pipeline for accurate bone segmentation from CT imaging. It is a two-step methodology, with a pre-segmentation step and a segmentation refinement step. First, the user performs a rough segmenting ... More
On the trace anomaly and the energy-momentum conservation of quantum fields at D=2 in classical curved backgroundsDec 09 2003We study the conformal symmetry and the energy-momentum conservation of scalar field interacting with a curved background at D=2. We avoid to incorporate the metric determinant into the measure of the scalar field to explain the conformal anomaly and ... More
Legendrian contact homology and topological entropySep 12 2014Apr 23 2016In this paper we study the growth rate of a version of Legendrian contact homology, which we call strip Legendrian contact homology, in 3-dimensional contact manifolds and its relation to the topological entropy of Reeb flows. We show that: if for a pair ... More
Strong statistical stability of non-uniformly expanding mapsNov 25 2003We consider families of transformations in multidimensional Riemannian manifolds with non-uniformly expanding behavior. We give sufficient conditions for the continuous variation (in the $L^1$-norm) of the densities of absolutely continuous (with respect ... More
Machine Learning simulates Agent-Based ModelDec 12 2017Running agent-based models (ABMs) is a burdensome computational task, specially so when considering the flexibility ABMs intrinsically provide. This paper uses a bundle of model configuration parameters along with obtained results from a validated ABM ... More
Extended stellar systems in the solar neighborhood - I. The tidal tails of the HyadesNov 12 2018Dec 14 2018We report the discovery of two well-defined tidal tails emerging from the Hyades star cluster. The tails were detected in Gaia DR2 data by selecting cluster members in the three-dimensional galactocentric cylindrical velocity space. The robustness of ... More
Dirac-Surface-State-Dominated Spin to Charge Current Conversion in the Topological Insulator $(Bi_{0.22}Sb_{0.78})_2Te_3$ Films at Room TemperatureOct 17 2017We report the spin to charge current conversation in an intrinsic topological insulator (TI) $(Bi_{0.22}Sb_{0.78})_2Te_3$ film at room temperature. The spin currents are generated in a thin layer of permalloy (Py) by two different processes, spin pumping ... More
Near infrared imaging of NGC2316Nov 20 2003In the present paper we present JHK photometric results of the young embedded cluster NGC 2316. We construct the cluster radial profile from which we determine a radius of 0.63 pc. We find 189 $\pm$ 29 cluster members in an extinction limited sub-sample ... More
The Li-age correlation: the Sun is unusually Li deficient for its ageMar 07 2019The present work aims to examine in detail the depletion of lithium in solar twins to better constrain stellar evolution models and investigate its possible connection with exoplanets. We employ spectral synthesis in the region of the asymmetric 6707.75 ... More
Amplification and generation of ultra-intense twisted laser pulses via stimulated Raman scatteringMar 09 2016Twisted Laguerre-Gaussian lasers, with orbital angular momentum and characterised by doughnut shaped intensity profiles, provide a transformative set of tools and research directions in a growing range of fields and applications, from super-resolution ... More
High orbital angular momentum harmonic generationNov 10 2016We identify and explore a high orbital angular momentum (OAM) harmonics generation and amplification mechanism that manipulates the OAM independently of any other laser property, by preserving the initial laser wavelength, through stimulated Raman backscattering ... More
Instabilities and propagation of neutrino magnetohydrodynamic waves in arbitrary directionDec 14 2017In a previous work [16], a new model was introduced, taking into account the role of the Fermi weak force due to neutrinos coupled to magnetohydrodynamic plasmas. The resulting neutrino-magnetohydrodynamics was investigated in a particular geometry associated ... More
On the Complexity of Quantum LanguagesApr 12 2004The standard inputs given to a quantum machine are classical binary strings. In this view, any quantum complexity class is a collection of subsets of $\{0,1\}^{*}$. However, a quantum machine can also accept quantum states as its input. T. Yamakami has ... More
Hyperbolic times: frequency vs. integrabilityNov 25 2003We consider dynamical systems on compact manifolds, which are local diffeomorphisms outside an exceptional set (a compact submanifold). We are interested in analyzing the relation between the integrability (with respect to Lebesgue measure) of the first ... More
Traces in monoidal derivators, and homotopy colimitsMar 01 2013Jul 16 2014A variant of the trace in a monoidal category is given in the setting of closed monoidal derivators, which is applicable to endomorphisms of fiberwise dualizable objects. Functoriality of this trace is established. As an application, an explicit formula ... More
Mass spectrometry based protein identification with accurate statistical significance assignmentJul 24 2014Motivation: Assigning statistical significance accurately has become increasingly important as meta data of many types, often assembled in hierarchies, are constructed and combined for further biological analyses. Statistical inaccuracy of meta data at ... More
Combining independent, arbitrarily weighted P-values: a new solution to an old problem using a novel expansion with controllable accuracyNov 30 2010Good's formula and Fisher's method are frequently used for combining independent P-values. Interestingly, the equivalent of Good's formula already emerged in 1910 and mathematical expressions relevant to even more general situations have been repeatedly ... More
The mass function of dense molecular cores and the origin of the IMFDec 05 2006Context: Stars form in the cold dense cores of interstellar molecular clouds and the detailed knowledge of the spectrum of masses of such cores is clearly a key for the understanding of the origin of the IMF. To date, observations have presented somewhat ... More
Correlation Between Gas and Dust in Molecular Clouds: L977Sep 03 1998We report observations of the J =(1--0) C18O molecular emission line toward the L977 molecular cloud. To study the correlation between C18O emission and dust extinction we constructed a Gaussian smoothed map of the infrared extinction measured by Alves ... More
The Bones of the Milky WayJul 31 2014The very long and thin infrared dark cloud "Nessie" is even longer than had been previously claimed, and an analysis of its Galactic location suggests that it lies directly in the Milky Way's mid-plane, tracing out a highly elongated bone-like feature ... More
The Formation and Early Evolution of Young Massive ClustersJan 16 2014We review the formation and early evolution of the most massive and dense young stellar clusters, focusing on the role they can play in our understanding of star and planet formation as a whole. Young massive cluster (YMC) progenitor clouds in the Galactic ... More
Current and future constraints on extended Bekenstein-type models for a varying fine-structure constantJan 24 2018There is a growing interest in astrophysical tests of the stability of dimensionless fundamental couplings, such as the fine-structure constant $\alpha$, as an optimal probe of new physics. The imminent arrival of the ESPRESSO spectrograph will soon enable ... More
Strong stochastic stability for non-uniformly expanding mapsFeb 26 2010We consider random perturbations of discrete-time dynamical systems. We give sufficient conditions for the stochastic stability of certain classes of maps, in a strong sense. This improves the main result in J. F. Alves, V. Araujo, Random perturbations ... More
Fibers in the NGC1333 proto-clusterMar 21 2017Are the initial conditions for clustered star formation the same as for non-clustered star formation? To investigate the initial gas properties in young proto-clusters we carried out a comprehensive and high-sensitivity study of the internal structure, ... More
A new method to unveil embedded stellar clustersJul 26 2017In this paper we present a novel method to identify and characterize stellar clusters deeply embedded in a dark molecular cloud. The method is based on measuring stellar surface density in wide-field infrared images using star counting techniques. It ... More
Gibbs-Markov structures and limit laws for partially hyperbolic attractors with mostly expanding central directionAug 31 2009We consider a partially hyperbolic set $K$ on a Riemannian manifold $M$ whose tangent space splits as $T_K M=E^{cu}\oplus E^{s}$, for which the centre-unstable direction $E^{cu}$ expands non-uniformly on some local unstable disk. We show that under these ... More
Gibbs-Markov-Young structures with (stretched) exponential tail for partially hyperbolic attractorsJan 30 2013Dec 17 2015We study partially hyperbolic sets $K$ on a Riemannian manifold $M$ whose tangent space splits as $T_K M=E^{cu}\oplus E^{s}$, for which the center-unstable direction $E^{cu}$ is non-uniformly expanding on some local unstable disk. We prove that the (stretched) ... More
Statistical stability and limit laws for Rovella mapsMay 25 2012We consider the family of one-dimensional maps arising from the contracting Lorenz attractors studied by Rovella. Benedicks-Carleson techniques were used by Rovella to prove that there is a one-parameter family of maps whose derivatives along their critical ... More
tt-geometry of Tate motives over algebraically closed fieldsAug 02 2017Oct 23 2017We study Tate motives with integral coefficients through the lens of tensor triangular geometry. For some base fields, including the field of algebraic numbers and the algebraic closure of a finite field, we arrive at a complete description of the tensor ... More
Numerical simulation of electrically-driven flows using OpenFOAMFeb 08 2018Sep 04 2018In this work, we study the implementation of electrically-driven flow (EDF) models in the finite-volume framework of $\text{OpenFOAM}^\circledR$. The Poisson-Nernst-Planck model is used for the transport of charged species and it is coupled to the Navier-Stokes ... More
The Predictive Power of R0 in an Epidemic Probabilistic SystemFeb 12 2003An important issue in theoretical epidemiology is the epidemic threshold phenomenon, which specify the conditions for an epidemic to grow or die out. In standard (mean-field-like) compartmental models the concept of the basic reproductive number, R0, ... More
Fitting density models to observational data - The local Schmidt law in molecular cloudsOct 14 2013Oct 15 2013We consider the general problem of fitting a parametric density model to discrete observations, taken to follow a non-homogeneous Poisson point process. This class of models is very common, and can be used to describe many astrophysical processes, including ... More
A novel computational modelling to describe the anisotropic, remodelling and reorientation behaviour of collagen fibrres in articular cartilageJan 20 2016In articular cartilage the orientation of collagen fibres is not uniform, varying mostly with the depth on the tissue. Besides, the biomechanical response of each layer of the articular cartilage differs from the neighbouring ones, evolving through thickness ... More
Hipparcos distances of Ophiuchus and Lupus cloud complexesJan 22 2008Jan 24 2008We combine extinction maps from the Two Micron All Sky Survey (2MASS) with Hipparcos and Tycho parallaxes to obtain reliable and high-precision estimates of the distance to the Ophiuchus and Lupus dark complexes. Our analysis, based on a rigorous maximum-likelihood ... More
Storage Management in Modern Electricity Power GridsDec 02 2016This letter introduces a method to manage energy storage in electricity grids. Starting from the stochastic characterization of electricity generation and demand, we propose an equation that relates the storage level for every time-step as a function ... More
Centro-affine Codimension 2 Immersions: Umbilical and Inflection PointsNov 18 2018Nov 29 2018In this paper we consider centroaffine codimension 2 immersions with an eq\"uiaffine transversal vector field. We prove that asymptotic lines, resp. inflection points, of an immersion correspond to principal lines, resp. umbilical points, of its dual. ... More
Larson's third law and the universality of molecular cloud structureAug 25 2010Larson (1981) first noted a scaling relation between masses and sizes in molecular clouds that implies that these objects have approximately constant column densities. This original claim, based upon millimeter observations of carbon monoxide lines, has ... More
2MASS wide field extinction maps: II. The Ophiuchus and the Lupus cloud complexeSep 22 2008We present an extinction map of a ~1,700 deg sq region that encloses the Ophiuchus, the Lupus, and the Pipe dark complexes using 42 million stars from the Two Micron All Sky Survey (2MASS) point source catalog. The use of a robust and optimal near-infrared ... More
Transitions in a Probabilistic Interface Growth ModelApr 04 2011May 08 2011We study a generalization of the Wolf-Villain (WV) interface growth model based on a probabilistic growth rule. In the WV model, particles are randomly deposited onto a substrate and subsequently move to a position nearby where the binding is strongest. ... More
Backward volume contraction for endomorphisms with eventual volume expansionOct 21 2009We consider smooth maps on compact Riemannian manifolds. We prove that under some mild condition of eventual volume expansion Lebesgue almost everywhere we have uniform backward volume contraction on every pre-orbit of Lebesgue almost every point.
Suppressing vacuum fluctuations with vortex excitationsOct 22 2015The Casimir force for a planar gauge model is studied considering perfect conducting and perfect magnetically permeable boundaries. By using an effective model describing planar vortex excitations, we determine the effect these can have on the Casimir ... More
ESPRESSO's Early Commissioning Results and Performance Related to Tests of Fundamental Constant StabilityDec 14 2018ESPRESSO is a new high-resolution ultra-stable spectrograph for the VLT, which had its first light on Telescope on November 27th, 2017. The instrument is installed in the Combined Coud\'{e} Laboratory and linked to the 4 Units of Telescope through optical ... More
2MASS wide field extinction maps - I. The Pipe nebulaJun 27 2006We present a 8 deg x 6 deg, high resolution extinction map of the Pipe nebula using 4.5 million stars from the Two Micron All Sky Survey (2MASS) point source catalog. The use of NICER, a robust and optimal technique to map the dust column density, allows ... More
Dust properties of the dark cloud IC5146 - Submillimeter and NIR imagingDec 11 2002Dec 12 2002We present the results of a submillimeter dust continuum study of a molecular ridge in IC5146 carried out at 850micron and 450micron with SCUBA on the James Clerk Maxwell Telescope (JCMT). The mapped region is 14'x2.5' in size (2pc x 0.3pc) and consists ... More
Time-dependent cosmological constant in the Jackiw-Teitelboim cosmologyJul 26 2002Mar 11 2003We study the obtainment of a time-dependent cosmological constant at D=2 in a model based on the Jackiw-Teitelboim cosmology. We show that the cosmological term goes to zero asymptotically and can induce a nonsingular behavior at the origin.
Formation of Lunar SwirlsMay 23 2015In this paper we show a plausible mechanism that could lead to the formation of the Dark Lanes in Lunar Swirls, and the electromagnetic shielding of the lunar surface that results in the preservation of the white colour of the lunar regolith. We present ... More
Higgs Signals in a Type I 2HDM or with a Sister HiggsJul 23 2012In models where an additional SU(2)-doublet that does not have couplings to fermions participates in electroweak symmetry breaking, the properties of the Higgs boson are changed. At tree level, in the neighborhood of the SM-like range of parameter space, ... More
Gravitational collapse of the OMC-1 regionMar 09 2017Mar 29 2017We have investigated the global dynamical state of the Integral Shaped Filament in the Orion A cloud using new N$_2$H$^+$ (1-0) large-scale, IRAM30m observations. Our analysis of its internal gas dynamics reveals the presence of accelerated motions towards ... More
A new old class of maximal monotone operatorsMay 29 2008In a recent paper in Journal of Convex Analysis the authors studied, in non-reflexive Banach spaces, a class of maximal monotone operators, characterized by the existence of a function in Fitzpatrick's family of the operator which conjugate is above the ... More
Bronsted-Rockafellar property and maximality of monotone operators representable by convex functions in non-reflexive Banach spacesFeb 13 2008In this work we are concerned with maximality of monotone operators representable by certain convex functions in non-reflexive Banach spaces. We also prove that these maximal monotone operators satisfy a Bronsted-Rockafellar type property. We show that ... More
Estimating Extinction using Unsupervised Machine LearningFeb 27 2017Dust extinction is the most robust tracer of the gas distribution in the interstellar medium, but measuring extinction is limited by the systematic uncertainties involved in estimating the intrinsic colors to background stars. In this paper we present ... More
Fitting tails affected by truncationJun 07 2016May 05 2017In several applications, ultimately at the largest data, truncation effects can be observed when analysing tail characteristics of statistical distributions. In some cases truncation effects are forecasted through physical models such as the Gutenberg-Richter ... More
A general estimator for the right endpoint - with an application to supercentenarian women's recordsDec 12 2014Jun 16 2016We extend the setting of the right endpoint estimator introduced in Fraga Alves and Neves (Statist. Sinica 24:1811--1835, 2014) to the broader class of light-tailed distributions with finite endpoint, belonging to some domain of attraction induced by ... More
Band-like transport and trapping in TMTSF Single Crystal TransistorsJul 13 2009We perform a combined experimental and theoretical study of tetramethyltetraselenafulvalene (TMTSF) single-crystal field-effect transistors, whose electrical characteristics exhibit clear signatures of the intrinsic transport properties of the material. ... More
Screening Length in 2+1-dimensional Abelian Chern-Simons TheoriesJan 25 2002Mar 17 2002In this paper, we systematically study the question of screening length in Abelian Chern-Simons theories. In the Abelian Higgs theory, where there are two massive poles in the gauge propagator at the tree level, we show that the coefficient of one of ... More
Mass reservoirs surrounding massive infrared dark clouds: A view by near-infrared dust extinctionSep 27 2011Context: Infrared Dark Clouds (IRDCs) harbor progenitors of high-mass stars. Little is known of the parental molecular clouds of the IRDCs. Aims: We demonstrate the feasibility of the near-infrared (NIR) dust extinction mapping in tracing the parental ... More
No evidence for mass segregation in massive young clustersNov 19 2008Dec 04 2008Aims. We investigate the validity of the mass segregation indicators commonly used in analysing young stellar clusters. Methods. We simulate observations by constructing synthetic seeing-limited images of a 1000 massive clusters (10^4 Msun) with a standard ... More
The Musca cloud: A 6 pc-long velocity-coherent, sonic filamentNov 19 2015Dec 08 2015Filaments play a central role in the molecular clouds' evolution, but their internal dynamical properties remain poorly characterized. To further explore the physical state of these structures, we have investigated the kinematic properties of the Musca ... More
On the volume of singular-hyperbolic setsSep 14 2005Sep 11 2006An attractor $\Lambda$ for a 3-vector field $X$ is singular-hyperbolic if all its singularities are hyperbolic and it is partially hyperbolic with volume expanding central direction. We prove that $C^{1+\alpha}$ singular-hyperbolic attractors, for some ... More
A simple agent-based spatial model of the economy: tools for policyOct 16 2015Feb 06 2016This study simulates the evolution of artificial economies in order to understand the tax relevance of administrative boundaries in the quality of life of its citizens. The modeling involves the construction of a computational algorithm, which includes ... More
Pavlovian Prisoner's Dilemma in one-dimensional cellular automata: analytical results, the quasi-regular phase, spatio-temporal patterns and parameter space explorationApr 02 2009The Prisoner's Dilemma (PD) game is used in several fields due to the emergence of cooperation among selfish players. Here, we have considered a one-dimensional lattice, where each cell represents a player, that can cooperate or defect. This one-dimensional ... More
Lower Limits of Type (D) Monotone Operators in general Banach SpacesDec 19 2014We give, for general Banach spaces, a characterization of the sequential lower limit of maximal monotone operators of type (D) and prove its representability. As a consequence, using a recent extension of the Moreau-Yosida regularization for type (D) ... More
Fixed Points of Generalized ConjugationsFeb 15 2008Conjugation, or Legendre transformation, is a basic tool in convex analysis, rational mechanics, economics and optimization. It maps a function on a linear topological space into another one, defined in the dual of the linear space by coupling these space ... More
On existence and concentration of solutions to a class of quasilinear problems involving the $1-$Laplace operatorFeb 22 2017In this work we use variational methods to prove results on existence and concentration of solutions to a problem in $\mathbb{R}^N$ involving the $1-$Laplacian operator. A thorough analysis on the energy functional defined in the space of functions of ... More
Tail fitting for truncated and non-truncated Pareto-type distributionsMay 19 2015Recently some papers, such as Aban, Meerschaert and Panorska (2006), Nuyts (2010) and Clark (2013), have drawn attention to possible truncation in Pareto tail modelling. Sometimes natural upper bounds exist that truncate the probability tail, such as ... More
Multiplicity results for a class of quasilinear equations with exponential critical growthSep 30 2015In this work, we prove the existence and multiplicity of positive solutions for the following class of quasilinear elliptic equations $$ \left \{ \begin{array}{lll} -\epsilon^{N}\Delta_{N} u + \left(1+\mu A(x) \right)\left| u\right|^{N-2}u= f(u)\,\,\,\, ... More
Light-front field theories at finite temperatureSep 04 2002We study the question of generalizing light-front field theories to finite temperature. We show that the naive generalization has serious problems and we identify the source of the difficulty. We provide a proper generalization of these theories to finite ... More
Existence, multiplicity and concentration for a class of fractional $p\&q$ Laplacian problems in $\mathbb{R}^{N}$Jan 30 2019In this work we consider the following class of fractional $p\&q$ Laplacian problems \begin{equation*} (-\Delta)_{p}^{s}u+ (-\Delta)_{q}^{s}u + V(\varepsilon x) (|u|^{p-2}u + |u|^{q-2}u)= f(u) \mbox{ in } \mathbb{R}^{N}, \end{equation*} where $\varepsilon>0$ ... More