Results for "Saida M. Caballero-Nieves"

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An Axiomatic Review of Israel-Stewart Hydrodynamics and Extended Irreversible ThermodynamicsMay 16 2017The causality of dissipative phenomena can not be treated in traditional theories of dissipations, Fourier laws and Navier-Stokes equations. This is the reason why the dissipative phenomena have not been studies well in relativistic situations. Furthermore, ... More
Massive, wide binaries as tracers of massive star formationFeb 13 2018Massive stars can be found in wide (hundreds to thousands AU) binaries with other massive stars. We use $N$-body simulations to show that any bound cluster should always have approximately one massive wide binary: one will probably form if none are present ... More
The Heavy Quark Spin Symmetry Partners of the X(3872)Apr 12 2012Sep 27 2012We explore the consequences of heavy quark spin symmetry for the charmed meson-antimeson system in a contact-range (or pionless) effective field theory. As a trivial consequence, we theorize the existence of a heavy quark spin symmetry partner of the ... More
Alternating strain regimes for failure propagation in flexural systemsApr 18 2019We consider both analytical and numerical studies of a steady-state fracture process inside a discrete mass-beam structure, composed of periodically placed masses connected by Euler-Bernoulli beams. A fault inside the structure is assumed to propagate ... More
Heavy Quark Spin Symmetry and SU(3)-Flavour Partners of the X(3872)Nov 29 2012In this work, an Effective Field Theory (EFT) incorporating light SU(3)-flavour and heavy quark spin symmetry is used to describe charmed meson-antimeson bound states. At Lowest Order (LO), this means that only contact range interactions among the heavy ... More
The high-energy emission from GX 339-4 as seen with INTEGRAL and XMM-NewtonDec 07 2008GX 339--4 is a well-known microquasar. In this contribution we show the obtained results with the INTEGRAL and XMM-Newton observatories of the outburst undertaken on 2007. The observations cover spectral evolution from the hard, soft intermediate states ... More
The high energy emission from black holesNov 06 2007The origin of the high energy emission (X-rays and gamma-rays) from black holes is still a matter of debate. We present new evidence that hard X-ray emission in the low/hard state may not be dominated by thermal Comptonization. We present an alternative ... More
The electric field as a novel switch for uptake/release of hydrogen storage in nitrogen doped grapheneNov 24 2011Nitrogen-doped graphene was recently synthesized and was reported to be a catalyst for hydrogen dissociative adsorption under a perpendicular applied electric field (F). In this work, the diffusion of H atoms on N-doped graphene, in the presence and absence ... More
A High Angular Resolution Survey of Massive Stars in Cygnus OB2: Results from the Hubble Space Telescope Fine Guidance SensorsNov 20 2013We present results of a high angular resolution survey of massive OB stars in the Cygnus OB2 association that we conducted with the Fine Guidance Sensor 1R (FGS1r) on the Hubble Space Telescope. FGS1r is able to resolve binary systems with a magnitude ... More
Study of the feasibility of a compact gamma camera for real-time cancer assessmentFeb 13 2018Results from the simulations of a Compton gamma camera based on compact configuration of detectors consisting in two detection modules, each of them having two stages of high-resolution position- and energy-sensitive radiation detectors operated in time-coincidence ... More
Diffusive and arrested-like dynamics in currency exchange marketsMar 09 2017This work studies the symmetry between colloidal dynamics and the dynamics of the Euro--US Dollar currency exchange market (EURUSD). We consider the EURUSD price in the time range between 2001 and 2015, where we find significant qualitative symmetry between ... More
X-ray Reverberation Observational Modelling in Active Galactic NucleiJan 14 2019Feb 19 2019X-ray reverberation in Active Galactic Nuclei, believed to be the result of the reprocessing of coronal photons by the underlying accretion disc, has allowed us to probe the properties of the inner-most regions of the accretion flow and the central black ... More
Black hole radiation with high frequency dispersionMay 11 1999Aug 24 1999We consider one model of a black hole radiation, in which the equation of motion of a matter field is modified to cut off high frequency modes. The spectrum in the model has already been analytically derived in low frequency range, which has resulted ... More
Neutrino effective potential in a fermion and scalar backgroundAug 05 2018We consider the neutrino self-energy in a background composed of a scalar particle and a fermion using a simple model for the coupling of the form $\lambda\bar f_R\nu_L\phi$. The results are useful in the context of Dark Matter-neutrino interaction models ... More
Neutrino propagation in an electron background with an inhomogeneous magnetic fieldJun 28 2017Jul 28 2018We study the electromagnetic coupling of a neutrino that propagates in a two-stream electron background medium. Specifically, we calculate the electromagnetic vertex function for a medium that consists of a \emph{normal} electron background plus another ... More
Engaging Physics Faculty in Course TransformationJul 11 2014Sep 30 2014Research has shown that it is challenging to change departmental culture to support the adoption of transformed teaching practices. Michigan State University is working to transform its introductory physics courses by engaging faculty in discussions about ... More
Chiral spin-3/2 particles in a mediumMay 03 2016We consider the propagation of a chiral spin-3/2 particle in a background medium using the Thermal Field Theory (TFT) method, in analogy to the cases of a spin-1/2 fermion (e.g., a neutrino) and the photon. We present a systematic decomposition of the ... More
A Knowledge Representation Perspective on Activity TheoryNov 14 2018Intelligent technologies, in particular systems to promote health and well-being, are inherently centered around the human being, and they need to interrelate with human activities at their core. While social sciences provide angles to study such activities, ... More
The influence of antiphase boundary of the MnAl $τ$-phase on the energy productMar 15 2019In this work we use a multiscale approach toward a realistic design of a permanent magnet based on MnAl $\tau$-phase and elucidate how the antiphase boundary defects present in this material affect the energy product. We show how the extrinsic properties ... More
On the minimum of a conditioned Brownian bridgeNov 18 2015Nov 13 2017We study the law of the minimum of a Brownian bridge, conditioned to take specific values at specific points, and the law of the location of the minimum. They are used to compare some non-adaptive optimisation algorithms for black-box functions for which ... More
Thickness dependent enhancement of the polar magneto-optic Kerr effect in Co magnetoplasmonic nanostructuresOct 31 2016Feb 20 2019Large surface plasmon polariton assisted enhancement of the magneto-optical activity has been observed in the past, through spectral measurements of the polar Kerr rotation in Co hexagonal antidot arrays. Here, we report a strong thickness dependence, ... More
Heavy quark spin symmetric molecular states from ${\bar D}^{(*)}Σ_c^{(*)}$ and other coupled channels in the light of the recent LHCb pentaquarksApr 02 2019We consider the ${\bar D}^{(*)}\Sigma_c^{(*)}$ states, together with $J/\psi N$ and other coupled channels, and take an interaction consistent with heavy quark spin symmetry, with the dynamical input obtained from an extension of the local hidden gauge ... More
Minimax Hausdorff estimation of density level setsMay 07 2019Given a random sample of points from some unknown density, we propose a data-driven method for estimating density level sets under the r-convexity assumption. This shape condition generalizes the convexity property. However, the main problem in practice ... More
Empathic Autonomous AgentsFeb 20 2019Identifying and resolving conflicts of interests is a key challenge when designing autonomous agents. For example, such conflicts often occur when complex information systems interact persuasively with humans and are in the future likely to arise in non-human ... More
Meso-scale models and approximate solutions for solids containing clouds of voidsJan 29 2015For highly perforated domains the paper addresses a novel approach to study mixed boundary value problems for the equations of linear elasticity in the framework of meso-scale approximations. There are no assumptions of periodicity involved in the description ... More
Implementing Argumentation-enabled Empathic AgentsDec 12 2018In a previous publication, we introduced the core concepts of empathic agents as agents that use a combination of utility-based and rule-based approaches to resolve conflicts when interacting with other agents in their environment. In this work, we implement ... More
$Ω_c$ excited states with heavy-quark spin symmetryNov 13 2018We study the $C=1$, $S=-2$, $I=0$ sector, where five excited $\Omega_c$ states have been recently observed by the LHCb Collaboration. We start from a recently developed unitarized baryon-meson model that takes, as bare baryon-meson interaction, an extended ... More
Neutron Transfer Studied with a Radioactive beam of 24Ne, using TIARA at SPIRALDec 20 2009A general experimental technique for high resolution studies of nucleon transfer reactions using radioactive beams is briefly described, together with the first new physics results that have been obtained with the new TIARA array. These first results ... More
Understanding Student Computational Thinking with Computational ModelingJul 07 2012Sep 07 2012Recently, the National Research Council's framework for next generation science standards highlighted "computational thinking" as one of its "fundamental practices". 9th Grade students taking a physics course that employed the Modeling Instruction curriculum ... More
Comparing Spectral Models for ULXs with NGC 4517 ULX1Jan 24 2011We present the previously unanalysed high quality XMM-Newton spectrum of an ultraluminous X-ray source candidate in NGC 4517. As with other high quality ULX spectra, a downturn in the spectrum is observed at ~6 keV. Both of the recent disc reflection ... More
Geometric properties of surfaces with the same mean curvature in R^3 and L^3Apr 14 2016Spacelike surfaces in the Lorentz-Minkowski space L^3 can be endowed with two different Riemannian metrics, the metric inherited from L^3 and the one induced by the Euclidean metric of R^3. It is well known that the only surfaces with zero mean curvature ... More
Peer Evaluation of Video Lab Reports in an Introductory Physics MOOCJul 17 2014Oct 15 2014Assessing student performance becomes challenging when course enrollment becomes very large (~10^4 students). As part of a Massive Open Online Course (MOOC) in introductory physics offered by Georgia Tech in 2013, students submitted video reports on mechanics ... More
Peer Evaluation of Video Lab Reports in a Blended Introductory Physics CourseJul 11 2014Oct 14 2014The Georgia Tech blended introductory calculus-based mechanics course emphasizes scientific communication as one of its learning goals, and to that end, we gave our students a series of four peer-evaluation assignments intended to develop their abilities ... More
On the Prevalence and Nature of Computational Instruction in Undergraduate Physics Programs across the United StatesDec 20 2017Aug 20 2018A national survey of physics faculty was conducted to investigate the prevalence and nature of computational instruction in physics courses across the United States. 1246 faculty from 357 unique institutions responded to the survey. The results suggest ... More
Neutrino dispersion relation in a magnetized multi-stream matter backgroundJun 28 2017Jul 28 2018We study the propagation of a neutrino in a medium that consists of two or more thermal backgrounds of electrons and nucleons moving with some relative velocity, in the presence of a static and homogeneous electromagnetic field. We calculate the neutrino ... More
Field theory of the photon self-energy in a medium with a magnetic field and the Faraday effectAug 15 2002A convenient and general decomposition of the photon self-energy in a magnetized, but otherwise isotropic, medium is given in terms of the minimal set of tensors consistent with the transversality condition. As we show, the self-energy in such a medium ... More
The relative and absolute timing accuracy of the EPIC-pn camera on XMM-Newton, from X-ray pulsations of the Crab and other pulsarsApr 04 2012Reliable timing calibration is essential for the accurate comparison of XMM-Newton light curves with those from other observatories, to ultimately use them to derive precise physical quantities. The XMM-Newton timing calibration is based on pulsar analysis. ... More
Absorption line indices in the UV. Empirical and theoretical stellar population modelsNov 04 2008(Abridged). Stellar absorption lines in the optical have been extensively studied and constitute an important stellar population diagnostic for galaxies in the local universe and up to moderate redshifts. Proceeding towards higher look-back times, galaxies ... More
$η$ bound states in nucleiJun 11 2002The energies and widths of bound states of the $\eta$ meson in different nuclei are obtained using the results for its selfenergy in a nuclear medium, which is evaluated in a selfconsistent manner using techniques of unitarized chiral perturbation theory. ... More
Vibrations and elastic waves in chiral multi-structuresMay 03 2018We develop a new asymptotic model of the dynamic interaction between an elastic structure and a system of gyroscopic spinners that make the overall multi-structure chiral. An important result is the derivation and analysis of effective chiral boundary ... More
A study of the 15 micron quasars in the ELAIS N1 and N2 fieldsAug 03 2004This paper discusses properties of the European Large Area ISO Survey 15 micron quasars and tries to establish a robust method of quasar selection for future use within the Spitzer Wide-Area Infrared Extragalactic Survey (SWIRE) framework. The importance ... More
The MalSource Dataset: Quantifying Complexity and Code Reuse in Malware DevelopmentNov 16 2018During the last decades, the problem of malicious and unwanted software (malware) has surged in numbers and sophistication. Malware plays a key role in most of today's cyber attacks and has consolidated as a commodity in the underground economy. In this ... More
A Lattice Study of Semi-leptonic Decays of $D$-MesonsDec 02 1994We present results of a lattice computation of the matrix elements of the vector and axial-vector currents which are relevant for the semi-leptonic decays $D \rightarrow K$ and $D \rightarrow K^*$. The computations are performed in the quenched approximation ... More
Learning Human-Aware Path Planning with Fully Convolutional NetworksMar 01 2018Jul 17 2018This work presents an approach to learn path planning for robot social navigation by demonstration. We make use of Fully Convolutional Neural Networks (FCNs) to learn from expert's path demonstrations a map that marks a feasible path to the goal as a ... More
Properties of dusty tori in AGN: I. The Case of SWIRE/SDSS QuasarsFeb 18 2008Jun 05 2008We derive the properties of dusty tori in Active Galactic Nuclei (AGN) from the comparison of observed Spectral Energy Distributions (SEDs) of SDSS quasars and a precomputed grid of torus models. The observed SEDs comprise SDSS photometry, 2MASS J, H, ... More
Neutrino Interactions Importance for Nuclear PhysicsSep 07 2009We review the general interplay between Nuclear Physics and neutrino-nucleus cross sections at intermediate and high energies. The effects of different reaction mechanisms over the neutrino observables are illustrated with examples in calculations using ... More
Database of novel magnetic materials for high-performance permanent magnet developmentFeb 14 2019This paper describes the open Novamag database that has been developed for the design of novel Rare-Earth free/lean permanent magnets. The database software technologies, its friendly graphical user interface, advanced search tools and available data ... More
Liquid-gas separation in colloidal electrolytesAug 10 2005Oct 26 2005The liquid-gas transition of an electroneutral mixture of oppositely charged colloids, studied by Monte Carlo simulations, is found in the low temperature -- low density region. The critical temperature shows a non-monotonous behavior as a function of ... More
Joint H-alpha and X-Ray Observations of Massive X-Ray Binaries. II. The Be X-ray Binary and Microquasar LS I +61 303Oct 19 2006We present the results of an H-alpha monitoring campaign on the BeXRB and microquasar system LS I +61 303. We use radial velocity measurements of HeI lines in our spectra to re-evaluate the orbital elements and to better establish the time of periastron. ... More
Optically faint massive Balmer Break Galaxies at z>3 in the CANDELS/GOODS fieldsJun 11 2018We present a sample of 33 Balmer Break Galaxies (BBGs) selected as dropouts in the deepest HST/F160W images of the two CANDELS/GOODS fields (i.e., $H\gtrsim27.3$ mag) but relatively bright in Spitzer/IRAC ($[3.6],[4.5]<24.5$ mag). Half of these BBGs are ... More
A probabilistic atlas of the human thalamic nuclei combining ex vivo MRI and histologyJun 22 2018The human thalamus is a brain structure that comprises numerous, highly specific nuclei. Since these nuclei are known to have different functions and to be connected to different areas of the cerebral cortex, it is of great interest for the neuroimaging ... More
Optically-faint massive Balmer Break Galaxies at z>3 in the CANDELS/GOODS fieldsJun 11 2018Mar 29 2019We present a sample of 33 Balmer Break Galaxies (BBGs) selected as HST/F160W dropouts in the deepest CANDELS/GOODS fields ($H\gtrsim27.3$~mag) but relatively bright in {\it Spitzer}/IRAC ($[3.6],[4.5]<24.5$~mag), implying red colors (median and quartiles: ... More
How to Measure the Black Hole's Mass, Spin Parameter and Inclination Angle in Kerr Lens Effect 1: Principle and FormalismJun 15 2016We propose the principle of measuring the Kerr BH's mass, spin parameter and the direction of the spin axis through observing two quantities of the spinning strong gravitational lens effect of the BH. Those observable quantities are generated by two rays ... More
Geometrical control of active turbulence in curved topographiesMay 03 2018We investigate the turbulent dynamics of a two-dimensional active nematic liquid crystal con- strained on a curved surface. Using a combination of hydrodynamic and particle-based simulations, we demonstrate that the fundamental structural features of ... More
Heavy-quark spin symmetry for charmed and strange baryon resonancesDec 17 2012Jan 18 2013We study charmed and strange baryon resonances that are generated dynamically by a unitary baryon-meson coupled-channels model which incorporates heavy-quark spin symmetry. This is accomplished by extending the SU(3) Weinberg-Tomozawa chiral Lagrangian ... More
Elastic s-wave scattering phase shifts and |Vub| from lattice calculations of form factors for exclusive semileptonic decaysNov 21 2007Omnes dispersion relations make a connection between form factors for exclusive semileptonic decays and phase shifts in the corresponding elastic scattering channels. We describe two applications. In the first, we use lattice form factor calculations ... More
Ultracool dwarf benchmarks with \emph{Gaia} primariesJun 19 2017We explore the potential of \emph{Gaia} for the field of benchmark ultracool/brown dwarf companions, and present the results of an initial search for metal-rich/metal-poor systems. A simulated population of resolved ultracool dwarf companions to \emph{Gaia} ... More
Non-Hermitian Dynamics in the Quantum Zeno LimitOct 16 2015Jul 13 2016Measurement is one of the most counter-intuitive aspects of quantum physics. Frequent measurements of a quantum system lead to quantum Zeno dynamics where time evolution becomes confined to a subspace defined by the projections. However, weak measurement ... More
Dynamic heterogeneity in an orientational glassSep 14 2017Nov 18 2017Family of compounds CBr$_n$Cl$_{4-n}$ has been proven helpful in unraveling microscopic mechanisms responsible of glassy behavior. Some of the family members show translational ordered phases with minimal disorder which appears to reveal glassy features, ... More
A0535+26 in the April 2010 outburst: probing the accretion regime at workMar 25 2013A number of accreting X-ray pulsars experience spectral changes, both on the long time scales and on the time scales of the neutron star spin period. The sources seem to form two distinct groups which differ by the type of the spectral variations with ... More
Fostering Computational ThinkingDec 21 2011Students taking introductory physics are rarely exposed to computational modeling. In a one-semester large lecture introductory calculus-based mechanics course at Georgia Tech, students learned to solve physics problems using the VPython programming environment. ... More
The Plastic and Liquid Phases of CCl$_3$Br Studied by Molecular Dynamics SimulationsJul 12 2013We present a molecular dynamics study of the liquid and plastic crystalline phases of CCl$_3$Br. We investigated the short-range orientational order using a recently developed classification method and we found that both phases behave in a very similar ... More
Deep Hashing using Entropy Regularised Product Quantisation NetworkFeb 11 2019In large scale systems, approximate nearest neighbour search is a crucial algorithm to enable efficient data retrievals. Recently, deep learning-based hashing algorithms have been proposed as a promising paradigm to enable data dependent schemes. Often ... More
A 15um selected sample of high-z starbursts and AGNsOct 25 2006We report results from a Spitzer GO-1 program of IRS spectroscopy of a large sample of Luminous Infrared Galaxies and quasars selected from the European Large Area ISO Survey (ELAIS) which have a wide multiwavelength coverage, including ISOCAM, ISOPHOT, ... More
Magnetic fields in M dwarfs from the CARMENES surveyApr 29 2019M dwarfs are known to generate the strongest magnetic fields among main-sequence stars with convective envelopes, but the link between the magnetic fields and underlying dynamo mechanisms, rotation, and activity still lacks a consistent picture. In this ... More
Sloan Digital Sky Survey Quasars in the SWIRE ELAIS N1 Field: Properties and Spectral Energy DistributionsOct 26 2004We present a mid-infrared analysis of 35 quasars with spectroscopic redshifts selected from the Spitzer Wide-area InfraRed Extragalactic Survey (SWIRE). We discuss their optical and mid-infrared (MIR) colors, and show that these quasars occupy well defined ... More
Elastic s-wave B pi, D pi, D K and K pi scattering from lattice calculations of scalar form factors in semileptonic decaysMar 05 2007Apr 09 2007We show how theoretical, principally lattice, calculations of the scalar form factors in semileptonic pseudoscalar-to-pseudoscalar decays can be used to extract information about the corresponding elastic s-wave scattering channels. We find values for ... More
Semileptonic bc to cc Baryon Decay and Heavy Quark Spin SymmetryJun 19 2007Aug 14 2007We study the semileptonic decays of the lowest-lying bc baryons to the lowest-lying cc baryons (Xi_{bc}^{(\prime*)}--> Xi_{cc}^{(*)} and Omega_{bc}^{(\prime*)}--> Omega_{cc}^{(*)}), in the limit m_b, m_c >> Lambda_{QCD} and close to the zero recoil point. ... More
|Vub| from exclusive semileptonic B to pi decays revisitedMay 24 2007Sep 04 2007We update the extraction of |Vub| from exclusive semileptonic B to pi decays, combining experimental partial branching fraction information with theoretical form factor calculations, using the recently revised HPQCD results for the form factors f_+ and ... More
Extracting |V(ub)| from B->pi l nu Decays Using a Multiply-subtracted Omnes Dispersion RelationJul 24 2006Dec 17 2006We use a multiply-subtracted Omnes dispersion relation for the form factor f^+ in B->pi semileptonic decay, allowing the direct input of experimental and theoretical information to constrain its dependence on q^2. Apart from these inputs we use only unitarity ... More
The CARMENES search for exoplanets around M dwarfs: Different roads to radii and masses of the target starsApr 05 2019We determine the radii and masses of 293 nearby, bright M dwarfs of the CARMENES survey. This is the first time that such a large and homogeneous high-resolution (R>80 000) spectroscopic survey has been used to derive these fundamental stellar parameters. ... More
Ultraviolet Spectropolarimetry as a Tool for Understanding the Diversity of Exoplanetary AtmospheresMar 14 2019The polarization state of starlight reflected by a planetary atmosphere uniquely reveals coverage, particle size, and composition of aerosols as well as changing cloud patterns. It is not possible to obtain a comparable level of detailed from flux-only ... More
No-Free-Lunch Theorems in the continuumSep 07 2014Oct 16 2014No-Free-Lunch Theorems state, roughly speaking, that the performance of all search algorithms is the same when averaged over all possible objective functions. This fact was precisely formulated for the first time in a now famous paper by Wolpert and Macready, ... More
|Vub| from Exclusive Semileptonic B to pi DecaysMar 27 2007May 17 2007We use Omnes representations of the form factors f_+ and f_0 for exclusive semileptonic B to pi decays, paying special attention to the treatment of the B* pole and its effect on f_+. We apply them to combine experimental partial branching fraction information ... More
Form Factors for Semileptonic B -> pi and D -> pi Decays from the Omnes RepresentationJul 24 2000Feb 27 2001We use the Omnes representation to obtain the q-squared dependence of the form factors f+ and f0 for semileptonic H -> pi decays from the elastic pi H -> pi H scattering amplitudes, where H denotes a B or D meson. The scattering amplitudes used satisfy ... More
Deriving the existence of $B\bar{B}^*$ bound states from the X(3872) and Heavy Quark SymmetryJun 03 2011Aug 31 2011We discuss the possibility and the description of bound states between $B$ and $\bar{B}^*$ mesons. We argue that the existence of such a bound state can be deduced from (i) the weakly bound X(3872) state, (ii) certain assumptions about the short range ... More
Stellar Wind Variations During the X-ray High and Low States of Cygnus X-1Jan 28 2008We present results from Hubble Space Telescope UV spectroscopy of the massive X-ray binary system, HD226868 = Cyg X-1. The spectra were obtained at both orbital conjunction phases in two separate runs in 2002 and 2003 when the system was in the X-ray ... More
Torus model properties of an ultra-hard X-ray selected sample of Seyfert galaxiesApr 07 2019We characterize for the first time the torus properties of an ultra-hard X-ray (14-195 keV) volume-limited (DL<40 Mpc) sample of 24 Seyfert (Sy) galaxies (BCS40 sample). The sample was selected from the Swift/BAT nine month catalog. We use high angular ... More
The Survey for Ionization in Neutral-Gas Galaxies: III. Diffuse, Warm Ionized Medium and Escape of Ionizing RadiationMar 01 2007We use the first data release from the SINGG H-alpha survey of HI-selected galaxies to study the quantitative behavior of the diffuse, warm ionized medium (WIM) across the range of properties represented by these 109 galaxies. The mean fraction f_WIM ... More
The Ultraviolet Spectrum and Physical Properties of the Mass Donor Star in HD 226868 = Cygnus X-1Jul 14 2009We present an examination of high resolution, ultraviolet spectroscopy from Hubble Space Telescope of the photospheric spectrum of the O-supergiant in the massive X-ray binary HD 226868 = Cyg X-1. We analyzed this and ground-based optical spectra to determine ... More
J-PLUS: Discovery and characterisation of ultracool dwarfs using Virtual Observatory toolsMay 08 2019May 13 2019Ultracool dwarfs (UCDs) are objects with spectral types equal or later than M7. Most of them have been discovered using wide-field imaging surveys. The Virtual Observatory (VO) has proven to be of great utility to efficiently exploit these astronomical ... More
ASAS Light Curves of Intermediate Mass Eclipsing Binaries and the Parameters of HI MonApr 15 2011We present a catalog of 56 candidate intermediate mass eclipsing binary systems extracted from the 3rd data release of the All Sky Automated Survey. We gather pertinent observational data and derive orbital properties, including ephemerides, for these ... More
Resolved Dust Emission in a Quasar at z=3.65May 15 2009We present submillimetre observations of the z=3.653 quasar SDSS160705+533558 together with data in the optical and infrared. The object is unusually bright in the far-IR and submm with an IR luminosity of ~10^14 L_sun. We ascribe this luminosity to a ... More
Black holes and a scalar field in an expanding universeJun 16 2000Nov 14 2000We consider a model of an inhomogeneous universe including a massless scalar field, where the inhomogeneity is assumed to consist of many black holes. This model can be constructed by following Lindquist and Wheeler, which has already been investigated ... More
Black Hole in Higher Curvature Gravity and AdS/CFT CorrespondenceNov 27 2000The classical central charge for the higher curvature gravity in 3-dimensions is calculated using the Legendre transformation method. The statistical entropy of BTZ black hole is derived by the Cardy's formula and the result completely coincides with ... More
Agler-Commutant Lifting on an AnnulusJan 26 2012The main result is a test function style commutant lifting theorem for an annulus A. The test functions are the minimal inner functions for A. The model space is the Sarason Hardy Hilbert space for A uniquely determined by the fact that its reproducing ... More
Statistical Entropy of BTZ Black Hole in Higher Curvature GravitySep 21 1999Nov 12 1999For the BTZ black hole in the Einstein gravity, a statistical entropy has been calculated to be equal to the Bekenstein-Hawking entropy. In this paper, the statistical entropy of the BTZ black hole in the higher curvature gravity is calculated and shown ... More
Theoretical uncertainties on quasielastic charged-current neutrino-nucleus cross sectionsApr 05 2006May 20 2006We estimate the theoretical uncertainties of the model developed in Phys. Rev. C70 055503 for inclusive quasielastic charged-current neutrino-nucleus reactions at intermediate energies. Besides we quantify the deviations of the predictions of this many ... More
Coherent pion production off nuclei at T2K and MiniBooNE energies revisitedJul 21 2010Oct 15 2010As a result of a new improved fit to old bubble chamber data of the dominant axial C_5^A nucleon-to-Delta form factor, and due to the relevance of this form factor for neutrino induced coherent pion production, we re-evaluate our model predictions in ... More
Chiral Symmetry and Neutrino Pion Production off the NucleonOct 30 2007The neutrino pion production off the nucleon is traditionally described in the literature by means of the weak excitation of the Delta(1232) resonance and its subsequent decay into N pi. Here, we present results from a model that includes also some background ... More
BTZ Black Hole Entropy in Higher Curvature GravityJan 07 2000Jan 10 2000For the BTZ black hole in the Einstein gravity, a statistical entropy has been calculated. It is equal to the Bekenstein-Hawking entropy. In this article, its statistical entropy in the higer curvature gravity is calculated and shown to be equal to one ... More
J-PLUS: Identification of low-metallicity stars with artificial neural networks using SPHINXNov 06 2018We present a new methodology for the estimation of stellar atmospheric parameters from narrow- and intermediate-band photometry of the Javalambre Photometric Local Universe Survey (J-PLUS), and propose a method for target pre-selection of low-metallicity ... More
Quasi-Elastic Neutrino-Nucleus ReactionsFeb 06 2006The quasi-elastic contribution of the nuclear inclusive electron scattering model developed in A. Gil, J. Nieves, and E. Oset: Nucl. Phys. A 627 (1997) 543; is extended to the study of electroweak Charged Current (CC) induced nuclear reactions at intermediate ... More
Pion Production in Neutrino-Nucleon ReactionsSep 05 2007We construct a model for the weak pion production off the nucleon, which in addition to the weak excitation of the $\Delta(1232)$ resonance and its subsequent decay into $N\pi$, it includes also some background terms required by chiral symmetry. We re-fit ... More
Inclusive Quasi-Elastic Charged-Current Neutrino-Nucleus ReactionsAug 01 2004Oct 05 2004The Quasi-Elastic (QE) contribution of the nuclear inclusive electron scattering model developed in Nucl. Phys. A627 (1997) 543 is extended to the study of electroweak Charged Current (CC) induced nuclear reactions, at intermediate energies of interest ... More
Triply Heavy Baryons and Heavy Quark Spin SymmetryOct 13 2011Jan 11 2012We study the semileptonic $b\to c$ decays of the lowest-lying triply-heavy baryons made from $b$ and $c$ quarks in the limit $m_b, m_c \gg \Lambda_\mathrm{QCD}$ and close to the zero recoil point. The separate heavy quark spin symmetries strongly constrain ... More
Semileptonic bc to cc and bb to bc Baryon Decays and Heavy Quark Spin SymmetryDec 11 2009We study the semileptonic decays of the lowest-lying $bc$ baryons to the lowest-lying $cc$ baryons ($\Xi_{bc}^{(\prime*)}\to \Xi_{cc}^{(*)}$ and $\Omega_{bc}^{(\prime*)}\to \Omega_{cc}^{(*)}$), in the limit $m_b, m_c \gg \Lambda_\mathrm{QCD}$ and close ... More
Ground-based detection of an extended helium atmosphere in the Saturn-mass exoplanet WASP-69bDec 07 2018Hot gas giant exoplanets can lose part of their atmosphere due to strong stellar irradiation, affecting their physical and chemical evolution. Studies of atmospheric escape from exoplanets have mostly relied on space-based observations of the hydrogen ... More
$Z_c(3900)$: Confronting theory and lattice simulationsJun 09 2016We consider a recent $T$-matrix analysis by Albaladejo {\it et al.}, [Phys.\ Lett.\ B {\bf 755}, 337 (2016)] which accounts for the $J/\psi\pi$ and $D^\ast\bar{D}$ coupled--channels dynamics, and that successfully describes the experimental information ... More
Weak Pion Production off the NucleonJan 18 2007Jun 19 2007We develop a model for the weak pion production off the nucleon, which besides the Delta pole mechanism (weak excitation of the $\Delta(1232)$ resonance and its subsequent decay into $N\pi$), includes also some background terms required by chiral symmetry. ... More