Results for "Ulisses Braga-Neto"

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Control of Gene Regulatory Networks with Noisy Measurements and Uncertain InputsFeb 24 2017This paper is concerned with the problem of stochastic control of gene regulatory networks (GRNs) observed indirectly through noisy measurements and with uncertainty in the intervention inputs. The partial observability of the gene states and uncertainty ... More
Particle Filters for Partially-Observed Boolean Dynamical SystemsFeb 23 2017Partially-observed Boolean dynamical systems (POBDS) are a general class of nonlinear models with application in estimation and control of Boolean processes based on noisy and incomplete measurements. The optimal minimum mean square error (MMSE) algorithms ... More
Rank discriminants for predicting phenotypes from RNA expressionJan 07 2014Nov 21 2014Statistical methods for analyzing large-scale biomolecular data are commonplace in computational biology. A notable example is phenotype prediction from gene expression data, for instance, detecting human cancers, differentiating subtypes and predicting ... More
GAIA Spectroscopy and Radial VelocitiesSep 05 2001GAIA spectroscopic and radial velocity performancies are reviewed on the base of ground-based test observations and simulations. The prospects for accurate analysis of stellar atmospheres (temperature, gravity, chemical abundances, rotation, peculiarities) ... More
Sequential Experimental Design for Optimal Structural Intervention in Gene Regulatory Networks Based on the Mean Objective Cost of UncertaintyMay 30 2018Scientists are attempting to use models of ever increasing complexity, especially in medicine, where gene-based diseases such as cancer require better modeling of cell regulation. Complex models suffer from uncertainty and experiments are needed to reduce ... More
Scalable optimal Bayesian classification of single-cell trajectories under regulatory model uncertaintyFeb 08 2019Single-cell gene expression measurements offer opportunities in deriving mechanistic understanding of complex diseases, including cancer. However, due to the complex regulatory machinery of the cell, gene regulatory network (GRN) model inference based ... More
The Diffuse Interstellar Band at 8620 Ang: a good reddening tracer for GAIAOct 13 2000We report about a suprisingly good correlation between the equivalent width of the diffuse interstellar band (DIB) at 8620 Ang and the interstellar reddening. Such a correlation offers bright prospects in using the 8620 Ang DIB as a tracer of the exctinction ... More
Finite thermoelastoplasticity and creep under small elastic strainsApr 16 2018A mathematical model for an elastoplastic continuum subject to large strains is presented. The inelastic response is modeled within the frame of rate-dependent gradient plasticity for nonsimple materials. Heat diffuses through the continuum by the Fourier ... More
Doubly nonlinear stochastic evolution equationsMay 27 2019Jul 02 2019We present an existence theory for martingale and strong solutions to doubly nonlinear evolution equations in a separable Hilbert space in the form $$d(Au) + Bu\,dt \ni F(u)\,dt + G(u)\,dW$$ where both $A$ and $B$ are maximal monotone operators, possibly ... More
A multicolor CCD photometric study of the open clusters NGC 2866, Pismis 19, Westerlund 2, ESO96-SC04, NGC 5617 and NGC 6204Sep 26 2003Accurate and deep BVI CCD photometry is presented for the core regions of six southern compact open clusters (supplemented in one case by U and R bands). These clusters generally have only scanty photometric data published, in some case only photoelectric ... More
Spectroscopy, Photometry and Micro-arcsec Astrometry of Binaries with the GAIA Space Mission and with the RAVE ExperimentJun 01 2003GAIA astrometric mission of ESA will be very efficient in discovering binary and multiple stars with any orbital period, from minutes to millions of years. Main parameters of the revised mission design are presented. Next we estimate the fraction of binary ... More
On the narrow emission line components of the LMC novae 2004 (YY Dor) and 2009aAug 18 2014We present early decline spectra of the two Large Magellanic Cloud novae: LMC 2004 (YY Dor) and LMC 2009a and discuss their spectral an line profile evolution with special emphasis on the existence and appearance of a sharp component. We show that the ... More
Ripples in graphene: A variational approachFeb 14 2018Feb 15 2018Suspended graphene samples are observed to be gently rippled rather than being flat. In [M. Friedrich, U. Stefanelli. Graphene ground states, arXiv:1802.05049], we have checked that this nonplanarity can be rigorously described within the classical molecular-mechanical ... More
Thermodynamics of elastoplastic porous rocks at large strains towards earthquake modelingJul 02 2018Jul 05 2018A mathematical model for an elastoplastic porous continuum subject to large strains in combination with reversible damage (aging), evolving porosity, water and heat transfer is advanced. The inelastic response is modeled within the frame of plasticity ... More
Coarse and uniform embeddingsDec 09 2015Dec 22 2016In these notes, we study the relation between uniform and coarse embeddings between Banach spaces. In order to understand this relation better, we also look at the problem of when a coarse embedding can be assumed to be topological. Among other results, ... More
Information versus stability in an anti-de Sitter black holeJul 12 2019Information entropies associated with the energy density in position and momentum spaces are build for an anti-de Sitter (AdS) black hole. These quantities, that satisfy an entropic uncertainty relation, vary with the temperature. The higher is the black ... More
Coarse and uniform embeddingsDec 09 2015In these notes, we study the relation between uniform and coarse embeddings between Banach spaces. In order to understand this relation better, we also look at the problem of when a coarse embedding can be assumed to be topological. Among other results, ... More
On weaker notions of nonlinear embeddings between Banach spacesJul 20 2016In this paper, we study nonlinear embeddings between Banach spaces. More specifically, the goal of this paper is to study weaker versions of coarse and uniform embeddability, and to provide suggestive evidences that those weaker embeddings may be stronger ... More
On asymptotically uniformly smoothness and nonlinear geometry of Banach spacesAug 09 2018These notes concern the nonlinear geometry of Banach spaces, asymptotic uniform smoothness and several Banach-Saks-like properties. We study the existence of certain concentration inequalities in asymptotically uniformly smooth Banach spaces as well as ... More
On the complexity of some inevitable classes of separable Banach spacesAug 08 2015In this paper, we study the descriptive complexity of some inevitable classes of Banach spaces. Precisely, as shown in [Go], every Banach space either contains a hereditarily indecomposable subspace or an unconditional basis, and, as shown in [FR], every ... More
Nonlinear weakly sequentially continuous embeddings between Banach spacesOct 21 2017In these notes, we study nonlinear embeddings between Banach spaces which are also weakly sequentially continuous. In particular, our main result implies that if a Banach space $X$ coarsely (resp. uniformly) embeds into a Banach space $Y$ by a weakly ... More
The geometry of C_60: a rigorous approach via Molecular MechanicsApr 07 2016Molecular Mechanics describes molecules as particle configurations interacting via classical potentials. These {\it configurational energies} usually consist of the sum of different phenomenological terms which are tailored to the description of specific ... More
A Simple Method to Test for Energy-Dependent Dispersion in High Energy Light-Curves of Astrophysical SourcesApr 10 2012In this paper we discuss a simple method of testing for the presence of energy-dependent dispersion in high energy data-sets. It uses the minimisation of the Kolmogorov distance between the cumulative distribution of two probability functions as the statistical ... More
Enhanced emission from GRB 110328A could be evidence for tidal disruption of a starApr 13 2011Apr 28 2011On March 28, Swift's Burst Alert Telescope discovered a source in the constellation Draco when it erupted in a series of X-ray blasts. The explosion, catalogued as gamma-ray burst (GRB) 110328A, repeatedly flared in the following days, making the interpretation ... More
Optimal control of a rate-independent evolution equation via viscous regularizationJul 04 2016We study the optimal control of a rate-independent system that is driven by a convex, quadratic energy. Since the associated solution mapping is non-smooth, the analysis of such control problems is challenging. In order to derive optimality conditions, ... More
Random versus maximum entropy models of neural population activityDec 08 2016The principle of maximum entropy provides a useful method for inferring statistical mechanics models from observations in correlated systems, and is widely used in a variety of fields where accurate data are available. While the assumptions underlying ... More
Attractors for gradient flows of non convex functionals and applicationsMay 31 2007This paper addresses the long-time behavior of gradient flows of non convex functionals in Hilbert spaces. Exploiting the notion of generalized semiflows by J. M. Ball, we provide some sufficient conditions for the existence of a global attractor. The ... More
Configurational Temperature Control for Atomic and Molecular SystemsSep 11 2007A new configurational temperature thermostat suitable for molecules with holonomic constraints is derived. This thermostat has a simple set of motion equations, can generate the canonical ensemble in both position and momentum space, acts homogeneously ... More
Existence results for incompressible magnetoelasticityNov 16 2013Nov 29 2013We investigate a variational theory for magnetoelastic solids under the incompressibility constraint. The state of the system is described by deformation and magnetization. While the former is classically related to the reference configuration, magnetization ... More
Well-posedness and long-time behavior for a class of doubly nonlinear equationsNov 03 2006This paper addresses a doubly nonlinear parabolic inclusion of the form $A(u_t)+B(u)\ni f$. Existence of a solution is proved under suitable monotonicity, coercivity, and structure assumptions on the operators $A$ and $B$, which in particular are both ... More
Off-line Programming and Simulation from CAD Drawings: Robot-Assisted Sheet Metal BendingNov 18 2013Increasingly, industrial robots are being used in production systems. This is because they are highly flexible machines and economically competitive with human labor. The problem is that they are difficult to program. Thus, manufacturing system designers ... More
Numerical modeling of friction stir welding process: a literature reviewNov 18 2013This survey presents a literature review on friction stir welding (FSW) modeling with a special focus on the heat generation due to the contact conditions between the FSW tool and the workpiece. The physical process is described and the main process parameters ... More
Extracting stellar parameters from observed spectra: the role of cross-correlation and minimum distance methodsDec 03 2004One may consider cross-correlation routines applied to stellar spectra as a way to determine not only the radial velocities but also to assess the properties of stellar atmospheres. We show that this is not the case. High value of the cross-correlation ... More
A rate-independent model for the isothermal quasi-static evolution of shape-memory materialsAug 31 2007This note addresses a three-dimensional model for isothermal stress-induced transformation in shape-memory polycrystalline materials. We treat the problem within the framework of the energetic formulation of rate-independent processes and investigate ... More
Dynamic perfect plasticity and damage in viscoelastic solidsApr 03 2019In this paper we analyze an isothermal and isotropic model for viscoelastic media combining linearized perfect plasticity (allowing for concentration of plastic strain and development of shear bands) and damage effects in a dynamic setting. The interplay ... More
Observational Studies of Early-type Binary Stars: MP CentauriMar 29 2005We present photometric and spectroscopic data on the early-type binary MP Centauri. The photometric data are analyzed simultaneously with radial velocities to derive preliminary absolute dimensions for the binary components. Analysis of the spectra shows ... More
Status of the Cherenkov Telescope Array ProjectJan 18 2016Gamma-ray astronomy holds a great potential for Astrophysics, Particle Physics and Cosmology. The CTA is an inter- national initiative to build the next generation of ground-based gamma-ray observatories, which will represent a factor of 5-10 times improvement ... More
The maximum time of 2-neighbor bootstrap percolation: complexity resultsAug 27 2015In 2-neighborhood bootstrap percolation on a graph G, an infection spreads according to the following deterministic rule: infected vertices of G remain infected forever and in consecutive rounds healthy vertices with at least 2 already infected neighbors ... More
Chiral Decomposition For Non-Abelian BosonsAug 28 1996We study the non-abelian extension for the splitting of a scalar field into chiral components. Using this procedure we find a non ambiguous way of coupling a non abelian chiral scalar field to gravity. We start with a (non-chiral) WZW model covariantly ... More
Thermal width of heavy quarkonia from an AdS/QCD modelJun 30 2016We estimate the thermal width of a heavy quark anti-quark pair inside a strongly coupled plasma using a holographic AdS/QCD model. The imaginary part of the quark potential that produces the thermal width appears in the gravity dual from quantum fluctuations ... More
COUPLING CHIRAL BOSONS TO GRAVITYJan 18 1995The chiral boson actions of Floreanini and Jackiw (FJ), and of McClain,Wu and Yu (MWY) have been recently shown to be different representations of the same chiral boson theory. MWY displays manifest covariance and also a (gauge) symmetry that is hidden ... More
Chiral Bosons as solutions of the BV master equation 2D chiral gauge theoriesFeb 25 1994We construct the chiral Wess-Zumino term as a solution for the Batalin-Vilkovisky master equation for anomalous two-dimensional gauge theories, working in an extended field-antifield space, where the gauge group elements are introduced as additional degrees ... More
Relativistic energy of a moving spherical capacitorNov 28 2007We discuss the relativistic transformation of the energy of a charged spherical capacitor. The energy stored in the electromagnetic fields observed by an uniformly moving frame is related to that of the rest frame by a factor different from $\gamma $. ... More
Quasinormal modes and dispersion relations for quarkonium in a plasmaOct 28 2018Jan 05 2019Recent investigations show that the thermal spectral function of heavy $ {b \bar b } $ and $ {c \bar c} $ vector mesons can be described using holography. These studies consider a bottom up model that captures the heavy flavour spectroscopy of masses ... More
On the uniform Roe algebra as a Banach algebra and embeddings of $\ell_p$ uniform Roe algebrasJun 27 2019Jun 28 2019We work on $\ell_p$ uniform Roe algebras associated to metric spaces, and on their mutual embedding. We generalize results of I. Farah and the authors to mutual embeddings of uniform Roe algebras of operators on $\ell_p$ spaces. Simultaneously, we obtain ... More
On the rigidity of uniform Roe algebras over uniformly locally finite coarse spacesMay 11 2018Given a coarse space $(X,\mathcal{E})$, one can define a $\mathrm{C}^*$-algebra $\mathrm{C}^*_u(X)$ called the uniform Roe algebra of $(X,\mathcal{E})$. It has been proved by J. \v{S}pakula and R. Willett that if the uniform Roe algebras of two uniformly ... More
A Semi-Supervised Self-Organizing Map with Adaptive Local ThresholdsJul 01 2019In the recent years, there is a growing interest in semi-supervised learning, since, in many learning tasks, there is a plentiful supply of unlabeled data, but insufficient labeled ones. Hence, Semi-Supervised learning models can benefit from both types ... More
Strong interactions and gauge/string dualitySep 13 2006May 08 2007We discuss some recent phenomenological models for strong interactions based on the idea of gauge/string duality. A very good estimate for hadronic masses can be found by placing an infrared cut off in AdS space. Considering static strings in this geometry ... More
Resilience Analysis for Competing PopulationsMar 14 2019Ecological resilience refers to the ability of a system to retain its state when subject to state variables perturbations or parameter changes. While understanding and quantifying resilience is crucial to anticipate the possible regime shifts, characterizing ... More
Resilience Analysis for Competing PopulationsMar 14 2019Mar 28 2019Ecological resilience refers to the ability of a system to retain its state when subject to state variables perturbations or parameter changes. While understanding and quantifying resilience is crucial to anticipate the possible regime shifts, characterizing ... More
On the two-steps relaxation of mean-field glasses: p-spin modelFeb 19 2012Critical slowing down dynamics of supercooled glass-forming liquids is usually understood at the mean-field level in the framework of Mode Coupling Theory, providing a two-time relaxation scenario and power-law behaviors of the time correlation function ... More
Predicting synchronous firing of large neural populations from sequential recordingsApr 09 2019A major goal in neuroscience is to understand how populations of neurons code for stimuli or actions. While the number of neurons that can be recorded simultaneously is increasing at a fast pace, in most cases these recordings cannot access a complete ... More
Microlocal Versal Deformations of Plane CurvesDec 04 2009We introduce the notion of microlocal versal deformation of a plane curve. We construct equisingular versal deformations of Legendrian curves that are the conormal of a semi-quasi-homogeneous branch.
Fundamental Constants, Entropic Gravity and Nonextensive Equipartition TheoremJan 14 2011Apr 23 2012By using the Verlinde's formalism[1], we propose that the positive numerical factor, in which Klinkhamer[2] states that it is necessary to define the fundamental length, can be associated to the parameter q of the Tsallis' nonextensive statistical mechanics[3]. ... More
Nonhomogeneous Cooling, Entropic Gravity and MOND TheorySep 24 2010Jun 20 2011In this paper, by using the holographic principle, a modified equipartition theorem where we assume that below a critical temperature the energy is not equally divided on all bits, and the Unruh temperature, we derive MOND theory and a modified Friedmann ... More
Gauging by Stückelberg field-shifting symmetryMay 14 2003Aug 13 2003We embed second class constrained systems by a formalism that combines concepts of the BFFT method and the unfixing gauge formalism. As a result, we obtain a gauge-invariant system where the introduction of the Wess-Zumino (WZ) field is essential. The ... More
The Gauge Unfixing Formalism and the Solutions of the Dirac Bracket CommutatorsApr 29 2009Sep 04 2009We propose a systematic procedure that solves the Dirac bracket commutators. The method is based on the Gauge Unfixing formalism, a procedure that converts second class systems into first class ones without the enlargement of the original phase space ... More
Using permutations to detect, quantify and correct for confounding in machine learning predictionsMay 18 2018Nov 27 2018Clinical machine learning applications are often plagued with confounders that are clinically irrelevant, but can still artificially boost the predictive performance of the algorithms. Confounding is especially problematic in mobile health studies run ... More
Detecting Learning vs Memorization in Deep Neural Networks using Shared Structure Validation SetsFeb 21 2018The roles played by learning and memorization represent an important topic in deep learning research. Recent work on this subject has shown that the optimization behavior of DNNs trained on shuffled labels is qualitatively different from DNNs trained ... More
Dynamical Casimir effect with cylindrical waveguidesAug 03 2004I consider the quantum electromagnetic field in a coaxial cylindrical waveguide, such that the outer cylindrical surface has a time-dependent radius. The field propagates parallel to the axis, inside the annular region between the two cylindrical surfaces. ... More
Theory of tangential idealizers and tangentially free idealsAug 06 2009Jun 20 2017We generalize the theory of logarithmic derivations through a self-contained study of modules here dubbed tangential idealizers. We establish reflexiveness criteria for such modules, provided the ring is a factorial domain. As a main consequence, necessary ... More
Theory of tangential idealizers and tangentially free idealsAug 06 2009Oct 07 2009We generalize the theory of logarithmic derivations through a self-contained study of modules here dubbed tangential idealizers. We establish reflexiveness criteria for such modules, provided the ring is a factorial domain. As a main consequence, necessary ... More
Charge stripe order from antiphase spin spirals in the spin-Fermion modelSep 21 2006We revisit the ground state of the spin-Fermion model within a semiclassical approximation. We demonstrate that antiphase spin spirals, or pi-spirals, whose chirality alternates between consecutive rows (or columns) of local moments, have, for sufficiently ... More
Stability of constant mean curvature surfaces in three dimensional warped product manifoldsMar 07 2018Mar 07 2019In this paper we prove that stable, compact without boundary, oriented, nonzero constant mean curvature surfaces in the de Sitter-Schwarzschild and Reissner-Nordstrom manifolds are the slices, provided its mean curvature satisfies some positive lower ... More
NON-POLYNOMIAL LAGRANGIANS IN THE SKYRME MODELApr 03 1995We choose three different coupling constants for a particular higher-derivative term in the Skyrme model that allows the total Lagrangian to converge in a binomial, geometric and a logarithmic form. Improved numerical results are obtained.
Remarks on the Collective Quantization of the SU(2) Skyrme ModelJan 03 1994We point out the question of ordering momentum operator in the canonical \break quantization of the SU(2) Skyrme Model. Thus, we suggest a new definition for the momentum operator that may solve the infrared problem that appears when we try to minimize ... More
On the topology of families of isolated singularitiesNov 27 2014Dec 03 2014We study the topology of analytic families of $n$-dimensional complex hypersurfaces having an isolated singularity at the origin. We prove that such a family is $\mu$-constant if and only if it admits an uniform Milnor radius, which happens if and only ... More
Stripes, Vibrations and SuperconductivityFeb 15 2001Mar 20 2001We propose a model of a spatially modulated collective charge state of superconducting cuprates. The regions of higher carrier density (stripes) are described in terms of Luttinger liquids and the regions of lower density as a two-dimensional interacting ... More
Non-Fermi liquid behavior in U and Ce intermetallicsNov 06 1999Dec 06 1999In this paper we review the current experimental and theoretical situation of the description of non-Fermi liquid behavior (NFL) in U and Ce intermetallics. We focus on the magnetic and thermodynamic properties. We also discuss a recent theoretical interpretation ... More
Lê's polyhedron for line singularitiesFeb 05 2012Nov 27 2014We study the topology of a line singularity, which is a complex hypersurface with non-isolated singularity given by a complex line. We describe the degeneration of its Milnor fibre to the singular hypersurface by means of a pair of polyhedra, one in the ... More
Direct off-line robot programming via a common CAD packageSep 09 2013This paper focuses on intuitive and direct off-line robot programming from a CAD drawing running on a common 3-D CAD package. It explores the most suitable way to represent robot motion in a CAD drawing, how to automatically extract such motion data from ... More
Solar observations with Rio de Janeiro Danjon astrolabe: diameter variations and its correlations (1998-2000)Jan 14 2013This work has aimed to analyze the 1998 to 2000 campaign of solar diameter surveying. The employed instrument was a Danjon astrolabe, at the Observat\'orio Nacional campus, and specially modified for the solar observations. During the time lapse, 10807 ... More
Stability of constant mean curvature surfaces in three dimensional warped product manifoldsMar 07 2018In this paper we prove that stable, compact without boundary, oriented, constant mean curvature surfaces in the de Sitter-Schwarzschild and Reissner-Nordstrom manifolds are the slices, provided its mean curvature satisfies some lower bound. More generally, ... More
Limits of Tangents of SurfacesNov 25 2015We compute the limit of tangents of an arbitrary surface. We obtain as a byproduct an embedded version of Jung's desingularization theorem for surface singularities with finite limits of tangents.
Limits of Tangents of a Quasi-Ordinary HypersurfaceMar 24 2010We compute explicitly the limits of tangents of a quasi-ordinary singularity in terms of its special monomials. We show that the set of limits of tangents of Y is essentially a topological invariant of Y .
An improved Gauge Unfixing formalism and the Abelian Pure Chern Simons TheorySep 29 2006Jul 05 2007We propose a variant scheme of the Gauge Unfixing formalism which modifies directly the original phase space variables of a constrained system. These new variables are gauge invariant quantities. We apply our procedure in a mixed constrained system that ... More
Magneto-elastic coupling between copper spin configurations and oxygen octahedra in La(2-x)Sr(x)CuO(4). Untwinning, Raman (phonon) spectrum, and neutron responseFeb 21 2006Jun 12 2006We reinterpret neutron scattering and Raman spectroscopy experiments in La(2-x)Sr(x)CuO(4), showing modulation of spin and lattice degrees of freedom both in the low-temperature orthorhombic and tetragonal phases, in terms of a magneto-elastic coupling ... More
Using instrumental variables to disentangle treatment and placebo effects in blinded and unblinded randomized clinical trials influenced by unmeasured confoundersJun 15 2016Jun 21 2016Clinical trials traditionally employ blinding as a design mechanism to reduce the influence of placebo effects. In practice, however, it can be difficult or impossible to blind study participants and unblinded trials are common in medical research. Here ... More
Magnon squeezing in an antiferromagnet: reducing the spin noise below the standard quantum limitNov 13 2003At absolute zero temperature, thermal noise vanishes when a physical system is in its ground state, but quantum noise remains as a fundamental limit to the accuracy of experimental measurements. Such a limitation, however, can be mitigated by the formation ... More
The Frustration in being Odd: area law violation in local systemsJul 18 2018We demonstrate the existence of a new quantum phase of matter that arises in antiferromagnetic spin chains with a weak frustration -just one bond in a large chain-. This is the case, for instance, of systems with an odd number of spins with periodic boundary ... More
Comparison between Laplace-Lagrange Secular Theory and Numerical SimulationJun 08 2018The large increase in exoplanet discoveries in the last two decades showed a variety of systems whose stability is not clear. In this work we chose the $\upsilon$ Andromedae system as the basis of our studies in dynamical stability. This system has a ... More
Inhomogeneous Hopf-Oleĭnik Lemma and Applications. Part IV: Sharp Krylov Boundary Gradient Type Estimates for Solutions to Fully Nonlinear Differential Inequalities with unbounded coefficients and $C^{1,Dini}$ boundary dataAug 08 2016In this paper we provide another application of the Inhomogeneous Hopf-Ole\u{i}nik Lemma (IHOL) proved in \cite{BM-IHOL-PartI}. As a matter of fact, we also provide a new and simpler proof of IHOL with unbounded coefficients but only for the the fully ... More
A SUPERSPACE FORMULATION FOR THE BATALIN VILKOVISKY FORMALISM WITH EXTENDED BRST INVARIANCEMay 02 1995A superspace formulation for the Batalin Vilkovisky formalism (also called field-antifield quantization ) with extended BRST invariance (BRST and anti-BRST invariance ) for gauge theories with closed algebra is presented. In contrast to a recent formulation, ... More
Hopf Bifurcations in a Watt Governor With a SpringFeb 29 2008Mar 04 2008This paper pursues the study carried out by the authors in "Stability and Hopf bifurcation in a hexagonal governor system", focusing on the codimension one Hopf bifurcations in the hexagonal Watt governor differential system. Here are studied the codimension ... More
Lyapunov Coefficients for Degenerate Hopf BifurcationsSep 25 2007In this paper are studied the codimensions one, two, three and four Hopf bifurcations and the pertinent Lyapunov stability coefficients. Algebraic expressions obtained with computer assisted calculations are displayed.
Holographic model for heavy vector meson massesNov 19 2015Sep 15 2016The experimentally observed spectra of heavy vector meson radial excitations show a dependence on two different energy parameters. One is associated with the quark mass and the other with the binding energy levels of the quark anti-quark pair. The first ... More
Thermal dissociation of heavy mesons and configurational entropyAug 30 2018Oct 31 2018We study the dissociation of heavy vector mesons in a thermal medium from the point of view of the configurational entropy. Bottomonium and charmonium vector mesons in a plasma are represented using a holographic AdS/QCD model. The quasinormal modes, ... More
Stability and Hopf Bifurcation in the Watt Governor SystemApr 07 2006In this paper we study the Lyapunov stability and Hopf bifurcation in a system coupling a Watt-centrifugal-governor with a steam-engine. Sufficient conditions for the stability of the equilibrium state in terms of the physical parameters and of the bifurcating ... More
Holographic model for charmonium dissociationSep 15 2017Oct 12 2017We present a holographic bottom up model for the thermal behavior of $ c \bar c$ vector mesons in a finite temperature and density plasma. There is a clear physical interpretation for the three imput energy parameters of the model. Two of them are related ... More
Measurement of the ortho-positronium confinement energy in mesoporous thin filmsJan 12 2010May 03 2010In this paper, we present measurements of the ortho-positronium emission energy in vacuum from mesoporous films using the time of flight technique. We show evidence of quantum mechanical confinement in the mesopores that defines the minimal energy of ... More
Precoding and Spatial Modulation in the Downlink of MU-MIMO SystemsMar 05 2018Mar 19 2018This work focuses on the downlink communication of a multiuser MIMO system where the base station antennas and the users' receiving antennas are all active, but at each transmission, only a subset of the receive antennas is selected by the base station ... More
Deformations of Legendrian CurvesJul 11 2016We construct versal and equimultiple versal deformations of the parametrization of a Legendrian curve.
Bessel Integrals and Fundamental Solutions for a Generalized Tricomi OperatorJan 08 2001Partial Fourier transforms are used to find explicit formulas for two remarkable fundamental solutions for a generalized Tricomi operator. These fundamental solutions reflect clearly the mixed type of the operator. In order to prove these results, we ... More
On the classification of noncompact steady quasi-Einstein manifold with vanishing condition on the Weyl tensorSep 21 2017Oct 03 2017The aim of this paper is to study complete (noncompact) steady $m$-quasi-Einstein manifolds satisfying a fourth-order vanishing condition on the Weyl tensor. In this case, we are able to prove that a steady $m$-quasi-Einstein manifold ($m>1$) on a simply ... More
Casimir force between $δ-δ^{\prime}$ mirrors transparent at high frequenciesJul 21 2016Aug 14 2016We investigate, in the context of a real massless scalar field in $1+1$ dimensions, models of partially reflecting mirrors simulated by Dirac $\delta-\delta^{\prime}$ point interactions. In the literature, these models do not exhibit full transparency ... More
All Optical Implementation of Multi-Spin Entanglement in a Semiconductor Quantum WellJun 27 2002We use ultrafast optical pulses and coherent techniques to create spin entangled states of non-interacting electrons bound to donors (at least three) and at least two Mn2+ ions in a CdTe quantum well. Our method, relying on the exchange interaction between ... More
Quantitative Determination of the Band-Gap of WS2 with Ambipolar Ionic Liquid-Gated TransistorsFeb 06 2013We realized ambipolar Field-Effect Transistors by coupling exfoliated thin flakes of tungsten disulphide (WS2) with an ionic liquid-dielectric. The devices show ideal electrical characteristics, including very steep sub-threshold slopes for both electrons ... More
The role of magnetic field for quiescence-outburst models in CVsDec 19 2014In this paper we present the elementary assumptions of our research on the role of the magnetic field in modelling the quiescence-outbursts cycle in Cataclysmic Variables (CVs). The behaviour of the magnetic field is crucial not only to integrate the ... More
Embeddings of uniform Roe algebrasApr 15 2019Jun 27 2019In this paper, we study embeddings of uniform Roe algebras. Generally speaking, given metric spaces $X$ and $Y$, we are interested in which large scale geometric properties are stable under embedding of the uniform Roe algebra of $X$ into the uniform ... More
Coarse Baum-Connes conjecture and rigidity for Roe algebrasJul 24 2019In this paper, we connect the rigidity problem and the coarse Baum-Connes conjecture for Roe algebras. In particular, we show that if $X$ and $Y$ are two uniformly locally finite metric spaces such that their Roe algebras are $*$-isomorphic, then $X$ ... More