Results for "F. F. Faria"

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Probing the unitarity of the renormalizable theory of massive conformal gravityJul 27 2017Apr 03 2018The presence of an unstable massive spin-2 ghost state in the renormalizable theory of massive conformal gravity leads to a pair of complex poles appearing in the first sheet of the energy plane. Here we show that the positions of these poles are gauge ... More
Cosmology in massive conformal gravityOct 19 2014Mar 06 2019In this paper we find the cosmological solutions of the massive conformal gravity field equations in the presence of matter fields. In particular, we show that the solution of negative curvature is in good agreement with our universe.
Reply to "Comment on 'Quantum massive conformal gravity' by F. F. Faria"Aug 03 2016Jan 07 2017Recently in (Eur. Phys. J. C 76:341, 2016) [arXiv:1604.08706], Myung has suggested that the renormalizability of massive conformal gravity is meaningless unless the massive ghost states of the theory are stable. Here we show that massive conformal gravity ... More
Cosmology in massive conformal gravityOct 19 2014Sep 25 2015In this article we find the cosmological solutions of the massive conformal gravity field equations in the presence of matter fields. In particular, we show that the solution of negative spatial curvature is in good agreement with our universe.
A new geometrical approach to metric-affine gravityJul 16 2013Here we consider a metric-affine theory of gravity in which the gravitational Lagrangian is the scalar curvature. The matter action is allowed to depend also on the torsion and the nonmetricity, which are considered as the field variables together with ... More
On the vDVZ discontinuity in massive conformal gravityMar 03 2017Mar 05 2019By taking the massless limit of linearized massive conformal gravity coupled to a source, we show that the theory is free from the vDVZ discontinuity. This result is confirmed when we take the massless limit of the gravitational potential of the theory, ... More
Reply to "Comment on 'Quantum massive conformal gravity' by F. F. Faria"Aug 03 2016Recently in Eur. Phys. J. C 76, 341 (2016) [arXiv:1604.08706] Myung has suggested that the problem with unphysical states in massive conformal gravity, which was pointed in Eur. Phys. J. C 76, 188 (2016), is solved if we quantize the dilaton field in ... More
Comment on "Astrophysical gravitational waves in conformal gravity"Feb 15 2019Recently, in Phys. Rev. D 98, 084002 (2018), an investigation was carried out on the gravitational radiation from binary systems in conformal gravity and massive conformal gravity. According to the authors of the paper, these two theories differ only ... More
Quantum massive conformal gravityMar 14 2015Apr 07 2016We first find the linear approximation of the second plus fourth order derivative massive conformal gravity action. Then we reduce the linearized action to separated second order derivative terms, which allows us to quantize the theory by using the standard ... More
Solar system tests for linear massive conformal gravityApr 08 2016We first find the linearized gravitational field of a static spherically symmetric mass distribution in massive conformal gravity. Then we test this field with two solar system experiments: deflection of light by the sun and radar echo delay. The result ... More
Massive conformal gravityDec 19 2013Dec 15 2014In this article we construct a massive theory of gravity that is invariant under conformal transformations. The massive action of the theory depend on the metric tensor and a scalar field, which are considered as the only field variables. We find the ... More
Conformal theory of everythingMar 09 2019By using conformal symmetry we unify the standard model of particle physics with gravity in a consistent quantum field theory which describes all the fundamental particles and forces of nature.
The electromagnetic field in accelerated framesOct 24 2011We develop a geometrical framework that allows to obtain the electromagnetic field quantities in accelerated frames. The frame of arbitrary accelerated observers in space-time is defined by a suitable set of tetrad fields, whose timelike components are ... More
Conformally invariant teleparallel theories of gravityOct 13 2011Jan 18 2012We analyze the construction of conformal theories of gravity in the realm of teleparallel theories. We first present a family of conformal theories which are quadratic in the torsion tensor and are constructed out of the tetrad field and of a scalar field. ... More
Teleparallel gauge theory of gravityFeb 29 2012Jun 27 2012In this work a tetrad theory of gravity, invariant under conformal transformations, is investigated. The action of the theory is similar to the action of Maxwell's electromagnetism. The role of the electromagnetic gauge potential is played by the trace ... More
On the construction of Fermi-Walker transported framesApr 15 2008We consider tetrad fields as reference frames adapted to observers that move along arbitrary timelike trajectories in spacetime. By means of a local Lorentz transformation we can transform these frames into Fermi-Walker transported frames, which define ... More
On gravitational radiation and the energy flux of matterMay 28 2004A suitable derivative of Einstein's equations in the framework of the teleparallel equivalent of general relativity (TEGR) yields a continuity equation for the gravitational energy-momentum. In particular, the time derivative of the total gravitational ... More
Sparse Choice ModelsNov 19 2010Sep 21 2011Choice models, which capture popular preferences over objects of interest, play a key role in making decisions whose eventual outcome is impacted by human choice behavior. In most scenarios, the choice model, which can effectively be viewed as a distribution ... More
Solution of the $κ$-deformed Dirac equation with scalar, vector and tensor interactions in the context of pseudospin and spin symmetriesApr 17 2017The deformed Dirac equation invariant under the $\kappa$-Poincar\'{e}-Hopf quantum algebra in the context of minimum, vector and scalar couplings under spin and pseudospin symmetric limits is considered. Expressions for the energy eigenvalues and wave ... More
Susceptibility amplitude ratio for generic competing systemsNov 20 2011We calculate the susceptibility amplitude ratio near a generic higher character Lifshitz point up to one-loop order. We employ a renormalization group treatment with $L$ independent scaling transformations associated to the various inequivalent subspaces ... More
A Nonparametric Approach to Modeling Choice with Limited DataOct 01 2009Jun 21 2011A central push in operations models over the last decade has been the incorporation of models of customer choice. Real world implementations of many of these models face the formidable stumbling block of simply identifying the `right' model of choice ... More
Supersymmetric Extension of Hopf Maps: N=4 sigma-models and the S^3 -> S^2 FibrationDec 16 2009We discuss four off-shell N=4 D=1 supersymmetry transformations, their associated one-dimensional sigma-models and their mutual relations. They are given by I) the (4,4)_{lin} linear supermultiplet (supersymmetric extension of R^4), II) the (3,4,1)_{lin} ... More
Stochastic Depletion Problems: Effective Myopic Policies for a class of Dynamic Optimization ProblemsJan 24 2008This paper presents a general class of dynamic stochastic optimization problems we refer to as Stochastic Depletion Problems. A number of challenging dynamic optimization problems of practical interest are stochastic depletion problems. Optimal solutions ... More
Pound-Rebka experiment and torsion in the Schwarzschild spacetimeMar 14 2009Sep 02 2009We develop some ideas discussed by E. Schucking [arXiv:0803.4128] concerning the geometry of the gravitational field. First, we address the concept according to which the gravitational acceleration is a manifestation of the spacetime torsion, not of the ... More
On reference frames in spacetime and gravitational energy in freely falling framesApr 07 2007We consider the interpretation of tetrad fields as reference frames in spacetime. Reference frames may be characterized by an antisymmetric acceleration tensor, whose components are identified as the inertial accelerations of the frame (the translational ... More
The gravitational energy-momentum fluxJul 04 2003Aug 26 2003We present a continuity equation for the gravitational energy-momentum, which is obtained in the framework of the teleparallel equivalent of general relativity. From this equation it follows a general definition for the gravitational energy-momentum flux. ... More
Approximate Dynamic Programming via a Smoothed Linear ProgramAug 04 2009Oct 03 2009We present a novel linear program for the approximation of the dynamic programming cost-to-go function in high-dimensional stochastic control problems. LP approaches to approximate DP have typically relied on a natural `projection' of a well studied linear ... More
Topological self-dual configurations in a Lorentz-violating gauged O(3) sigma modelSep 14 2015Jan 11 2016We have studied the existence of topological Bogomol'nyi-Prasad-Sommerfield or self-dual configurations in a Lorentz-violating gauged $O(3)$ nonlinear sigma model, where $CPT$-even Lorentz-violating (LV) terms were introduced in both the gauge and $\sigma ... More
Tunable kinetic proofreading in a model with molecular frustrationSep 22 2011In complex systems, feedback loops can build intricate emergent phenomena, so that a description of the whole system cannot be easily derived from the properties of the individual parts. Here we propose that inter-molecular frustration mechanisms can ... More
Longitudinal dynamics with RF phase modulation in the LNLS electron storage ringOct 11 2006In the Brazilian synchrotron light source, we observed that modulating the phase of the accelerating fields at approximately twice the synchrotron frequency suppressed remarkably well a longitudinal coupled-bunch mode of the beam driven by a higher order ... More
Energy levels of triangular and hexagonal graphene quantum dots: a comparative study between the tight-binding and the Dirac approachNov 24 2011The Dirac equation is solved for triangular and hexagonal graphene quantum dots for different boundary conditions in the presence of a perpendicular magnetic field. We analyze the influence of the dot size and its geometry on their energy spectrum. A ... More
The split-operator technique for the study of spinorial wavepacket dynamicsJan 04 2016The split-operator technique for wave packet propagation in quantum systems is expanded here to the case of propagating wave functions describing Schr\"odinger particles, namely, charge carriers in semiconductor nanostructures within the effective mass ... More
(Giant) Vortex - (anti) vortex interaction in bulk superconductors: The Ginzburg-Landau theoryMay 25 2010The vortex-vortex interaction potential in bulk superconductors is calculated within the Ginzburg-Landau (GL) theory and is obtained from a numerical solution of a set of two coupled non-linear GL differential equations for the vector potential and the ... More
On the possibility of using seismic probes to study the core composition in pulsating white dwarfsNov 26 2012White dwarfs correspond to the final stages of stellar evolution of solar-type stars. In these objects, production of energy by nuclear burning has ended which means that a white dwarf simply cools down over the course of the next billion years. It is ... More
Two-component mixture of charged particles confined in a channel: meltingJun 09 2010The melting of a binary system of charged particles confined in a {\it quasi}-one-dimensional parabolic channel is studied through Monte Carlo simulations. At zero temperature the particles are ordered in parallel chains. The melting is anisotropic and ... More
On the effective potential for Horava-Lifshitz-like theories with the arbitrary critical exponentAug 16 2012Jan 11 2013We calculate the one-loop effective potential for Horava-Lifshitz-like QED and Yukawa-like theory for arbitrary values of the critical exponent and the space-time dimension.
The angular momentum of the gravitational field and the Poincare groupSep 06 2006We redefine the gravitational angular momentum in the framework of the teleparallel equivalent of general relativity. In similarity to the gravitational energy-momentum, the new definition for the gravitational angular momentum is coordinate independent. ... More
Tunable diffusion of magnetic particles in a quasi-one-dimensional channelSep 28 2012Jan 09 2013The diffusion of a system of ferromagnetic dipoles confined in a quasi-one-dimensional parabolic trap is studied using Brownian dynamics simulations. We show that the dynamics of the system is tunable by an in-plane external homogeneous magnetic field. ... More
Hysteresis and re-entrant melting of a self-organized system of classical particles confined in a parabolic trapJul 10 2007A self-organized system composed of classical particles confined in a two-dimensional parabolic trap and interacting through a potential with a short-range attractive part and long-range repulsive part is studied as function of temperature. The influence ... More
Positive solutions for non-variational fractional elliptic systems with negative exponentsMar 21 2019In this paper, we study strongly coupled elliptic systems in non-variational form with negative exponents involving fractional Laplace operators. We investigate the existence, nonexistence, and uniqueness of the positive classical solution. The results ... More
MOEA/D with Uniformly Randomly Adaptive WeightsAug 15 2019When working with decomposition-based algorithms, an appropriate set of weights might improve quality of the final solution. A set of uniformly distributed weights usually leads to well-distributed solutions on a Pareto front. However, there are two main ... More
Continuous variable quantum teleportation with non-Gaussian resourcesJun 25 2007We investigate continuous variable quantum teleportation using non-Gaussian states of the radiation field as entangled resources. We compare the performance of different classes of degaussified resources, including two-mode photon-added and two-mode photon-subtracted ... More
Low redshift constraints on energy-momentum-powered gravity modelsMay 07 2019There has been recent interest in the cosmological consequences of energy-momentum-powered gravity models, in which the matter side of Einstein's equations is modified by the addition of a term proportional to some power, $n$, of the energy-momentum tensor, ... More
Continuous variable quantum teleportation with sculptured and noisy non-Gaussian resourcesOct 17 2007Feb 27 2008We investigate continuous variable (CV) quantum teleportation using relevant classes of non-Gaussian states of the radiation field as entangled resources. First, we introduce the class two-mode squeezed symmetric superposition of Fock states, including ... More
SIGS - Seismic Inferences for Glitches in StarsMar 14 2017The increased amount of high precision seismic data for solar-like stars calls for the existence of tools that can extract information from such data. In the case of the study of acoustic glitches there are no publicly available tools and most existing ... More
On the superfield supersymmetric aether-like Lorentz-breaking modelsJun 20 2012Aug 07 2012Within the superfield approach, we formulate the superfield supersymmetric aether-like Lorentz-breaking models, both in three- and in four-dimensional cases.
Structure and correlations in two-dimensional Coulomb confined classical artificial atomsNov 01 2002The ordering of N equally charged particles (-e) moving in two dimensions and confined by a Coulomb potential, resulting from a displaced positive charge Ze is discussed. This is a classical model system for atoms. We obtain the configurations of the ... More
Topological confinement in graphene bilayer quantum ringsMar 17 2010We demonstrate the existence of localized electron and hole states in a ring-shaped potential kink in biased bilayer graphene. Within the continuum description, we show that for sharp potential steps the Dirac equation describing carrier states close ... More
Testing the AgreementMaker System in the Anatomy Task of OAEI 2012Dec 07 2012The AgreementMaker system was the leading system in the anatomy task of the Ontology Alignment Evaluation Initiative (OAEI) competition in 2011. While AgreementMaker did not compete in OAEI 2012, here we report on its performance in the 2012 anatomy task, ... More
Self-dual solitons in the restricted baby Skyrme model gauged with the Chern-Simons termJan 03 2019We have analyzed and verified the existence of self-dual solitons in a gauged baby Skyrme model whose gauge field is only ruled by the Chern-Simons action. We have consistently implemented the Bogomol'nyi-Prasad-Sommerfield formalism, obtaining a topological ... More
Braess paradox at the mesoscopic scaleNov 26 2013We theoretically demonstrate that the transport inefficiency recently found experimentally for branched-out mesoscopic networks can also be observed in a quantum ring of finite width with an attached central horizontal branch. This is done by investigating ... More
Interfering with decay of a single photon in microwave cavities through single photon quantum non-demolition schemeDec 07 2000May 01 2001The decay of a single photon in a microwave cavity is shown to be retarded by interaction with a resonant two-level atom in the experimental setup recently developed by Nogues and co-workers [see G. Nogues, A. Rauschenbeutel, S. Osnaghi, M. Brune, J. ... More
Gaussian deformations in graphene ribbons: flowers and confinementMay 08 2014Jul 04 2014The coupling of geometrical and electronic properties is a promising venue to engineer conduction properties in graphene. Confinement added to strain allows for interplay of different transport mechanisms with potential device applications. To investigate ... More
On the effective potential, Horava-Lifshitz-like theories and finite temperatureNov 25 2013Nov 27 2013We calculate the one-loop effective potential at finite temperature for the Horava-Lifshitz-like QED and Yukawa-like theories for arbitrary values of the critical exponent and the space-time dimension. Additional remarks on the zero temperature situation ... More
On the effective potential for Horava-Lifshitz-like theoriesDec 09 2011Jun 22 2012We study the one-loop effective potential for some Horava-Lifshitz-like theories.
Wave packet dynamics and valley filter in strained grapheneMay 05 2011The time evolution of a wavepacket in strained graphene is studied within the tight-binding model and continuum model. The effect of an external magnetic field, as well as a strain-induced pseudo-magnetic field, on the wave packet trajectories and zitterbewegung ... More
Universal Reinforcement LearningJul 20 2007Jul 22 2009We consider an agent interacting with an unmodeled environment. At each time, the agent makes an observation, takes an action, and incurs a cost. Its actions can influence future observations and costs. The goal is to minimize the long-term average cost. ... More
Self-dual solitons in a $CPT$-odd and Lorentz-violating gauged $O(3)$ sigma modelOct 03 2016We have performed a complete study of self-dual configurations in a $CPT$-odd and Lorentz-violating gauged $O(3)$ nonlinear sigma model. We have consistently implemented the Bogomol'nyi-Prasad-Sommerfield (BPS) formalism and obtained the correspondent ... More
Valley filtering using electrostatic potentials in bilayer grapheneJan 04 2016Propagation of an electron wave packet through a quantum point contact (QPC) defined by electrostatic gates in bilayer graphene is investigated. The gates provide a bias between the layers, in order to produce an energy gap. If the gates on both sides ... More
Chiral states in bilayer graphene: magnetic field dependence and gap openingSep 13 2011At the interface of electrostatic potential kink profiles one dimensional chiral states are found in bilayer graphene (BLG). Such structures can be created by applying an asymmetric potential to the upper and the lower layer of BLG. We found that: i) ... More
Electrostatically confined Quantum Rings in bilayer GrapheneAug 19 2009We propose a new system where electron and hole states are electrostatically confined into a quantum ring in bilayer graphene. These structures can be created by tuning the gap of the graphene bilayer using nanostructured gates or by position-dependent ... More
Snake states in graphene quantum dots in the presence of a p-n junctionJan 15 2013We investigate the magnetic interface states of graphene quantum dots that contain p-n junctions. Within a tight-binding approach, we consider rectangular quantum dots in the presence of a perpendicular magnetic field containing p-n, as well as p-n-p ... More
Polaron effects in electron channels on a helium filmApr 19 2001Using the Feynman path-integral formalism we study the polaron effects in quantum wires above a liquid helium film. The electron interacts with two-dimensional (2D) surface phonons, i.e. ripplons, and is confined in one dimension (1D) by an harmonic potential. ... More
Potential Energy Curves and Generalized Oscillator Strength for Doubly Excited States of Hydrogen MoleculeMar 30 2015In this paper we report calculations of potential energy curves in the $1.2 a.u.\le R\le100 a.u.$ range at Multireference Configuration Interaction (MRCI) level for doubly excited states of the H$_2$ molecule. We have focused on the $Q_2$ states which ... More
Structural Transitions in a Classical Two-Dimensional Molecule SystemMar 06 2002The ground state of a classical two-dimensional (2D) system with finite number of charged particles, trapped by two positive impurities charges localized at a distance (zo) from the 2D plane and separated from each other by a distance xp are obtained. ... More
Exciton trapping in magnetic wire structuresMar 16 2001The lateral magnetic confinement of quasi two-dimensional excitons into wire like structures is studied. Spin effects are take into account and two different magnetic field profiles are considered, which experimentally can be created by the deposition ... More
Fine structure of excitons in a quantum well in the presence of a nonhomogeneous magnetic fieldJun 06 2000Jun 14 2000The trapping of excitons in a semiconductor quantum well due to a circular symmetric nonhomogeneous magnetic field is studied. The effect of the spin state of the exciton on its trapping energy is analyzed, and the importance of the interaction of the ... More
Confinement of two-dimensional excitons in a non-homogeneous magnetic fieldOct 22 1999Feb 25 2000The effective Hamiltonian describing the motion of an exciton in an external non-homogeneous magnetic field is derived. The magnetic field plays the role of an effective potential for the exciton motion, results into an increment of the exciton mass and ... More
Yukawa particles confined in a channel and subject to a periodic potential: ground state and normal modesJun 10 2010We consider a classical system of two-dimensional (2D) charged particles, which interact through a repulsive Yukawa potential $exp(-r/\lambda)/r$, confined in a parabolic channel which limits the motion of the particles in the $y$-direction. Along the ... More
Wavepacket scattering on graphene edges in the presence of a (pseudo) magnetic fieldSep 13 2012The scattering of a Gaussian wavepacket in armchair and zigzag graphene edges is theoretically investigated by numerically solving the time dependent Schr\"odinger equation for the tight-binding model Hamiltonian. Our theory allows to investigate scattering ... More
All-strain based valley filter in graphene nanoribbons using snake statesJun 29 2016A pseudo-magnetic field kink can be realized along a graphene nanoribbon using strain engineering. Electron transport along this kink is governed by snake states that are characterized by a single propagation direction. Those pseudo-magnetic fields point ... More
Phases of quantum states in completely positive non-unitary evolutionMay 23 2002Jun 21 2003We define an operational notion of phases in interferometry for a quantum system undergoing a completely positive non-unitary evolution. This definition is based on the concepts of quantum measurement theory. The suitable generalization of the Pancharatnan ... More
Time Evolution of tunneling and decoherence: soluble modelApr 27 2001Decoherence effects associated to the damping of a tunneling two-level system are shown to dominate the tunneling probability at short times in strong coupling regimes in the context of a soluble model. A general decomposition of tunneling rates in dissipative ... More
Landau levels in asymmetric graphene trilayersJul 04 2011The electronic spectrum of three coupled graphene layers (graphene trilayers) is investigated in the presence of an external magnetic field. We obtain analytical expressions for the Landau level spectrum for both the ABA and ABC - type of stacking, which ... More
Simplified model for the energy levels of quantum rings in single layer and bilayer grapheneFeb 08 2010Within a minimal model, we present analytical expressions for the eigenstates and eigenvalues of carriers confined in quantum rings in monolayer and bilayer graphene. The calculations were performed in the context of the continuum model, by solving the ... More
Demonstrations of magnetic phenomena: Measuring the air permeablity using tabletsMay 26 2014We use a tablet to determine experimentally the dependencies of the magnetic field (B) on the electrical current and on the axial distance from a coil (z). Our data shows a good precision on the inverse cubic dependence of the magnetic field on the axial ... More
Self-dual solitons in a generalized Chern-Simons baby Skyrme modelJan 03 2019Feb 17 2019We have shown the existence of self-dual solitons in a type of generalized Chern-Simons baby Skyrme model where the generalized function (depending only in the Skyrme field) is coupled to the sigma-model term. The consistent implementation of the Bogomol'nyi-Prasad-Sommerfield ... More
Conditions for non-monotonic vortex interaction in two-band superconductorsMay 12 2011We describe a semi-analytic approach to the two-band Ginzburg-Landau theory, which predicts the behavior of vortices in two-band superconductors. We show that the character of the short-range vortex-vortex interaction is determined by the sign of the ... More
Sensitivity to Initial Conditions in Quantum Dynamics: an Analytical Semiclassical ExpansionJan 17 2002We construct a class of systems for which quantum dynamics can be expanded around a mean field approximation with essentially classical content. The modulus of the quantum overlap of mean field states naturally introduces a classical distance between ... More
Decoherence and localization in the double well modelApr 04 2005We use a spin-1/2 model to analyze tunnelling in a double well system coupled to an external reservoir. We consider different noise sources such as fluctuations on the height and central position of the barrier and propose an experiment to observe these ... More
Recovering the colour-dependent albedo of exoplanets with high-resolution spectroscopy: from ESPRESSO to the ELTMay 21 2018Aug 03 2018The characterization of planetary atmospheres is a daunting task, pushing current observing facilities to their limits. The next generation of high-resolution spectrographs mounted on large telescopes -- such as ESPRESSO@VLT and HIRES@ELT -- will allow ... More
Mechanism of vortices generation for a trapped superfluid under oscillatory excitationJul 05 2012The vortex nucleation and the emergence of quantum turbulence induced by oscillating magnetic fields, introduced by [1, 2], left a few open questions concerning the basic mechanisms causing those interesting phenomema. Here, we report the experimental ... More
Decoherence of mesoscopic states of cavity fieldsApr 14 1998We show that two-atom correlation measurements of the type involved in a recent experimental study of the evolution of a mesoscopic superposition state prepared in a definite mode of a high-Q cavity can be used to determine the eigenvalues of the reduced ... More
Structural and dynamical properties of a quasi-one-dimensional classical binary systemJun 09 2010The ground state configurations and the \lq{}\lq{}normal\rq{}\rq{} mode spectra of a $quasi$-one-dimensional (Q1D) binary system of charged particles interacting through a screened Coulomb potential are presented. The minimum energy configurations were ... More
Toward a test of angular momentum coherence in a twin-atom interferometerOct 20 2014Jun 24 2015We present a scheme well-suited to investigate quantitatively the angular momentum coherence of molecular fragments. Assuming that the dissociated molecule has a null total angular momentum, we investigate the propagation of the corresponding atomic fragments ... More
Out-of-phase oscillation between superfluid and thermal components for a trapped Bose condensate under oscillatory excitationJul 05 2012Jan 24 2019The vortex nucleation and the emergence of quantum turbulence induced by oscillating magnetic fields, introduced by Henn E A L, et al. 2009 (Phys. Rev. A 79, 043619) and Henn E A L, et al. 2009 (Phys. Rev. Lett. 103, 045301), left a few open questions ... More
Continuous Monitoring of Dynamical Systems and Master EquationsNov 04 2011May 06 2012We illustrate the equivalence between the non-unitary evolution of an open quantum system governed by a Markovian master equation and a process of continuous measurements involving this system. We investigate a system of two coupled modes, only one of ... More
Transition from single-file to two-dimensional diffusion of interacting particles in a quasi-one-dimensional channelOct 21 2010Mar 20 2012Diffusive properties of a monodisperse system of interacting particles confined to a \textit{quasi}-one-dimensional (Q1D) channel are studied using molecular dynamics (MD) simulations. We calculate numerically the mean-squared displacement (MSD) and investigate ... More
Robotic Tankette for Intelligent BioEnergy Agriculture: Design, Development and Field TestsJan 03 2019In recent years, the use of robots in agriculture has been increasing mainly due to the high demand of productivity, precision and efficiency, which follow the climate change effects and world population growth. Unlike conventional agriculture, sugarcane ... More
Experimental evidence of twin fast metastable H(2S) atoms from dissociation of cold H_2 induced by electronsJul 05 2013We report the direct detection of two metastable H(2S) atoms coming from the dissociation of a single cold H_2 molecule, in coincidence measurements. The molecular dissociation was induced by electron impact in order to avoid limitations by the selection ... More
Band structure derived properties of HfO2 from first principles calculationsApr 13 2012The electronic band structures and optical properties of cubic, tetragonal, and monoclinic phases of HfO2 are calculated using the first-principles linear augmented plane-wave method, within the density functional theory and generalized gradient approximation, ... More
The Nature and Origin of Substructure in the Outskirts of M31. I. Surveying the Stellar Content with HST/ACSMar 18 2008We present the largest and most detailed survey to date of the stellar populations in the outskirts of M31 based on the analysis of 14 deep HST/ACS pointings spanning the range 11.5-45.0 kpc. We conduct a quantitative comparison of the resolved stellar ... More
Effective masses and complex dielectric function of cubic HfO2Apr 13 2012The electronic band structure of cubic HfO2 is calculated using an it ab initio all-electron self--consistent linear augmented plane-wave method, within the framework of the local-density approximation and taking into account full-relativistic contributions. ... More
Stability and accuracy control of $\mathbf{k \cdot p}$ parametersAug 17 2016The $\mathbf{k \cdot p}$ method is a successful approach to obtain band structure, optical and transport properties of semiconductors, and it depends on external parameters that are obtained either from experiments, tight binding or ab initio calculations. ... More
Robustness of bipartite Gaussian entangled beams propagating in lossy channelsSep 22 2010Subtle quantum properties offer exciting new prospects in optical communications. Quantum entanglement enables the secure exchange of cryptographic keys and the distribution of quantum information by teleportation. Entangled bright beams of light attract ... More
Probing the Nature of the G1 Clump Stellar Overdensity in the Outskirts of M31Nov 28 2006We present deep HST/ACS observations of the G1 clump, a distinct stellar overdensity lying at ~30 kpc along the south-western major axis of M31 close to the G1 globular cluster (Ferguson et al. 2002). Our well-populated colour-magnitude diagram reaches ... More
Analyzing and characterizing political discussions in WhatsApp public groupsApr 02 2018We present a thorough characterization of what we believe to be the first significant analysis of the behavior of groups in WhatsApp in the scientific literature. Our characterization of over 270,000 messages and about 7,000 users spanning a 28-day period ... More
A photometric and spectroscopic study of the new dwarf spheroidal galaxy in HerculesAug 24 2009Our aim is to provide as clean and as complete a sample as possible of red giant branch stars that are members of the Hercules dSph galaxy. With this sample we explore the velocity dispersion and the metallicity of the system. Stromgren photometry and ... More
Disentanglement in Bipartite Continuous-Variable SystemsSep 22 2010Nov 17 2011Entanglement in bipartite continuous-variable systems is investigated in the presence of partial losses, such as those introduced by a realistic quantum communication channel, e.g. by propagation in an optical fiber. We find that entanglement can vanish ... More
Low Temperature Phase Transition in Sr(0.66)Ba(0.34)Nb2O6 single Crystal FibersAug 21 2001The structural changes in Sr(0.66)Ba(0.34)Nb2O6 single crystal fibers when the temperature decreases from 295 to 10 K is investigated by dielectric constant measurements and Raman spectroscopy. The anomaly observed in the plot of e is associated to the ... More