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Results for "Messina Vincenzina"

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Efficient Kernel-based Subsequence Search for User Identification from Walking ActivityJun 11 2019This paper presents an efficient approach for subsequence search in data streams. The problem consists in identifying coherent repetitions of a given reference time-series, eventually multi-variate, within a longer data stream. Dynamic Time Warping (DTW) ... More
Electrostatics in soft matterNov 27 2008Recent progress in the understanding of the effect of electrostatics in soft matter is presented. A vast amount of materials contains ions ranging from the molecular scale (e.g., electrolyte) to the meso/macroscopic one (e.g., charged colloidal particles ... More
Image charges in spherical geometry: Application to colloidal systemsApr 25 2002Jun 13 2002The effects of image charges (i.e., induced surface charges of polarization) in spherical geometry and their implication for charged colloidal systems are investigated. We study analytically and exactly a single microion interacting with a dielectric ... More
Spherical Colloids: Effect of Discrete Macroion Charge Distribution and Counterion ValenceApr 04 2001Apr 22 2002We report the coupled effects of macroion charge discretization and counterion valence in the primitive model for spherical colloids. Instead of considering a uniformly charged surface, as it is traditionally done, we consider a more realistic situation ... More
Macroion adsorption: The crucial role of excluded volume and coionsOct 17 2007The adsorption of charged colloids (macroions) onto an oppositely charged planar substrate is investigated theoretically. Taking properly into account the finite size of the macroions, unusual behaviors are reported. It is found that the role of the coions ... More
Latest Jet Results from TevatronMay 15 2006May 16 2006This contribution reports preliminary jet results in ppbar collisions at sqrt(s)=1.96 TeV from the CDF and D0 experiments. The jet inclusive cross section, measured using both the Midpoint and the K_T jet clustering algorithm, is compared to next-to-leading ... More
Evidence from stellar rotation for early disc dispersal owing to close companionsJun 13 2019Young low-mass stars of equal-mass exhibit a distribution of rotation periods. At the very early phases of stellar evolution, this distribution is set by the star-disc locking mechanism. The primordial disc lifetime and, consequently, the duration of ... More
Evidence from stellar rotation for early disc dispersal owing to close companionsJun 13 2019Jun 21 2019Young low-mass stars of equal-mass exhibit a distribution of rotation periods. At the very early phases of stellar evolution, this distribution is set by the star-disc locking mechanism. The primordial disc lifetime and, consequently, the duration of ... More
Long-term magnetic activity in close binary systems. I. Patterns of color variationsDec 13 2007We present the results of a long-term photometric monitoring project carried out at Catania Astrophysical Observatory and aimed at studying magnetic activity in close binary systems. We present the complete observations dataset (38,000 photoelectric observations ... More
Behavior of rod-like polyelectrolytes near an oppositely charged surfaceAug 02 2005Oct 19 2005The behavior of highly charged short rod-like polyelectrolytes near oppositely charged planar surfaces is investigated by means of Monte Carlo simulations. A detailed microstructural study, including monomer and fluid charge distribution, and chain orientation, ... More
W + Jet Production at CDFOct 17 2006Oct 20 2006The cross section for the inclusive production of W bosons in association with jets in ppbar collisions at sqrt(s)=1.96 TeV using the Collider Detector at Fermilab (CDF II) is presented. The measurement is based on an integrated luminosity of 320pb^-1, ... More
A single atom-based generation of Bell states of two cavitiesMar 28 2002A new conditional scheme for generating Bell states of two spatially separated high-Q cavities is reported. Our method is based on the passage of one atom only through the two cavities. A distinctive feature of our treatment is that it incorporates from ... More
SUSY contributions to the charge asymmetry in K^+- -> pi^+- l^+ l^- decaysFeb 25 2002We analyse the contributions to the charge asymmetry in $K^\pm\to\pi^\pm\ell^+\ell^-$ decays induced by gluino-exchange diagrams in the context of supersymmetric models with generic flavour couplings. We show that sizeable deviations with respect to the ... More
Behavior of block-polyampholytes near a charged surfaceAug 22 2006The behavior of polyampholytes near a charged planar surface is studied by means of Monte Carlo simulations. The investigated polyampholytes are overall electrically neutral and made up of oppositely charged units (called blocks) that are highly charged ... More
Adsorption of Oppositely Charged Polyelectrolytes onto a Charged RodJun 12 2003Jul 22 2003The adsorption of highly charged flexible polycations and polyanions on a charged cylindrical substrate is investigated by means of Monte Carlo (MC) simulations. A detailed structural study, including monomer and fluid charge distributions, is provided. ... More
Effect of Image Forces on Polyelectrolyte Adsorption at a Charged SurfaceJun 03 2004The adsorption of flexible and highly charged polyelectrolytes onto oppositely charged planar surfaces is investigated by means of Monte Carlo simulations. The effect of image forces stemming from the dielectric discontinuity at the substrate interface ... More
Polyelectrolyte Multilayering on a Charged Planar SurfaceMay 23 2003Oct 22 2003The adsorption of highly \textit{oppositely} charged flexible polyelectrolytes (PEs) on a charged planar substrate is investigated by means of Monte Carlo (MC) simulations. We study in detail the equilibrium structure of the first few PE layers. The influence ... More
Unitary transfer of entanglement in multipartite two-level systemsJun 05 2012The dynamics of a system composed by two pairs of dipolarly coupled two-level atoms is exactly studied. We show that the initial entanglement stored in a couple of atoms not directly interacting is fully transferred to the other pair in a periodic way. ... More
Scattering-matrix approach to Casimir-Lifshitz force and heat transfer out of thermal equilibrium between arbitrary bodiesAug 23 2011Oct 04 2011We study the radiative heat transfer and the Casimir-Lifshitz force occurring between two bodies in a system out of thermal equilibrium. We consider bodies of arbitrary shape and dielectric properties, held at two different temperatures, and immersed ... More
Casimir-Lifshitz force out of thermal equilibrium and heat transfer between arbitrary bodiesDec 23 2010Aug 23 2011We study the Casimir-Lifshitz force and the radiative heat transfer occurring between two arbitrary bodies, each one held at a given temperature, surrounded by environmental radiation at a third temperature. The system, in stationary configuration out ... More
Fluctuations of the Casimir-Polder force between an atom and a conducting wallJun 12 2007We consider the quantum fluctuations of the Casimir-Polder force between a neutral atom and a perfectly conducting wall in the ground state of the system. In order to obtain the atom-wall force fluctuation we first define an operator directly associated ... More
Relaxation back to equilibrium after cessation of shear for confined colloidal bilayersJun 24 2005Crystalline bilayers of charged colloidal suspensions which are confined between two parallel plates and sheared via a relative motion of the two plates are studied by extensive Brownian dynamics computer simulations. The charge-stabilized suspension ... More
Three-body radiative heat transfer and Casimir-Lifshitz force out of thermal equilibrium for arbitrary bodiesFeb 11 2014We study the Casimir-Lifshitz force and the radiative heat transfer in a system consisting of three bodies held at three independent temperatures and immersed in a thermal environment, the whole system being in a stationary configuration out of thermal ... More
Distilling angular momentum nonclassical states in trapped ionsMay 14 2004In the spirit of Quantum Non-Demolition Measurements, we show that exploiting suitable vibronic couplings and repeatedly measuring the atomic population of a confined ion, it is possible to distill center of mass vibrational states with well defined square ... More
N-qubit states as points on the Bloch sphereOct 04 2009Oct 01 2010We show how the Majorana representation can be used to express the pure states of an N-qubit system as points on the Bloch sphere. We compare this geometrical representation of N-qubit states with an alternative one, proposed recently by the present authors. ... More
On the estimation of the Lorenz curve under complex sampling designsDec 09 2018This paper focuses on the estimation of the concentration curve of a finite population, when data are collected according to a complex sampling design with different inclusion probabilities. A (design-based) Hajek type estimator for the Lorenz curve is ... More
Stability and UV completion of the Standard ModelJul 31 2015The knowledge of the stability condition of the electroweak (EW) vacuum is of the greatest importance for our understanding of beyond Standard Model (BSM) physics. It is widely believed that new physics that lives at very high energy scales should have ... More
Genuine Tripartite Entanglement in a Spin-Star Network at Thermal EquilibriumOct 08 2010Apr 14 2011In a recent paper [M. Huber {\it et al}, Phys. Rev. Lett. {\bf 104}, 210501 (2010)] new criteria to find out the presence of multipartite entanglement have been given. We exploit these tools in order to study thermal entanglement in a spin-star network ... More
Stability, Higgs Boson Mass and New PhysicsJul 19 2013May 27 2014When the particle with mass $\sim 126$ GeV discovered at LHC is identified with the Higgs boson of the Standard Model, intriguing and challenging questions arise. Among them, the issue of the EW vacuum stability. We find that, despite claims to the contrary, ... More
Manifold Mixup improves text recognition with CTC lossMar 11 2019Modern handwritten text recognition techniques employ deep recurrent neural networks. The use of these techniques is especially efficient when a large amount of annotated data is available for parameter estimation. Data augmentation can be used to enhance ... More
Reconstruction of Hamiltonians from given time evolutionsJun 27 2010Feb 27 2011In this paper we propose a systematic method to solve the inverse dynamical problem for a quantum system governed by the von Neumann equation: to find a class of Hamiltonians reproducing a prescribed time evolution of a pure or mixed state of the system. ... More
Reentrant transitions in colloidal or dusty plasma bilayersFeb 18 2003Aug 08 2003The phase diagram of crystalline bilayers of particles interacting via a Yukawa potential is calculated for arbitrary screening lengths and particle densities. Staggered rectangular, square, rhombic and triangular structures are found to be stable including ... More
Polynomial method to study the entanglement of pure N-qubit statesAug 12 2009Jan 12 2010We present a mapping which associates pure N-qubit states with a polynomial. The roots of the polynomial characterize the state completely. Using the properties of the polynomial we construct a way to determine the separability and the number of unentangled ... More
Self-Assembly of Magnetic Spheres in Strong Homogeneous Magnetic FieldFeb 02 2016The self-assembly in two dimensions of spherical magnets in strong magnetic field is addressed theoretically. %% It is shown that the attraction and assembly of parallel magnetic chains is the result of a delicate interplay of dipole-dipole interactions ... More
Casimir-Polder force density between an atom and a conducting wallNov 14 2006In this paper we calculate the Casimir-Polder force density (force per unit area acting on the elements of the surface) on a metallic plate placed in front of a neutral atom. To obtain the force density we use the quantum operator associated to the electromagnetic ... More
Unitary Representations of Quantum Superpositions of two Coherent States and beyondJun 11 2013Jun 12 2013The construction of a class of unitary operators generating linear superpositions of generalized coherent states from the ground state of a quantum harmonic oscillator is reported. Such a construction, based on the properties of a new ad hoc introduced ... More
Dynamical Behavior of a Squid Ring Coupled to a Quantized Electromagnetic FieldMar 26 2002In this paper we investigate the dynamical behavior of a SQUID ring coupled to a quantized single-mode electromagnetic field. We have calculated the eigenstates of the combined fully quantum mechanical SQUID-field system. Interesting phenomena occur when ... More
Quantum superpositions of clockwise and counterclockwise supercurrent states in the dynamics of a rf-SQUID exposed to a quantized electromagnetic fieldNov 11 2002Nov 15 2002The dynamical behavior of a superconducting quantum interference device (a rf-SQUID) irradiated by a single mode quantized electromagnetic field is theoretically investigated. Treating the SQUID as a flux qubit, we analyze the dynamics of the combined ... More
Dynamic Work Distribution for PM AlgorithmMay 25 2000Although poor for small dynamic scales, the Particle-Mesh (PM) model allows in astrophysics good insight for large dynamic scales at low computational cost. Furthermore, it is possible to employ a very high number of particles to get high mass resolution. ... More
Graphene-based photovoltaic cells for near-field thermal energy conversionJul 05 2012Thermophotovoltaic devices are energy-conversion systems generating an electric current from the thermal photons radiated by a hot body. In far field, the efficiency of these systems is limited by the thermodynamic Schockley-Queisser limit corresponding ... More
Riccati equation-based generalization of Dawson's integral functionJun 15 2007A new generalization of Dawson's integral function based on the link between a Riccati nonlinear differential equation and a second-order ordinary differential equation is reported. The MacLaurin expansion of this generalized function is built up and ... More
Entanglement swapping in a Franson interferometer setupJun 18 2007Oct 03 2007We propose a simple scheme to swap the non local correlations, characteristic of a Franson interferometric setup, between pairs of frequency entangled photons emitted by distinct non linear crystals in a parametric down conversion process. Our scheme ... More
Ultrafast Large Angle Beamstrahlung MonitorMar 26 2017The analysis of beamstrahlung radiation, emitted from a beam of charged particles due to the electromagnetic interaction with a second beam of charged particles, provides a diagnostic tool that can be used to monitor beam-beam collisions in a $e^{+}e^{-}$ ... More
Exact treatment of operator difference equations with nonconstant noncommutative coefficientsJun 26 2012Dec 11 2012In this paper we study in a Hilbert space a homogeneous linear second order difference equation with nonconstant and noncommuting operator coefficients. We build its exact resolutive formula consisting in the explicit non-iterative expression of a generic ... More
Three-body amplification of photon heat tunnelingMay 09 2012Resonant tunneling of surface polaritons across a subwavelength vacuum gap between two polar or metallic bodies at different temperatures leads to an almost monochromatic heat transfer which can exceed by several orders of magnitude the far-field upper ... More
Monte Carlo simulation of abnormal grain growth in two dimensionsNov 29 2000Abnormal grain growth in the presence of second phase particles is investigated with the help of a two-dimensional Monte Carlo simulation. An aggregate of equiaxed grains is considered with constant grain boundary energy and mobility. The only driving ... More
Scan, Attend and Read: End-to-End Handwritten Paragraph Recognition with MDLSTM AttentionApr 12 2016Aug 23 2016We present an attention-based model for end-to-end handwriting recognition. Our system does not require any segmentation of the input paragraph. The model is inspired by the differentiable attention models presented recently for speech recognition, image ... More
PT-symmetric $\varphi^4$ theory in d=0 dimensionsJan 02 2015A detailed study of a PT-symmetric zero-dimensional quartic theory is presented and a comparison between the properties of this theory and those of a conventional quartic theory is given. It is shown that the PT-symmetric quartic theory evades the consequences ... More
Polyelectrolyte Multilayering on a Charged SphereDec 12 2002Jun 16 2003The adsorption of highly \textit{oppositely} charged flexible polyelectrolytes onto a charged spherical surface is investigated by means of Monte Carlo simulations in a fashion which resembles the layer-by-layer deposition technique introduced by Decher. ... More
Strong electrostatic interactions in spherical colloidal systemsJan 17 2001Apr 26 2001We investigate spherical macroions in the strong Coulomb coupling regime within the primitive model in salt-free environment. We first show that the ground state of an isolated colloid is naturally overcharged by simple electrostatic arguments illustrated ... More
Effect of colloidal charge discretization in the primitive modelJun 30 2000Dec 21 2000The effect of fixed discrete colloidal charges in the primitive model is investigated for spherical macroions. Instead of considering a central bare charge, as it is traditionally done, we distribute \textit{discrete} charges randomly on the sphere. We ... More
Strong Attraction between Charged Spheres due to Metastable Ionized StatesJun 30 2000Dec 04 2000We report a mechanism which can lead to long range attractions between like-charged spherical macroions, stemming from the existence of metastable ionized states. We show that the ground state of a single highly charged colloid plus a few excess counterions ... More
A compared analysis of the susceptibility in the O(N) theoryApr 12 2013The longitudinal susceptibility $\chi_L$ of the O(N) theory in the broken phase is analyzed by means of three different approaches, namely the leading contribution of the 1/N expansion, the Functional Renormalization Group flow in the Local Potential ... More
Geometric phase accumulation-based effects in the quantum dynamics of an anisotropically trapped ionSep 25 2004Mar 31 2005New physical effects in the dynamics of an ion confined in an anisotropic two-dimensional Paul trap are reported. The link between the occurrence of such manifestations and the accumulation of geometric phase stemming from the intrinsic or controlled ... More
Realization of a space reversal operatorMay 13 2002In this paper we propose the realization of a bosonic-fermionic interaction in the context of trapped ions whose effect upon the ion center of mass degrees of freedom is properly speaking a spatial inversion. The physical system and its features are accurately ... More
Quantum Zeno Subspaces induced by TemperatureJun 11 2011We discuss the partitioning of the Hilbert space of a quantum system induced by the interaction with another system at thermal equilibrium, showing that the higher the temperature the more effective is the formation of Zeno subspaces. We show that our ... More
Dissipation and entanglement dynamics for two interacting qubits coupled to independent reservoirsJun 30 2008We derive the master equation of a system of two coupled qubits by taking into account their interaction with two independent bosonic baths. Important features of the dynamics are brought to light, such as the structure of the stationary state at general ... More
Perturbative Treatment of the Evolution Operator Associated with Raman CouplingsMay 10 2006A novel perturbative treatment of the time evolution operator of a quantum system is applied to the model describing a Raman-driven trapped ion in order to obtain a suitable 'effective model'. It is shown that the associated effective Hamiltonian describes ... More
New exactly solvable relativistic models with anomalous interactionSep 30 2009May 06 2011A special class of Dirac-Pauli equations with time-like vector potentials of external field is investigated. A new exactly solvable relativistic model describing anomalous interaction of a neutral Dirac fermion with a cylindrically symmetric external ... More
Low Energy Antineutrino Detection Using Neutrino Capture on EC Decaying NucleiMar 06 2009In this paper we present a study of the interaction of low energy electron antineutrino on nuclei that undergo electron capture. We show that the two corresponding crossed reactions have a sizeable cross section and are both suitable for detection of ... More
Exact formulas for radiative heat transfer between planar bodies under arbitrary temperature profiles: modified asymptotics and sign-flip transitionsSep 01 2016Nov 29 2016We derive exact analytical formulas for the radiative heat transfer between parallel slabs separated by vacuum and subject to arbitrary temperature profiles. We show that, depending on the derivatives of the temperature at points close to the slab--vacuum ... More
Detection of Noble Gas Scintillation Light with Large Area Avalanche Photodiodes (LAAPDs)Dec 23 2004Large Area Avalanche Photodiodes (LAAPDs) were used for a series of systematic measurements of the scintillation light in Ar, Kr, and Xe gas. Absolute quantum efficiencies are derived. Values for Xe and Kr are consistent with those given by the manufacturer. ... More
Steering Distillation by "Pulsed" and "Continuous" MeasurementsApr 09 2004May 14 2004A new systematic strategy for steering the distillation process for a quantum system, that utilizes the so-called "pulsed" and "continuous" measurements on another quantum system in interaction with the former, is proposed. The distillation process characterized ... More
Coupling-assisted Landau-Majorana-Stuckelberg-Zener transition in two-interacting-qubit systemsDec 16 2018We analyse a system of two interacting spin-qubits subjected to a Landau-Majorana-Stuckelberg-Zener ramp. We show that a LMSZ transitions of the two spin-qubits are possible without an external transverse static field since its role is played by the coupling ... More
Exactly solvable time-dependent models of two interacting two-level systemsApr 15 2016Two coupled two-level systems placed under external time-dependent magnetic fields are modeled by a general Hamiltonian endowed with a symmetry that enables us to reduce the total dynamics into two independent two-dimensional sub-dynamics. Each of the ... More
Quantum Phase Transitions and Heat Capacity in a two-atoms Bose-Hubbard ModelJul 08 2011We show that a two-atoms Bose-Hubbard model exhibits three different phases in the behavior of thermal entanglement in its parameter space. These phases are demonstrated to be traceable back to the existence of quantum phase transitions in the same system. ... More
Density matrix operatorial solution of the non--Markovian Master Equation for Quantum Brownian MotionNov 29 2002An original method to exactly solve the non-Markovian Master Equation describing the interaction of a single harmonic oscillator with a quantum environment in the weak coupling limit is reported. By using a superoperatorial approach we succeed in deriving ... More
The rotating wave system-reservoir coupling: limitations and meaning in the non-Markovian regimeDec 02 2002This paper deals with the dissipative dynamics of a quantum harmonic oscillator interacting with a bosonic reservoir. The Master Equations based on the Rotating Wave and on the Feynman-Vernon system--reservoir couplings are compared highlighting differences ... More
Interaction of bimodal fields with few-level atoms in cavities and trapsJun 21 2002The spectacular experimental results of the last few years in cavity quantum electrodynamics and trapped ions research has led to very high level laboratory performances. Such a stimulating situation essentially stems from two decisive advancements. The ... More
A possible time dependent generalization of the bipartite quantum marginal problemNov 05 2018In this work we study an inverse dynamical problem for a bipartite quantum system governed by the time local master equation: to find the class of generators which give rise to a certain time evolution with the constraint of fixed reduced states (marginals). ... More
Factorization and resummation: A new paradigm to improve gravitational wave amplitudes. II: the higher multipolar modesJan 08 2018The factorization and resummation approach of Nagar and Shah~[Phys.~Rev.~D~94 (2016), 104017], designed to improve the strong-field behavior of the post-Newtonian (PN) residual waveform amplitudes $f_{\ell m}$'s entering the effective-one-body, circularized, ... More
Crystalline multilayers of the confined Yukawa systemNov 28 2008Mar 18 2009The phase diagram of Yukawa particles confined between two parallel hard walls is calculated at zero-temperature beyond the bilayer regime by lattice-sum-minimization. Tuning the screening, a rich phase behavior is found in the regime bounded by stable ... More
Capturing Relic Neutrinos with beta-decaying nucleiNov 12 2007We summarize a novel approach which has been recently proposed for direct detection of low energy neutrino backgrounds such as the cosmological relic neutrinos, exploiting neutrino/antineutrino capture on nuclei that spontaneously undergo beta decay.
General formulation of coupled radiative and conductive heat transfer between compact bodiesMay 18 2016Sep 21 2016We present a general framework for studying strongly coupled radiative and conductive heat transfer between arbitrarily shaped bodies separated by sub-wavelength distances. Our formulation is based on a macroscopic approach that couples our recent fluctuating ... More
Charge inversion in colloidal systemsJan 08 2002We investigate spherical macroions in the strong Coulomb coupling regime within the primitive model in salt-free environment. Molecular dynamics (MD) simulations are used to elucidate the effect of $discrete$ macroion charge distribution on charge inversion. ... More
Conformation of a Polyelectrolyte Complexed to a Like-Charged ColloidNov 19 2001We report results from a molecular dynamics (MD) simulation on the conformations of a long flexible polyelectrolyte complexed to a charged sphere, \textit{both negatively charged}, in the presence of neutralizing counterions in the strong Coulomb coupling ... More
Zeno Dynamics and High-Temperature Master Equations Beyond Secular ApproximationJul 16 2013Oct 16 2013Complete positivity of a class of maps generated by master equations derived beyond the secular approximation is discussed. The connection between such class of evolutions and physical properties of the system is analyzed in depth. It is also shown that ... More
Landau-Majorana-Stuckelberg-Zener dynamics driven by coupling for two interacting qutrit systemsJan 02 2019A time-dependent two interacting spin-qutrit model is analysed and solved. The two interacting qutrits are subjected to a longitudinal field linearly varying over time as in the Landau-Majorana-Stuckelberg-Zener (LMSZ) scenario. Although a transverse ... More
Unitary decoupling treatment of a quadratic bimodal CQED modelDec 11 2012Dec 18 2012We consider a two-photon quantum model of radiation-matter interaction between a single two-level atom and a degenerate bimodal high-Q cavity field. Within this tripartite system the explicit construction of two collective radiation modes, one of which ... More
Interpreting concurrence in terms of covariances in a generalized spin star systemJun 20 2006The quantum dynamics of M pairwise coupled spin 1/2 is analyzed and the time evolution of the entanglement get established within a prefixed couple of spins is studied. A conceptual and quantitative link between the concurrence function and measurable ... More
Quantum Zeno Effect in Trapped IonsFeb 26 2001A "continuous measurement" Quantum Zeno Effect (QZE) in the context of trapped ions is predicted. We describe the physical system and study its exact time evolution showing the appearance of Zeno Phenomena. New indicators for the occurrence of QZE in ... More
Multilayered crystals of macroions under slit-confinementApr 21 2009Dec 23 2009The crystalline ground state of macroions confined between two neutral parallel plates in the presence of their homogeneously spread counterions is calculated by lattice-sum minimization of candidate phases involving up to six layers. For increasing macroion ... More
Impact of photometric variability on age and mass determination of Young Stellar Objects: A case study on Orion Nebula ClusterFeb 06 2017In case of pre-main sequence objects, the only way to determine age and mass is by fitting theoretical isochrones on color-magnitude (alternatively luminosity-temperature) diagrams. Since young stellar objects exhibit photometric variability over wide ... More
Unitary reduction of the Liouville equation relative to a two-level atom coupled to a bimodal lossy cavityNov 05 2002The Liouville equation of a two-level atom coupled to a degenerate bimodal lossy cavity is unitarily and exactly reduced to two uncoupled Liouville equations. The first one describes a dissipative Jaynes-Cummings model and the other one a damped harmonic ... More
Statistics of polymer adsorption under shear flowOct 09 2009Using non-equilibrium Brownian dynamics computer simulations, we have investigated the steady state statistics of a polymer chain under three different shear environments: i) linear shear flow in the bulk (no walls), ii) shear vorticity normal to the ... More
Elementary symmetric functions of two solvents of a quadratic matrix equationApr 18 2008Quadratic matrix equations occur in a variety of applications. In this paper we introduce new permutationally invariant functions of two solvents of the n quadratic matrix equation X^2- L1X - L0 = 0, playing the role of the two elementary symmetric functions ... More
Near-field refrigeration and tunable heat exchange through four-wave mixingDec 08 2017May 29 2018We modify and extend a recently proposed four-wave mixing scheme [Opt. Express 25 (19),23164 (2017)] for achieving near-field thermal upconversion and energy transfer, to demonstrate efficient thermal refrigeration at low intensities $\sim 10^{-9}$W/m$^2$ ... More
Ordinary versus PT-symmetric $φ^3$ quantum field theoryJan 05 2012A quantum-mechanical theory is PT-symmetric if it is described by a Hamiltonian that commutes with PT, where the operator P performs space reflection and the operator T performs time reversal. A PT-symmetric Hamiltonian often has a parametric region of ... More
Dynamics of an elementary quantum system in environments out of thermal equilibriumMay 30 2012Dec 07 2012We study the internal dynamics of an elementary quantum system placed close to a body held at a temperature different from that of the surrounding radiation. We derive general expressions for lifetime and density matrix valid for bodies of arbitrary geometry ... More
Dynamical Casimir-Polder force on a partially dressed atom near a conducting wallOct 29 2010Nov 12 2010We study the time evolution of the Casimir-Polder force acting on a neutral atom in front of a perfectly conducting plate, when the system starts its unitary evolution from a partially dressed state. We solve the Heisenberg equations for both atomic and ... More
Time-dependent Maxwell field operators and field energy density for an atom near a conducting wallMar 18 2009We consider the time evolution of the electric and magnetic field operators for a two-level atom, interacting with the electromagnetic field, placed near an infinite perfectly conducting wall. We solve iteratively the Heisenberg equations for the field ... More
Adversarial Generation of Handwritten Text Images Conditioned on SequencesMar 01 2019State-of-the-art offline handwriting text recognition systems tend to use neural networks and therefore require a large amount of annotated data to be trained. In order to partially satisfy this requirement, we propose a system based on Generative Adversarial ... More
The lifetime of the electroweak vacuum and sensitivity to Planck scale physicsAug 22 2014If the Standard Model (SM) is valid up to extremely high energy scales, then the Higgs potential becomes unstable at approximately $10^{11}$ GeV. However, calculations of the lifetime of the SM vacuum have shown that it vastly exceeds the age of the Universe. ... More
Thermally-activated non-local amplification in quantum energy transportMay 13 2015Nov 18 2015We study energy-transport efficiency in light-harvesting planar and 3D complexes of two-level atomic quantum systems, embedded in a common thermal blackbody radiation. We show that the collective non-local dissipation induced by the thermal bath plays ... More
Like-Charge Colloid-Polyelectrolyte ComplexationJan 28 2002We investigate the complexation of a highly charged sphere with a long flexible polyelectrolyte, \textit{both negatively charged} in salt free environment. Electroneutrality is insured by the presence of divalent counterions. Using molecular dynamics ... More
Ground state of two unlike charged colloids: An analogy with ionic bondingJun 30 2000Sep 12 2001In this letter, we study the ground state of two spherical macroions of identical radius, but asymmetric bare charge ((Q_{A}>Q_{B})). Electroneutrality of the system is insured by the presence of the surrounding divalent counterions. Using Molecular Dynamics ... More
Resonant transitions due to changing boundariesJan 10 2015Apr 19 2019The problem of a particle confined in a box with moving walls is studied, focusing on the case of small perturbations which do not alter the shape of the boundary (\lq pantography\rq). The presence of resonant transitions involving the natural transition ... More
An algebraic approach to the study of multipartite entanglementApr 10 2012Dec 11 2012A simple algebraic approach to the study of multipartite entanglement for pure states is introduced together with a class of suitable functionals able to detect entanglement. On this basis, some known results are reproduced. Indeed, by investigating the ... More
Coarse grained and fine dynamics in trapped ion Raman schemesOct 27 2003Nov 03 2003A novel result concerning Raman coupling schemes in the context of trapped ions is obtained. By means of an operator perturbative approach, it is shown that the complete time evolution of these systems (in the interaction picture) can be expressed, with ... More