Results for "J. Osvaldo Gonzalez-Hernandez"

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Flexible Parametrization of Generalized Parton Distributions from Deeply Virtual Compton Scattering ObservablesDec 16 2010Feb 16 2011We present a physically motivated parametrization of the chiral-even generalized parton distributions in the non-singlet sector obtained from a global analysis using a set of available experimental data. Our analysis is valid in the kinematical region ... More
Observations of Chiral Odd GPDs and their ImplicationsSep 28 2013Our original suggestion to investigate exclusive $\pi^0$ electroproduction as a method for extracting the tensor charge, transversity, and other quantities related to chiral odd generalized parton distributions from cross section and asymmetry data is ... More
Flavor dependence of chiral odd generalized parton distributions and the tensor charge from the analysis of combined $π^0$ and $η$ exclusive electroproduction dataJan 02 2014Using a physically motivated parameterization based on the reggeized diquark model we perform a flavor separation of the chiral-odd generalized parton distributions obtained from both $\pi^0$ and $\eta$ exclusive electroproduction. In our approach we ... More
Easy as $π^o$: On the Interpretation of Recent Electroproduction ResultsJan 29 2012Jul 02 2012Exclusive $\pi^o$ electroproduction from nucleons was first suggested by Ahmad, Goldstein and Liuti for extracting from experimental data the tensor charge, transversity and other quantities related to chiral odd combinations of generalized parton distributions. ... More
Partonic Picture of Generalized Transverse Momentum DistributionsSep 26 2013We argue that due to parity constraints, the helicity combination of the purely momentum space counterparts of the Wigner distributions -- the generalized transverse momentum distributions -- that describes the configuration of an unpolarized quark in ... More
Interpretation of the Flavor Dependence of Nucleon Form Factors in a Generalized Parton Distribution ModelJun 08 2012Sep 26 2013We give an interpretation of the $u$ and $d$ quarks contributions to the nucleon electromagnetic form factors for values of the four-momentum transfer in the multi-GeV region where flavor separated data have been recently made available. The data show, ... More
Identification of Observables for Quark and Gluon Orbital Angular MomentumDec 01 2014A new debate has recently arisen on the subject of orbital angular momentum in QCD, in particular on its observability and on its partonic interpretation. Orbital momentum can be defined in QCD using two different decomposition schemes that yield a kinetic ... More
On the Observability of the Quark Orbital Angular Momentum DistributionOct 18 2013Mar 18 2014We argue that due to Parity constraints, the helicity combination of the purely momentum space counterparts of the Wigner distributions -- the generalized transverse momentum distributions -- that describes the configuration of an unpolarized quark in ... More
Extraction of Generalized Parton Distribution Observables from Deeply Virtual Electron Proton Scattering ExperimentsMar 13 2019We provide the general expression of the cross section for exclusive deeply virtual photon electroproduction from a spin 1/2 target using current parameterizations of the off-forward correlation function in a nucleon for different beam and target polarization ... More
Deeply Virtual Neutrino Production of $π^0$ from Nucleon and Nuclear TargetsNov 02 2009In most experiments aimed at determining the masses and mixing parameters for neutrino oscillations in different energy regimes there are strong backgrounds to neutrino interactions with matter that can confuse the expected small signals. One particular ... More
Doppler tomography of the black hole binary A0620-00 and the origin of chromospheric emission in quiescent X-ray binariesApr 03 2010Doppler tomography of emission line profiles in low mass X-ray binaries allows us to disentangle the different emission sites and study the structure and variability of accretion disks. We present UVES high-resolution spectroscopic observations of the ... More
Surfaces in $mathbb{R}^4$ with constant principal angles with respect to a planeMay 09 2011We study surfaces in $\R^4$ whose tangent spaces have constant principal angles with respect to a plane. Using a PDE we prove the existence of surfaces with arbitrary constant principal angles. The existence of such surfaces turns out to be equivalent ... More
On the mass of the neutron star in Cyg X-2Oct 23 2009We present new high resolution spectroscopy of the low mass X-ray binary Cyg X-2 which enables us to refine the orbital solution and rotational broadening of the donor star. In contrast with Elebert et al (2009) we find a good agreement with results reported ... More
Chemically tagging the Hyades Supercluster: A homogeneous sample of F6-K4 kinematically selected northern starsMay 22 2012Stellar kinematic groups are kinematical coherent groups of stars that might have a common origin. These groups are dispersed throughout the Galaxy over time by the tidal effects of both Galactic rotation and disc heating, although their chemical content ... More
Chemical Tagging of FGK Stars: Testing Membership to Young Stellar Kinematics GroupsSep 11 2015In this contribution talk we summarize the results of our ongoing project of detailed analysis of the chemical content (chemical tagging) as a promising powerful method to provide clear constraints on the membership of FGK kinematic candidates to stellar ... More
On the Jacobi-Metric Stability CriterionMay 30 2007We investigate the exact relation existing between the stability equation for the solutions of a mechanical system and the geodesic deviation equation of the associated geodesic problem in the Jacobi metric constructed via the Maupertuis-Jacobi Principle. ... More
A phenomenological analysis of azimuthal asymmetries in unpolarized semi-inclusive deep inelastic scatteringFeb 14 2015Apr 03 2015We present a phenomenological analysis of the cos-phi and cos-2phi asymmetries in unpolarized semi-inclusive deep inelastic scattering, based on the recent multidimensional data released by the COMPASS and HERMES Collaborations. In the TMD framework, ... More
The Black Hole Binary Nova Scorpii 1994 (GRO J1655-40): An improved chemical analysisMay 18 2007Mar 10 2009The chemical analysis of secondary stars of low mass X-ray binaries provides an opportunity to study the formation processes of compact objects, either black holes or neutron stars. Following the discovery of overabundances of $\alpha$-elements in the ... More
Flexible Parametrization of Generalized Parton Distributions: The Chiral-Odd SectorNov 03 2013Dec 04 2014We present a physically motivated parameterization of the chiral-odd generalized parton distributions. The parametrization is an extension of our previous one in the chiral-even sector which was based on the reggeized diquark model. While for chiral even ... More
Quest for the Donor Star in the Magnetic Precataclysmic Variable V1082 SgrNov 20 2018We obtained high-resolution spectra and multicolor photometry of V1082 Sgr to study the donor star in this 20.8 hr orbital period binary, which is assumed to be a detached system. We measured the rotational velocity (v sin i = 26.5+/-2.0 km/s), which, ... More
Green's functions for far-side seismic images: a polar expansion approachMar 04 2010We have computed seismic images of magnetic activity on the far surface of the Sun by using a seismic-holography technique. As in previous works, the method is based on the comparison of waves going in and out of a particular point in the Sun but we have ... More
Temperature profile of an assemblage of non-isothermic linear energy convertersApr 16 2019In this paper, a proposal is presented to determine the temperature profile obtained for an assemblage of non-isothermal linear energy converters (ANLEC) published by Jimenez de Cisneros and Calvo Hernandez [1,2]. This is done without solving the Riccati's ... More
An unsupervised and customizable misspelling generator for mining noisy health-related text sourcesJun 04 2018In this paper, we present a customizable datacentric system that automatically generates common misspellings for complex health-related terms. The spelling variant generator relies on a dense vector model learned from large unlabeled text, which is used ... More
Global Potential Energy Minima of (H$_{2}$O)$_{n}$ Clusters on GraphiteJun 08 2007Likely candidates for the global potential energy minima of (H$_{2}$O)$_{n}$ clusters with $n\leq21$ on the (0001)-surface of graphite are found using basin-hopping global optimization. The potential energy surfaces are constructed using the TIP4P intermolecular ... More
A search for interstellar anthracene toward the Perseus anomalous microwave emission regionMay 24 2010We report the discovery of a new broad interstellar (or circumstellar) band at 7088.8 +- 2.0 \AA coincident to within the measurement uncertainties with the strongest band of the anthracene cation (C$_{14}$H$_{10}$$^+$) as measured in gas-phase laboratory ... More
Kinematics of Current Region Fragmentation in Semi-Inclusive Deeply Inelastic ScatteringNov 30 2016Jan 30 2017Different kinematical regimes of semi-inclusive deeply inelastic scattering (SIDIS) processes correspond to different underlying partonic pictures, and it is important to understand the transition between them. This is particularly the case when there ... More
Challenges with Large Transverse Momentum in Semi-Inclusive Deeply Inelastic ScatteringAug 13 2018Dec 12 2018We survey the current phenomenological status of semi-inclusive deep inelastic scattering at moderate hard scales and in the limit of very large transverse momentum. As the transverse momentum becomes comparable to or larger than the overall hard scale, ... More
Extremely metal-poor stars from the SDSSSep 17 2008We give a progress report about the activities within the CIFIST Team related to the search for extremely metal-poor stars in the Sloan Digital Sky Survey's spectroscopic catalog. So far the search has provided 25 candidates with metallicities around ... More
Phase-field models in interfacial pattern formation out of equilibriumMay 03 2003The phase-field method is reviewed from the general perspective of converting a free boundary problem into a set of coupled partial differential equations. Its main advantage is that it avoids front tracking by using phase fields to locate the fronts. ... More
Sidebranching induced by external noise in solutal dendritic growthJan 23 2001We have studied sidebranching induced by fluctuations in dendritic growth. The amplitude of sidebranching induced by internal (equilibrium) concentration fluctuations in the case of solidification with solutal diffusion is computed. This amplitude turns ... More
Chemical tagging of the Ursa Major moving group: A northern selection of FGK starsSep 08 2014Stellar kinematic groups are kinematical coherent groups of stars which might share a common origin.These groups spread through the Galaxy over time due to tidal effects caused by Galactic rotation and disc heating.However, the chemical information survives ... More
Detailed analyses of three neutron-capture-rich carbon-enhanced metal-poor starsSep 01 2009Approximately 20% of very metal-poor stars ([Fe/H] < -2.0) are strongly enhanced in carbon ([C/Fe] > +1.0). Such stars are referred to as carbon-enhanced metal-poor (CEMP) stars. We present a chemical abundance analysis based on high resolution spectra ... More
Large Transverse Momentum in Semi-Inclusive Deeply Inelastic Scattering Beyond Lowest OrderMar 04 2019Motivated by recently observed tension between $O\left(\alpha_s^2\right)$ calculations of very large transverse momentum dependence in both semi-inclusive deep inelastic scattering and Drell-Yan scattering, we repeat the details of the calculation through ... More
On explicit inversion of a subclass of operators with $D$-difference kernels and Weyl theory of the corresponding canonical systemsMay 11 2009Explicit inversion formulas for a subclass of integral operators with $D$-difference kernels on a finite interval are obtained. A case of the positive operators is treated in greater detail. An application to the inverse problem to recover canonical system ... More
Low X-ray Luminosity Galaxy Clusters. III: Weak Lensing Mass Determination at 0.18 $<$ z $<$ 0.70Apr 13 2015Apr 15 2015This is the third of a series of papers of low X-ray luminosity galaxy clusters. In this work we present the weak lensing analysis of eight clusters, based on observations obtained with the Gemini Multi-Object Spectrograph in the $g'$, $r'$ and $i'$ passbands. ... More
3D strain in 2D materials: Experimental test in unsupported monolayer graphene under pressureFeb 07 2019Previous Raman measurements on supported graphene under high pressure reported a very different shift rate of in-plane phonon frequency of graphene (16 cm$^{-1}$GPa$^{-1}$) from graphite (4.7 cm$^{-1}$GPa$^{-1}$), implying very different in-plane anharmonicity ... More
Diamond-Like Carbon Coatings on Plasma Nitrided M2 Steel: effect of deposition parameters on adhesion propertiesOct 12 2018Diamond-like carbon (DLC) coatings have excellent mechanical and tribological properties, as well as good wear and corrosion resistance. They are well established in medical, metalworking and automotive applications. However, further improvements are ... More
Effect of thermal treatments in high purity Ar on the oxidation behavior of arc-PVD c-Al0.66Ti0.33N coatingsOct 11 2018Jan 25 2019The effect of temperature in high purity Ar (low oxygen partial pressure) on the oxidation and crystal phase evolution of c-Al0.66Ti0.33N arc-PVD coatings was investigated. High temperature tribology in Ar jet and adhesion behavior of the oxidized coating ... More
Optimal execution of Portfolio transactions with geometric price processAug 10 2009Nov 25 2009In this paper we derive the optimal execution trajectory for a trader who wishes to buy or sell a large position of shares which evolve as a geometric Brownian process in contrast to the arithmetic model which prevails in the existing literature, and ... More
Flare activity and photospheric analysis of Proxima CentauriJun 14 2017We present the analysis of emission lines in high-resolution optical spectra of the planet-host star Proxima Centauri (Proxima) classified as a M5.5V\@. We carry out the detailed analysis of observed spectra to get a better understanding of the physical ... More
Improved Hubble Space Telescope Proper Motions for Tycho-G and Other Stars in the Remnant of Tycho's Supernova 1572Dec 19 2013With archival and new Hubble Space Telescope observations we have refined the space-velocity measurements of the stars in the central region of the remnant of Tycho's supernova (SN) 1572, one of the historical Galactic Type Ia supernova remnants (SNRs). ... More
Mapping the Kinematical Regimes of Semi-Inclusive Deep Inelastic ScatteringApr 29 2019We construct a language for identifying kinematical regions of transversely differential semi-inclusive deep inelastic scattering cross sections with particular underlying partonic pictures, especially in regions of moderate to low $Q$ where sensitivity ... More
Room temperature ferromagnetic-like behavior in Mn-implanted and post-annealed InAs layers deposited by Molecular Beam EpitaxyApr 14 2009We report on the magnetic and structural properties of Ar and Mn implanted InAs epitaxial films grown on GaAs (100) by Molecular Beam Epitaxy (MBE) and the effect of Rapid Thermal Annealing (RTA) for 30 seconds at 750C. Channeling Particle Induced X- ... More
Extracting the Kaon Collins function from $e^+e^-$ hadron pair production dataDec 07 2015The latest data released by the BaBar Collaboration on azimuthal correlations measured for pion-kaon and kaon-kaon pairs produced in $e^+e^-$ annihilations allow, for the first time, a direct extraction of the kaon Collins functions. These functions are ... More
Collins functions for pions from SIDIS and new e+e- data: a first glance at their transverse momentum dependenceOct 19 2015New data from Belle and BaBar Collaborations on azimuthal asymmetries, measured in e+e- annihilations into pion pairs at Q^2=112 GeV^2, allow to take the first, direct glance at the transverse momentum dependence of the Collins functions, in addition ... More
Solar analogs with and without planets: T$_c$ trends and galactic evolutionJan 03 2015Jan 06 2015We explore a sample of 148 solar-like stars to search for a possible correlation between the slopes of the abundance trends versus condensation temperature (known as the Tc slope) both with stellar parameters and Galactic orbital parameters in order to ... More
Volatiles and refratories in solar analogs: no terrestial planet connectionNov 29 2010We have analysed very high-quality HARPS and UVES spectra of 95 solar analogs, 24 hosting planets and 71 without detected planets, to search for any possible signature of terrestial planets in the chemical abundances of volatile and refractory elements ... More
Two planetary systems with transiting Earth-size and super-Earth planets orbiting late-type dwarf starsJun 04 2018Jun 05 2018We present two new planetary systems found around cool dwarf stars with data from the K2 mission. The first system was found in K2-239 (EPIC 248545986), char- acterized in this work as M3.0V and observed in the 14th campaign of K2. It consists of three ... More
LOLAS-2 : redesign of an optical turbulence profilerJun 16 2016We present the development, tests and first results of the second generation Low Layer Scidar (LOLAS-2). This instrument constitutes a strongly improved version of the prototype Low Layer Scidar, which is aimed at the measurement of optical turbulence ... More
A survey for pulsating subdwarf B stars with the Nordic Optical TelescopeJan 20 2010A search programme for pulsating subdwarf B stars was conducted with the Nordic Optical Telescope on La Palma over 59 nights between 1999 and 2009. The purpose of the programme was to significantly extend the number of rapidly pulsating sdB stars to better ... More
High-pressure phase transitions and compressibility of wolframite-type tungstatesNov 30 2009This paper reports an investigation on the phase diagram and compressibility of wolframite-type tungstates by means of x-ray powder diffraction and absorption in a diamond-anvil cell and ab initio calculations. The diffraction experiments show that monoclinic ... More
Temporal changes of the flare activity of Proxima CenMay 17 2019We study temporal variations of the emission lines of Halpha, Hepsilon, H and K Ca II, D1 and D2 Na I, 4026 and 5876 A He I in the HARPS spectra of Proxima Centauri across an extended time of 13.2 years, from May 27, 2004, to September 30, 2017. Aims. ... More
Doppler and modulation tomography of XTE J1118+480 in quiescenceMay 11 2009We present Doppler and modulation tomography of the X-ray nova XTE J1118+480 with data obtained during quiescence using the 10-m Keck II telescope. The hot spot where the gas stream hits the accretion disc is seen in H-Alpha, H-Beta, He I Lambda-5876, ... More
An equatorial ultra iron-poor star identified in BOSSMay 20 2015We report the discovery of SDSS J131326.89-001941.4, an ultra iron-poor red giant star ([Fe/H] ~ -4.3) with a very high carbon abundance ([C/Fe]~ +2.5). This object is the fifth star in this rare class, and the combination of a fairly low effective temperature ... More
Arc Discharge Carbon Nanoonions Purification by Liquid-Liquid ExtractionNov 27 2017Carbon nanoonions are novel carbon nanoestructures that have potential applications in fields like electronics and chemical catalysis. Here we report a very simple but effective method of purifying carbon nanoonions produced by submerged arc discharge ... More
A new approach to the Child-Langmuir lawJun 24 2015We analyze the motion of charged particles in a vacuum tube diode using a new set of variables. We obtain the space charge limited current for a charged particle moving non-relativistically in one dimension for the case of zero and non zero initial velocity. ... More
Invariant Differential Equations and the Adler-Gel'fand-Dikii BracketMar 29 1996In this paper we find an explicit formula for the most general vector evolution of curves on $RP^{n-1}$ invariant under the projective action of $SL(n,R)$. When this formula is applied to the projectivization of solution curves of scalar Lax operators ... More
Automatically Detecting Self-Reported Birth Defect Outcomes on Twitter for Large-scale Epidemiological ResearchOct 22 2018In recent work, we identified and studied a small cohort of Twitter users whose pregnancies with birth defect outcomes could be observed via their publicly available tweets. Exploiting social media's large-scale potential to complement the limited methods ... More
A system of three transiting super-Earths in a cool dwarf starJan 18 2018Mar 13 2018We present the detection of three super-Earths transiting the cool star LP415-17, monitored by K2 mission in its 13th campaign. High resolution spectra obtained with HARPS-N/TNG showed that the star is a mid-late K dwarf. Using spectral synthesis models ... More
Exploring the alpha-enhancement of metal-poor planet-hosting stars. The Kepler and HARPS samplesSep 27 2012Nov 07 2012Recent studies showed that at low metallicities Doppler-detected planet-hosting stars have preferably high alpha-content and belong to the thick disk. We used the reconnaissance spectra of 87 Kepler planet candidates and data available from the HARPS ... More
Spatial Cross Spectrum: Reducing Incoherent Convective Background of Resolved Heloseismic InstrumentsOct 09 2008Measurements of low-order p modes and gravity modes are perturbed by the solar convective background. Such perturbation increases below 2mHz for intensity measurements and 1mHz for velocity measurements. While the low-degree modes have large spatial scales, ... More
MHD Remote Numerical Simulations: Evolution of Coronal Mass EjectionsDec 22 2008Coronal mass ejections (CMEs) are solar eruptions into interplanetary space of as much as a few billion tons of plasma, with embedded magnetic fields from the Sun's corona. These perturbations play a very important role in solar--terrestrial relations, ... More
Error estimates for splitting methods based on AMF-Runge-Kutta formulas for the time integration of advection diffusion reaction PDEsJan 12 2015The convergence of a family of AMF-Runge-Kutta methods (in short AMF-RK) for the time integration of evolutionary Partial Differential Equations (PDEs) of Advection Diffusion Reaction type semi-discretized in space is considered. The methods are based ... More
Two step robust fringe analysis method with random shiftAug 03 2015We propose a two steps fringe analysis method assuming random phase step and changes in the illumination conditions. Our method constructs on a Gabor Filter--Bank (GFB) that independently estimates the phase from the fringe patterns and filters noise. ... More
Reduction Signals Method Preserving Spatial and Temporal CapabilitiesJun 22 2018In gamma ray imaging, a scintillation crystal is typically used to convert the gamma radiation into visible light. Photosensors are used to transform this light into measurable signals. Several types of photosensors are currently in use depending on the ... More
Proper motions of the HH1 jetAug 04 2017We describe a new method for determining proper motions of extended objects, and a pipeline developed for the application of this method. We then apply this method to an analysis of four epochs of [S~II] HST images of the HH~1 jet (covering a period of ... More
Effective su_q(2) models and polynomial algebras for fermion-boson HamiltoniansJul 25 2007Schematic su(2)+h3 interaction Hamiltonians, where su(2) plays the role of the pseudo-spin algebra of fermion operators and h3 is the Heisenberg algebra for bosons, are shown to be closely related to certain nonlinear models defined on a single quantum ... More
Optical spectroscopy of local type-1 AGN LINERsJul 04 2018The Balmer emission originated in the broad line region (BLR) of active galactic nuclei (AGNs) could be either weak and difficult to detect, or even absent, for low luminosity AGNs, as LINERs. Our goals in this paper are threefold. First, we want to explore ... More
Kinematics and chemical properties of the Galactic stellar populations. The HARPS FGK dwarfs sampleApr 09 2013Apr 10 2013(Abridged) We analyze chemical and kinematical properties of about 850 FGK solar neighborhood long-lived dwarfs observed with the HARPS high-resolution spectrograph. The stars in the sample have logg > 4 dex, 5000 < Teff < 6500 K, and -1.39 < [Fe/H] < ... More
Stars with and without planets: Where do they come from?Oct 28 2014A long and thorough investigation of chemical abundances of planet-hosting stars that lasted for more than a decade has finally beared fruit. We explore a sample of 148 solar-like stars to search for a possible correlation between the slopes of the abundance ... More
On the origin of stars with and without planets. Tc trends and clues to Galactic evolutionApr 17 2014We explore a sample of 148 solar-like stars to search for a possible correlation between the slopes of the abundance trends versus condensation temperature (known as the Tc slope) with stellar parameters and Galactic orbital parameters in order to understand ... More
The Pristine survey II: a sample of bright stars observed with FEROSMay 29 2017Extremely metal-poor (EMP) stars are old objects formed in the first Gyr of the Universe. They are rare and, to select them, the most successful strategy has been to build on large and low-resolution spectroscopic surveys. The combination of narrow- and ... More
Lithium in the Globular Cluster NGC 6397: Evidence for dependence on evolutionary statusSep 07 2009Oct 13 2009Most Globular Clusters are believed to host a single stellar populations. They can thus be considered a good place to study the Spite plateau and probe for possible evolutionary modifications of the Li content. We want to determine the Li content of subgiant ... More
Overabundance of alpha-elements in exoplanet host starsMay 30 2012Jun 04 2012We present the results for a chemical abundance analysis between planet-hosting and stars without planets for 12 refractory elements for a total of 1111 nearby FGK dwarf stars observed within the context of the HARPS GTO programs. Of these stars, 109 ... More
Photon rockets and the Robinson-Trautman geometriesMar 19 2002We point out the relation between the photon rocket spacetimes and the Robinson Trautman geometries. This allows a discussion of the issues related to the distinction between the gravitational and matter energy radiation that appear in these metrics in ... More
Interference Spins: Scheduling of Multiple Interfering Two-Way Wireless LinksJan 06 2015Feb 04 2015Two-way is a dominant mode of communication in wireless systems. Departing from the tradition to optimize each transmission direction separately, recent work has demonstrated that, for time-division duplex (TDD) systems, optimizing the schedule of the ... More
Graphene wormholes: A condensed matter illustration of Dirac fermions in curved spaceSep 16 2009We study the properties of graphene wormholes in which a short nanotube acts as a bridge between two graphene sheets, where the honeycomb carbon lattice is curved from the presence of 12 heptagonal defects. By taking the nanotube bridge with very small ... More
Orbit equivalence of linear systems on manifolds and semigroup actions on homogeneous spacesSep 27 2016In this paper we introduce the notion of orbit equivalence for semigroup actions and the concept of generalized linear control system on smooth manifold. The main goal is to prove that, under certain conditions, the semigroup system of a generalized linear ... More
Entropy and anisotropyJan 23 2007We address the problem of defining the concept of entropy for anisotropic cosmological models. In particular, we analyze for the Bianchi I and V models the entropy which follows from postulating the validity of the laws of standard thermodynamics in cosmology. ... More
GIARPS@TNG GIANO-B & HARPS-N together for a wider wavelength range spectroscopyJul 14 2017Jul 18 2017Since 2012, thanks to the installation of the high resolution echelle spectrograph in the optical range HARPS-N, the Italian telescope TNG (La Palma) became one of the key facilities for the study of the extrasolar planets. In 2014 TNG also offered GIANO ... More
Effect of pre-oxidation treatments on the structural, microstructural, and chemical properties of (Ni,Pt)Al systemsNov 06 2018The effect of isothermal pre-oxidation treatments on the \b{eta}-(Ni,Pt)Al + Ren\'e N5 system degradation is here reported. The oxidation treatments were carried out from 900 (mostly {\theta}-Al2O3 growing conditions) to 1200{\deg}C (mainly {\alpha}-Al2O3 ... More
General fluctuations of the type II pure spinor string on curved backgroundsFeb 06 2019Mar 30 2019The general fluctuations, in the form of vertex operators, for the type II superstring in the pure spinor formalism are considered. We review the construction of these vertex operators in flat space-time. We then review the type II superstrings in curved ... More
There is a $+$-Ramsey \textsf{MAD} familyOct 20 2018We answer an old question of Michael Hru\v{s}\'{a}k by constructing a $+$-Ramsey \textsf{MAD} family without the need of any additional axioms beyond $\mathsf{ZFC.}$ We also prove that every Miller-indestructible \textsf{MAD }family is $+$-Ramsey, this ... More
A Brief Introduction to Machine Learning for EngineersSep 08 2017May 17 2018This monograph aims at providing an introduction to key concepts, algorithms, and theoretical results in machine learning. The treatment concentrates on probabilistic models for supervised and unsupervised learning problems. It introduces fundamental ... More
General fluctuations of the heterotic pure spinor string on curved backgroundsDec 12 2018Feb 19 2019The general fluctuations, in the form of vertex operators, for the heterotic superstring in the pure spinor formalism are considered. The case of a flat background is reviewed and the case of a curved case is studied. The left-moving ghosts are pure spinors ... More
The b Ghost of the Pure Spinor Formalism is NilpotentAug 10 2010Sep 28 2010The ghost for world-sheet reparametrization invariance is not a fundamental field in the pure spinor formalism. It is written as a combination of pure spinor variables which have conformal dimension two and such that it commutes with the BRST operator ... More
A theory of superconductivity in multi-walled carbon nanotubesMar 10 2006Jun 26 2006We devise an approach to describe the electronic instabilities of doped multi-walled nanotubes, where each shell has in general a manifold of Fermi points. Our analysis relies on the scale dependence of the different scattering processes, showing that ... More
Statistical physics of directional, stochastic chains with memoryNov 19 2015Stochastic chains represent a wide and key variety of phenomena in many branches of science within the context of Information Theory and Thermodynamics. They are typically approached by a sequence of independent events or by a memoryless Markov process. ... More
Source Coding with in-Block Memory and Causally Controllable Side InformationJan 05 2013The recently proposed set-up of source coding with a side information "vending machine" allows the decoder to select actions in order to control the quality of the side information. The actions can depend on the message received from the encoder and on ... More
A Note on T-dualities in the Pure Spinor Heterotic StringFeb 16 2009Feb 20 2009In this note we study the preservation of the classical pure spinor BRST constraints under super T-duality transformations. We also determine the invariance of the one-loop conformal invariance and of the local gauge and Lorentz anomalies under the super ... More
Na I and H$α$ absorption features in the atmosphere of MASCARA-2b/KELT-20bMay 08 2018We have used the HARPS-North high resolution spectrograph ($\mathcal{R}$=115 000) at TNG to observe one transit of the highly irradiated planet MASCARA-2b/KELT-20b. Using only one transit observation, we are able to clearly resolve the spectral features ... More
A general framework for microscopically reversible processes with memoryNov 25 2015Oct 25 2016Statistical Mechanics deals with ensembles of microstates that are compatible with fixed constraints and that on average define a thermodynamic macrostate. The evolution of a small system is normally subjected to changing constraints and involve a stochastic ... More
A general theory for irreversible thermodynamicsNov 26 2015We demonstrate that irreversibility arises from the principle of microscopic reversibility and the presence of memory in the time evolution of a single copy of a system driven by a protocol. We introduce microscopic reversibility by using the concept ... More
Abundance trend with condensation temperature for stars with different Galactic birth placesJun 15 2016During the past decade, several studies reported a correlation between chemical abundances of stars and condensation temperature (also known as Tc trend). However, the real astrophysical nature of this correlation is still debated. The main goal of this ... More
Jacobi osculating rank and isotropic geodesics on naturally reductive 3-manifoldsDec 13 2007We study the Jacobi osculating rank of geodesics on naturally reductive homogeneous manifolds and we apply this theory to the 3-dimensional case. Here, each non-symmetric, simply connected naturally reductive 3-manifold can be given as a principal bundle ... More
$ζ^2$ Ret, its debris disk, and its lonely stellar companion $ζ^1$ Ret. Different $T_{\mathrm{c}}$ trends for different spectraMay 06 2016Several studies have reported a correlation between the chemical abundances of stars and condensation temperature (known as Tc trend). Very recently, a strong Tc trend was reported for the $\zeta$ Reticuli binary system, which consists of two solar analogs. ... More
Identifying the best iron-peak and $α$-capture elements for chemical tagging: The impact of the number of lines on measured scatterSep 08 2015The main goal of this work is to explore which elements carry the most information about the birth origin of stars and as such that are best suited for chemical tagging. We explored different techniques to minimize the effect of outlier value lines in ... More
Local helioseismology of sunspot regions: comparison of ring-diagram and time-distance resultsNov 03 2010Local helioseismology provides unique information about the subsurface structure and dynamics of sunspots and active regions. However, because of complexity of sunspot regions local helioseismology diagnostics require careful analysis of systematic uncertainties ... More
A Very Brief Introduction to Machine Learning With Applications to Communication SystemsAug 07 2018Nov 05 2018Given the unprecedented availability of data and computing resources, there is widespread renewed interest in applying data-driven machine learning methods to problems for which the development of conventional engineering solutions is challenged by modelling ... More