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Uniqueness and non-existence of minimal submanifoldsJun 21 2016We provide uniqueness results for compact minimal submanifolds in a large class of Riemannian manifolds of arbitrary dimension. In the case compact and Cartan-Hadamard manifolds we obtain general results for these submanifolds. Several applications to ... More

On uniqueness of the foliation by comoving observers restspaces of a Generalized Robertson Walker spacetimeFeb 23 2019A characterization of the foliation by spacelike slices of an $(n+1)$-dimensional spatially closed Generalized Robertson-Walker spacetime is given by means of studying a natural mean curvature type equation on spacelike graphs. Under some natural assumptions, ... More

Uniqueness of complete maximal hypersurfaces in spatially open $(n+1)$-dimensional Robertson-Walker spacetimes with flat fiberMay 10 2016In this paper, under natural geometric and physical assumptions we provide new uniqueness and non-existence results for complete maximal hypersurfaces in spatially open Robertson-Walker spacetimes whose fiber is flat. Moreover, our results are applied ... More

High-Harmonic generation from spin-polarised defects in solidsJun 24 2019Generation of high-order harmonics in gases enabled to probe the attosecond electron dynamics in atoms and molecules with unprecedented resolution. Extending the techniques developed originally for atomic and molecular gases to solid state materials requires ... More

Self-propelled Vicsek particles at low speed and low densityOct 04 2018We study through numerical simulation the Vicsek model for very low speeds and densities. We consider scalar noise in 2-d and 3-d, and vector noise in 3-d. We focus on the behavior of the critical noise with density and speed, trying to clarify seemingly ... More

On maximal hypersurfaces in Lorentz manifolds admitting a parallel lightlike vector fieldApr 28 2016We study constant mean curvature spacelike hypersurfaces and in particular maximal hypersurfaces immersed in pp-wave spacetimes satisfying the timelike convergence condition. We prove the non-existence of compact spacelike hypersurfaces whose constant ... More

12CO and 13CO J=3-2 observations toward N11 in the Large Magellanic CloudMay 21 2019After 30 Doradus, N11 is the second largest and brightest nebula in the LMC. This large nebula has several OB associations with bright nebulae at its surroundings. N11 was previously mapped at the lowest rotational transitions of $^{12}$CO (J=1--0 and ... More

Hamiltonian optics of hyperbolic polaritons in nanogranulesFeb 23 2015May 22 2015Semiclassical quantization rules and numerical calculations are applied to study polariton modes of materials whose permittivity tensor has principal values of opposite sign (so-called hyperbolic materials). The spectra of volume- and surface-confined ... More

Diffusion of solar magnetic elements up to supergranular spatial and temporal scalesMay 17 2013May 24 2013The study of spatial and temporal scales on which small magnetic structures (magnetic elements) are organized in the quiet Sun may be approached by determining how they are transported on the solar photosphere by convective motions. The process involved ... More

Light-induced anomalous Hall effect in massless Dirac fermion systems and topological insulators with dissipationMay 30 2019Employing the quantum Liouville equation with phenomenological dissipation, we investigate the transport properties of massless and massive Dirac fermion systems that mimics graphene and topological insulators, respectively. The massless Dirac fermion ... More

Complete constant mean curvature spacelike hypersurfaces in the Einstein-de Sitter spacetimeJan 03 2014Uniqueness and non-existence results on complete constant mean curvature spacelike hypersurfaces lying between two spacelike slice in the Einstein-de Sitter spacetime are given. They are obtained from a Liouvielle-type theorem applied to a distinguished ... More

Transient charge and energy flow in the wide-band limitJan 25 2018The wide-band limit is a commonly used approximation to analyze transport through nanoscale devices. In this work we investigate its applicability to the study of charge and heat transport through molecular break junctions exposed to voltage biases and ... More

Multi-flat bands and strong correlations in Twisted Bilayer Boron NitrideDec 19 2018In a groundbreaking experimental advance it was recently shown that by stacking two sheets of graphene atop of each other at a twist angle close to one of the so called "magic angles", an effective two-dimensional correlated system emerges. In this system ... More

Universal Optical Control of Chiral Superconductors and Majorana ModesOct 15 2018May 29 2019Chiral superconductors are a novel class of unconventional superconductors that host topologically protected chiral Majorana fermions at interfaces and domain walls, elusive quasiparticles that could serve as a platform for topological quantum computing. ... More

Millimeter and far-IR study of the IRCD SDC 341.232-0.268Jul 10 2019We analyze the molecular gas and dust associated with the infrared dark cloud SDC 341.232-0.268 in order to investigate the characteristics and parameters of the gas, determine the evolutionary status of four embedded EGO candidates and establish possible ... More

Pair separation of magnetic elements in the quiet SunSep 03 2014Feb 13 2015The dynamic properties of the quiet Sun photosphere can be investigated by analyzing the pair dispersion of small-scale magnetic fields (i.e., magnetic elements). By using $25$ hr-long Hinode magnetograms at high spatial resolution ($0".3$), we tracked ... More

Attosecond screening dynamics mediated by electron-localizationNov 02 2018Nov 07 2018Transition metals with their densely confined and strongly coupled valence electrons are key constituents of many materials with unconventional properties, such as high-Tc superconductors, Mott insulators and transition-metal dichalcogenides. Strong electron ... More

UV Extinction Towards a Quiescent Molecular Cloud in the SMCJan 30 2012Context: The mean UV extinction law for the Small Magellanic Cloud (SMC) is usually taken as a template for low-metallicity galaxies. However, its current derivation is based on only five stars, thus placing doubts on its universality. An increase in ... More

A dual rigidity of the sphere and the hyperbolic planeMay 20 2015There are several well-known characterizations of the sphere as a regular surface in the Euclidean space. By means of a purely synthetic technique, we get a rigidity result for the sphere without any curvature conditions, nor completeness or compactness. ... More

Emergent scale symmetry: Connecting inflation and dark energyMay 01 2017Sep 14 2017Quantum gravity computations suggest the existence of an ultraviolet and an infrared fixed point where quantum scale invariance emerges as an exact symmetry. We discuss a particular variable gravity model for the crossover between these fixed points which ... More

Calibration of the length of a chain of single gold atomsFeb 20 2002Aug 19 2002Using a scanning tunneling microscope or mechanically controllable break junctions it has been shown that it is possible to control the formation of a wire made of single gold atoms. In these experiments an interatomic distance between atoms in the chain ... More

Characterizations of umbilic points of isometric immersions in Riemannian and Lorentzian manifoldsDec 03 2015May 12 2016Several characterizations of umbilic points of submanifolds in arbitrary Riemannian and Lorentzian manifolds are given. As a consequence, we obtain new characterizations of spheres in the Euclidean space and of hyperbolic spaces in the Lorentz-Minkowski ... More

Complete colorings of planar graphsJun 09 2017Apr 06 2018In this paper, we study the achromatic and the pseudoachromatic numbers of planar and outerplanar graphs as well as planar graphs of girth 4 and graphs embedded on a surface. We give asymptotically tight results and lower bounds for maximal embedded graphs. ... More

The nonlinear states of viscous capillary jets confined in the axial directionFeb 23 2018We report an experimental and theoretical study of the global stability and nonlinear dynamics of vertical jets of viscous liquid confined in the axial direction due to their impact on a bath of the same liquid. Previous works demonstrated that in the ... More

Compact spacelike surfaces whose mean curvature function satisfies a nonlinear inequality in a 3-dimensional Generalized Robertson-Walker spacetimeSep 06 2014Spacelike surfaces in Generalized Robertson-Walker spacetimes whose mean curvature function satisfies a natural nonlinear inequality are analyzed. Several uniqueness and nonexistence results for such compact spacelike surfaces are proved. In the nonparametric ... More

Deep learning techniques applied to the physics of extensive air showersJul 24 2018Apr 04 2019Deep neural networks are a powerful technique that have found ample applications in several branches of Physics. In this work, we apply machine learning algorithms to a specific problem of Cosmic Ray Physics: the estimation of the muon content of extensive ... More

Microscopic theory for the light-induced anomalous Hall effect in grapheneMay 11 2019We employ a quantum Liouville equation with relaxation to model the recently observed anomalous Hall effect in graphene irradiated by an ultrafast pulse of circularly polarized light. In the weak-field regime, we demonstrate that the Hall effect originates ... More

Vibron-assisted spin excitation in a magnetically anisotropic nickelocene complexJun 03 2019The ability to electrically-drive spin excitations in molecules with magnetic anisotropy is key for high-density storage and quantum-information technology. Electrons, however, also tunnel via the vibrational excitations unique to a molecule. The interplay ... More

Orbital-selective spin excitation of a magnetic porphyrinAug 03 2017Jan 29 2018Scattering of electrons by localized spins is the ultimate process enabling electrical detection and control of the magnetic state of a spin-doped material. At the molecular scale, this scattering is mediated by the electronic orbitals hosting the spin. ... More

On crossing families of complete geometric graphsMay 24 2018Aug 15 2018A crossing family is a collection of pairwise crossing segments, this concept was introduced by Aronov et. al. (1994). They prove that any set of $n$ points (in general position) in the plain contains a crossing family of size $\sqrt{n/12}$. In this paper ... More

Exact exchange-correlation potential of effectively interacting Kohn-Sham systemsJun 29 2019Aiming to combine density functional theory (DFT) and wavefunction theory, we study a mapping from the many-body interacting system to an effectively-interacting Kohn-Sham system instead of a non-interacting Kohn-Sham system. Because a ground state of ... More

Flexible linear mixed models with improper priors for longitudinal and survival dataSep 19 2016We propose a Bayesian approach using improper priors for hierarchical linear mixed models with flexible random effects and residual error distributions. The error distribution is modelled using scale mixtures of normals, which can capture tails heavier ... More

Scalar curvature of spacelike hypersurfaces and certain class of cosmological models for accelerated expanding universesNov 04 2015We study the scalar curvature of spacelike hypersurfaces in the family of cosmological models known as generalized Robertson-Walker spacetimes, and give several rigidity results under appropriate mathematical and physical assumptions. On the other hand, ... More

Solution of Poisson's equation for finite systems using plane wave methodsDec 12 2000Reciprocal space methods for solving Poisson's equation for finite charge distributions are investigated. Improvements to previous proposals are presented, and their performance is compared in the context of a real-space density functional theory code. ... More

A Model for Damage Spreading with Damage Healing: Monte Carlo Study of the two Dimensional Ising FerromagnetMay 30 2007An Ising model for damage spreading with a probability of damage healing ($q = 1 - p$) is proposed and studied by means of Monte Carlo simulations. In the limit $p \to 1$ the new model is mapped to the standard Ising model. It is found that, for temperatures ... More

Markov Chain Monte Carlo with the Integrated Nested Laplace ApproximationJan 26 2017Apr 05 2017The Integrated Nested Laplace Approximation (INLA) has established itself as a widely used method for approximate inference on Bayesian hierarchical models which can be represented as a latent Gaussian model (LGM). INLA is based on producing an accurate ... More

Bayesian modelling of skewness and kurtosis with two-piece scale and shape distributionsJun 30 2014Aug 06 2015We formalise and generalise the definition of the family of univariate double two--piece distributions, obtained by using a density--based transformation of unimodal symmetric continuous distributions with a shape parameter. The resulting distributions ... More

Short-Time Critical Dynamics of Damage Spreading in the Two-Dimensional Ising ModelMay 10 2010The short-time critical dynamics of propagation of damage in the Ising ferromagnet in two dimensions is studied by means of Monte Carlo simulations. Starting with equilibrium configurations at $T= \infty$ and magnetization $M=0$, an initial damage is ... More

Discovery of a dense molecular cloud towards a young massive embedded star in 30 DoradusJun 29 2009The 30 Doradus region in the Large Magellanic Cloud is one of the most outstanding star forming regions of the Local Group and a primary target to study star formation in an environment of low metallicity. In order to obtain a more complete picture of ... More

The Damage Spreading Method in Monte Carlo Simulations: A brief overview and applications to confined magnetic materialsMar 11 2008In this paper we first give a brief overview of Monte Carlo simulation results obtained by applying the Damage Spreading method. We analyse the transition between a state where the damage becomes healed (the frozen phase) and a regime where the damage ... More

Study of Damage Propagation at the Interface Localization-Delocalization Transition of the Confined Ising ModelMay 30 2007The propagation of damage in a confined magnetic Ising film, with short range competing magnetic fields ($h$) acting at opposite walls, is studied by means of Monte Carlo simulations. Due to the presence of the fields, the film undergoes a wetting transition ... More

Probing magnetic interactions between Cr adatoms on the $β$-Bi$_2$Pd superconductorSep 26 2017We show that the magnetic ordering of coupled atomic dimers on a superconductor is revealed by their intra-gap spectral features. Chromium atoms on the superconductor $\beta$-Bi$_2$Pd surface display Yu-Shiba-Rusinov bound states, detected as pairs of ... More

The Friedmann cosmological models revisited as an harmonic motion and new exact solutionsFeb 28 2014A new approach for arbitrary dimension to the Friedmann cosmological models is presented. Taking suitable changes of the parameters of the spacetime the harmonic motion equations appear, where the curvature determines the angular frequency. Some physical ... More

An analytical approach to the external force-free motion of pendulums on surfaces of constant curvatureApr 23 2014The dynamics of force free motion of pendulums on surfaces of constant Gaussian curvature is addressed when the pivot moves along a geodesic obtaining the Lagragian of the system. As a application it is possible the study of elastic and quantum pendulums. ... More

A Simple Approach to Maximum Intractable Likelihood EstimationJan 03 2013Approximate Bayesian Computation (ABC) can be viewed as an analytic approximation of an intractable likelihood coupled with an elementary simulation step. Such a view, combined with a suitable instrumental prior distribution permits maximum-likelihood ... More

Damage Spreading at the Corner Filling Transition in the two-dimensional Ising ModelOct 12 2006The propagation of damage on the square Ising lattice with a corner geometry is studied by means of Monte Carlo simulations. It is found that, just at $T=T_f (h)$ (critical temperature of the filling transition) the damage initially propagates along the ... More

Local adsorption structure and bonding of porphine on Cu(111) before and after self-metalationMay 07 2019We have experimentally determined the lateral registry and geometric structure of free-base porphine (2H-P) and copper-metalated porphine (Cu-P) adsorbed on Cu(111), by means of energy-scanned photoelectron diffraction (PhD), and compared the experimental ... More

Quantum gas microscopy of Rydberg macrodimersDec 18 2018May 17 2019A microscopic understanding of molecules is essential for many fields of natural sciences but their tiny size hinders direct optical access to their constituents. Rydberg macrodimers - bound states of two highly-excited Rydberg atoms - feature bond lengths ... More

Ab initio calculations of the dynamical response of copperMar 05 1999The role of localized $d$-bands in the dynamical response of Cu is investigated, on the basis of {\em ab initio} pseudopotential calculations. The density-response function is evaluated in both the random-phase approximation (RPA) and a time-dependent ... More

Compact maximal hypersurfaces in stably causal spacetimesSep 14 2016Several uniqueness results on compact maximal hypersurfaces in a wide class of sta- bly causal spacetimes are given. They are obtained from the study of a distinguished function on the maximal hypersurface, under suitable natural first order conditions ... More

The Role of Oligomeric Gold-Thiolate Units in Single Molecule Junc-tions of Thiol-Anchored MoleculesMar 20 2018Using the break junction (BJ) technique we show that Au(RS)2 units play a significant role in thiol-terminated molecular junctions formed on gold. We have studied a range of thiol-terminated compounds, either with the sulfur atoms in direct conjugation ... More

An O(a) modified lattice set-up of the Schrödinger functional in SU(3) gauge theoryApr 30 2011Jan 18 2012The set-up of the QCD Schr\"odinger functional (SF) on the lattice with staggered quarks requires an even number of points $L/a$ in the spatial directions, while the Euclidean time extent of the lattice, $T/a$, must be odd. Identifying a unique renormalisation ... More

Pervasive Linear Polarization Signals in the Quiet SunJul 03 2012Sep 02 2012This paper investigates the distribution of linear polarization signals in the quiet Sun internetwork using ultra-deep spectropolarimetric data. We reduce the noise of the observations as much as is feasible by adding single-slit measurements of the Zeeman-sensitive ... More

Spectral-weight function of the ionic Hubbard modelOct 21 2002The one-electron spectral-weight function of the half-filled ionic Hubbard model is calculated by means of Quantum Monte Carlo. A metallic regimen occurs between two values of the coupling constant (Hubbard U) U1 < U2 . The system is a band insulator ... More

Natural (non-)informative priors for skew-symmetric distributionsMay 10 2016In this paper, we present an innovative method for constructing proper priors for the skewness parameter in the skew-symmetric family of distributions. The proposed method is based on assigning a prior distribution on the perturbation effect of the skewness ... More

Higgs bundles, the Toledo invariant and the Cayley correspondenceNov 24 2015Jun 01 2017We define the Toledo invariant of a G-Higgs bundle on a Riemann surface, where G is a real semisimple group of Hermitian type, and we prove a Milnor-Wood type bound for this invariant when the bundle is semistable. We prove rigidity results when the Toledo ... More

The Magellanic Bridge cluster NGC 796: Deep optical AO imaging reveals the stellar content and initial mass function of a massive open clusterJan 04 2018NGC 796 is a massive young cluster located 59 kpc from us in the diffuse intergalactic medium of the 1/5-1/10 $Z_{\odot}$ Magellanic Bridge, allowing to probe variations in star formation and stellar evolution processes as a function of metallicity in ... More

The one-electron Green's function of the half-filled Hubbard model on a triangular latticeMar 22 2001The one-electron density of states for the half-filled Hubbard model on a triangular lattice is studied as a function of both temperature and Hubbard U using Quantum Monte Carlo. We find three regimes: (1) a strong-coupling Mott-Hubbard regime, characterized ... More

Mimicking alternatives to inflation with interacting spectator fieldsNov 20 2018Jan 28 2019It has been argued that oscillatory features from spectator fields in the primordial power spectrum could be a probe of alternatives to inflation. In this work, we soften this claim by showing that the frequency and amplitude dependence of the patterns ... More

On the robustness of the primordial power spectrum in renormalized Higgs inflationJun 15 2017Feb 21 2018We study the cosmological consequences of higher-dimensional operators respecting the asymptotic symmetries of the tree-level Higgs inflation action. The main contribution of these operators to the renormalization group enhanced potential is localized ... More

On the Lie algebra structure of $HH^1(A)$ of a finite-dimensional algebra $A$Mar 20 2019Mar 22 2019Let $A$ be a split finite-dimensional associative unital algebra over a field. The first main result of this note shows that if the Ext-quiver of $A$ is a simple directed graph, then $HH^1(A)$ is a solvable Lie algebra. The second main result shows that ... More

Charmed hadron spectroscopy on the lattice for $N_f=2+1$ flavoursDec 03 2012Dec 16 2012We study the spectra of charmonia, charmed mesons, singly and doubly charmed baryons using Lattice QCD, with 2+1 flavours of fermions. In the case of mesons, we include higher spin states, while for baryons, both positive and negative parity channels ... More

Nonadiabatic \textit{ab initio} Quantum Dynamics without Potential Energy SurfacesMay 28 2018We present an efficient \textit{ab initio} algorithm for quantum dynamics simulations of interacting systems that is based on the conditional decomposition of the many-body wavefunction [Phys. Rev. Lett. 113, 083003 (2014)]. Starting with this formally ... More

The role of occupied d states in the relaxation of hot electrons in AuMay 03 2000We present first-principles calculations of electron-electron scattering rates of low-energy electrons in Au. Our full band-structure calculations indicate that a major contribution from occupied d states participating in the screening of electron-electron ... More

Study of the molecular gas towards the N11 region in the Large Magellanic CloudJul 12 2018We study three subregions in the HII region N11 which is located at the northeast side of the Large Magellanic Cloud (LMC). We used $^{12}$CO and $^{13}$CO J=3--2 data observed with the Atacama Submillimeter Telescope Experiment (ASTE) with an angular ... More

A molecular outflow evidencing star formation activity in the vicinity of the HII region G034.8-0.7 and the SNR W44Feb 13 2009This work aims at investigating the molecular gas component in the vicinity of two young stellar object (YSO) candidates identified at the border of the HII region G034.8-0.7 that is evolving within a molecular cloud shocked by the SNR W44. The purpose ... More

Block algebras with HH1 a simple Lie algebraNov 25 2016We show that if $B$ is a block of a finite group algebra $kG$ over an algebraically closed field $k$ of prime characteristic $p$ such that $\HH^1(B)$ is a simple Lie algebra and such that $B$ has a unique isomorphism class of simple modules, then $B$ ... More

Coloring decompositions of complete geometric graphsOct 05 2016Mar 21 2019A decomposition of a non-empty simple graph $G$ is a pair $[G,P]$, such that $P$ is a set of non-empty induced subgraphs of $G$, and every edge of $G$ belongs to exactly one subgraph in $P$. The chromatic index $\chi'([G,P])$ of a decomposition $[G,P]$ ... More

On the ill posedness of Force-Free Electrodynamics in Euler PotentialsNov 19 2016Feb 17 2017We prove that the initial value problem for Force-free Electrodynamics in Euler variables is not well posed. We establish this result by showing that a well-posedness criterion provided by Kreiss fails to hold for this theory, and using a theorem provided ... More

Charmed baryon spectroscopy and light flavour symmetry from lattice QCDMar 29 2015Aug 13 2015We determine the ground state and first excited state masses of singly and doubly charmed spin 1/2 and 3/2 baryons with positive and negative parity. Configurations with $N_f=2+1$ non-perturbatively improved Wilson-clover fermions were employed, with ... More

Quantum Interference and Decoherence in Single-Molecule Junctions: How Vibrations Induce Electrical CurrentFeb 21 2011Quantum interference effects and decoherence mechanisms in single-molecule junctions are analyzed employing a nonequilibrium Green's function approach. Electrons tunneling through quasi-degenerate states of a nanoscale molecular junction exhibit interference ... More

Discovering a misaligned CO outflow related to the red MSX source G034.5964-01.0292Jun 10 2014The red MSX source G034.5964-01.0292 (MSXG34), catalogued as a massive YSO, was observed in molecular lines with the aim of discover and study molecular outflows. We mapped a region of 3'x3' centered at MSXG34 using the Atacama Submillimeter Telescope ... More

Visualization of multifractal superconductivity in a two-dimensional transition metal dichalcogenide in the weak-disorder regimeOct 18 2018Jun 23 2019Eigenstate multifractality is a distinctive feature of non-interacting disordered metals close to a metal-insulator transition, whose properties are expected to extend to superconductivity. While multifractality in three dimensions (3D) only develops ... More

A New Twist in the Realization of One-Dimensional PhysicsMay 10 2019Experimental advances in the fabrication and characterization of few-layer materials stacked at a relative twist of small angle have recently shown the emergence of flat energy bands [1-5]. As a consequence electron-interactions become relevant, providing ... More

High resolution CO observations towards the Bright Eastern Knot of the SNR Puppis AJan 02 2008This paper reports molecular observations towards the Bright Eastern Knot (BEK) in the SNR Puppis A, a feature where radio and X-ray studies suggest that the shock front is interacting with a dense molecular clump. We performed high-resolution millimetric ... More

Fluxtube model atmospheres and Stokes V zero-crossing wavelengthsJan 13 1997First results of the inversion of Stokes I and V profiles from plage regions near disk center are presented. Both low and high spatial resolution spectra of FeI 6301.5 and FeI 6302.5 A obtained with the Advanced Stokes Polarimeter (ASP) have been considered ... More

Complete Spacelike Hypersurfaces in Generalized Robertson-Walker and the Null Convergence Condition. Calabi-Bernstein problemsFeb 28 2015We study constant mean curvature spacelike hypersurfaces in generalized Robertson-Walker spacetimes which are spatially parabolic covered (i.e. its fiber F is a (non- compact) complete Riemannian manifold whose universal covering is parabolic) and satisfy ... More

Millimeter dust continuum emission unveiling the true mass of giant molecular clouds in the Small Magellanic CloudApr 24 2007CO observations have been so far the best way to trace molecular gas in external galaxies, but at low metallicity the gas mass deduced could be largely underestimated. At present, the kinematic information of CO data cubes are used to estimate virial ... More

Intramolecular distances and form factor of cyclic chains with excluded volume interactionsNov 07 2007Numerical simulations are performed for isolated cyclic chains with excluded volume. Data are reported for the form factor, S(x), where x is the reduced scattering variable, and also for averages and distributions of the distance between intramolecular ... More

Massive young stellar objects in the N66/NGC346 region of the SMCMar 28 2018We present HK spectra of three sources located in the N66 region of the Small Magellanic Cloud. The sources display prominent stellar Br Gamma and extended H2 emission, and exhibit infrared excesses at lambda > 2 micron. Based on their spectral features, ... More

A study on Ca II 854.2 nm emission in a sunspot umbra using a thin cloud modelDec 20 2016In the present work, we introduce and explain a method of solution of the radiative transfer equation based on a thin cloud model. The efficiency of this method to retrieve dynamical chromospheric parameters from Stokes I profiles of Ca II 854.2 nm line ... More

Damage Spreading in a Driven Lattice Gas ModelAug 29 2012We studied damage spreading in a Driven Lattice Gas (DLG) model as a function of the temperature $T$, the magnitude of the external driving field $E$, and the lattice size. The DLG model undergoes an order-disorder second-order phase transition at the ... More

Coupling of excitons and defect states in boron-nitride nanostructuresMar 14 2011The signature of defects in the optical spectra of hexagonal boron nitride (BN) is investigated using many body perturbation theory. A single BN-sheet serves as a model for different layered BN- nanostructures and crystals. In the sheet we embed prototypical ... More

Constant mean curvature spacelike hypersurfaces in Lorentzian warped products and Calabi-Bernstein type problemsJan 28 2014In this paper we provide several uniqueness and non-existence results for complete parabolic constant mean curvature spacelike hypersurfaces in Lorentzian warped products under appropriate geometric assumptions. As a consequence of this parametric study, ... More

Deformations and Thermal Stability of Carbon Nanotube RopesMar 31 2003Structural and thermal characteristics of crystalline ropes of single-wall carbon nanotubes (SWCNTs) are investigated. Novel crystalline ropes of polygonized SWCNTs produced by laser irradiation exhibit rounded-hexagonal cross sections in contrast to ... More

Light-matter interaction in the long-wavelength limit: no ground-state without dipole self-energyJul 10 2018Most theoretical studies for correlated light-matter systems are performed within the long-wavelength limit, i.e., the electromagnetic field is assumed to be spatially uniform. In this limit the so-called length-gauge transformation for a fully quantized ... More

Light-Matter Interactions via the Exact Factorization ApproachMar 06 2018May 03 2018The exact factorization approach, originally developed for electron-nuclear dynamics, is extended to light-matter interactions within the dipole approximation. This allows for a Schrodinger equation for the photonic wavefunction, in which the potential ... More

Truncation Error Estimation in the p-Anisotropic Discontinuous Galerkin Spectral Element MethodJun 21 2018In the context of Discontinuous Galerkin Spectral Element Methods (DGSEM), $\tau$-estimation has been successfully used for p-adaptation algorithms. This method estimates the truncation error of representations with different polynomial orders using the ... More

Study of the molecular clump associated with the high-energy source HESS J1858+020Mar 29 2011HESS J1858+020 is a weak gamma-ray source lying near the southern border of the SNR G35.6-0.4. A molecular cloud, composed by two clumps, shows signs of interaction with the SNR and with a nearby extended HII region. In particular, the southernmost clump ... More

Time and energy-resolved two photon-photoemission of the Cu(100) and Cu(111) metal surfacesMar 31 2003We present calculations on energy- and time-resolved two-photon photoemission spectra of images states in Cu(100) and Cu(111) surfaces. The surface is modeled by a 1D effective potential and the states are propagated within a real-space, real-time method. ... More

Disconnected contributions to D-meson semi-leptonic decay form factorsNov 17 2011We calculate the disconnected contribution to the form factor for the semileptonic decay of a D-meson into a final state, containing a flavor singlet eta meson. We use QCDSF n_f=2+1 configurations at the flavor symmetric point m_u=m_d=m_s and the partially ... More

Electron-electron correlation in graphiteApr 20 2007Oct 19 2007The full three dimensional dispersion of the pi-bands, Fermi velocities and effective masses are measured with angle resolved photoemission spectroscopy and compared to first-principles calculations. The band structure by density-functional theory strongly ... More

Molecular gas towards G18.8+1.8Apr 17 2012This work aims at investigating the characteristics of the molecular gas associated with the nebula G18.8+1.8, linked to the Wolf-Rayet star HD168206 (WR 113), and its relation to other components of its local interstellar medium. We carried out molecular ... More

Scanning tunneling microscopy simulations of poly(3-dodecylthiophene) chains adsorbed on highly oriented pyrolytic graphiteJan 23 2006We report on a novel scheme to perform efficient simulations of Scanning Tunneling Microscopy (STM) of molecules weakly bonded to surfaces. Calculations are based on a tight binding (TB) technique including self-consistency for the molecule to predict ... More

Assessment of exchange-correlation functionals for the calculation of dynamical properties of small clusters in TDDFTFeb 13 2001Jun 07 2001We present a detailed study of different exchange-correlation (xc) functionals in describing the dynamical properties of finite systems. For that purpose, we calculated the static polarizabilities, ionization potentials and optical absorption spectrum ... More

Morphology of anisotropic chains in a magneto-rheological fluid during aggregation and disaggregation processesJan 11 2007Aug 19 2014We study the morphology of the chain-like aggregates formed when a external constant and uniaxial magnetic field is applied to a magneto-rheological (MR) fluid. In order to characterize the conformation of the aggregates, we study the evolution of various ... More

Emergence of small-scale magnetic loops through the quiet solar atmosphereMay 18 2009We investigate the emergence of magnetic flux in the quiet Sun at very small spatial scales, focusing on the magnetic connection between the photosphere and chromosphere. The observational data consist of spectropolarimetric measurements and filtergrams ... More

Dressed-Orbital Approach to Cavity Quantum Electrodynamics and BeyondDec 02 2018We present a novel representation of coupled matter-photon systems that allows the application of any many-body method developed for purely fermionic systems. We do so by rewriting the original coupled light-matter problem in a higher-dimensional configuration ... More

Dynamic structure factor of goldFeb 23 2001We have investigated the role of localized {\it d} bands in the dynamical response of Au, on the basis of {\it ab initio} pseudopotential calculations. The density-response function has been evaluated in the random-phase approximation. For small momenta, ... More

Estimating Spatial Econometrics Models with Integrated Nested Laplace ApproximationMar 03 2017Integrated Nested Laplace Approximation provides a fast and effective method for marginal inference on Bayesian hierarchical models. This methodology has been implemented in the R-INLA package which permits INLA to be used from within R statistical software. ... More