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Trophic coherence determines food-web stabilityApr 30 2014Nov 24 2014Why are large, complex ecosystems stable? Both theory and simulations of current models predict the onset of instability with growing size and complexity, so for decades it has been conjectured that ecosystems must have some unidentified structural property ... More

On mapping exoplanet atmospheres with high-dispersion spectro-polarimetry. Some model predictionsFeb 03 2018Planets reflect and linearly polarize the radiation that they receive from their host stars. The emergent polarization is sensitive to aspects of the planet atmosphere such as the gas composition and the occurrence of condensates and their optical properties. ... More

Intervality and coherence in complex networksMar 11 2016Food webs -- networks of predators and prey -- have long been known to exhibit "intervality": species can generally be ordered along a single axis in such a way that the prey of any given predator tend to lie on unbroken compact intervals. Although the ... More

Postnikov Invariants of Crossed ComplexesSep 20 2004We determine the Postnikov Tower and Postnikov Invariants of a Crossed Complex in a purely algebraic way. Using the fact that Crossed Complexes are homotopy types for filtered spaces, we use the above "algebraically defined" Postnikov Tower and Postnikov ... More

Self-organized surface nanopatterning by ion beam sputteringJun 18 2007The production of nanopatterns on the surfaces of targets irradiated by ion beams at low and intermediate energies has developed during the present decade to a salient degree of control over the main pattern features. However, there is still a wide experimental ... More

Transient subdiffusion from an Ising environmentAug 03 2017Jan 08 2018We introduce a model, in which a particle performs a continuous time random walk (CTRW) coupled to an environment with Ising dynamics. The particle shows locally varying diffusivity determined by the geometrical properties of the underlying Ising environment, ... More

The influential effect of blending, bump, changing period and eclipsing Cepheids on the Leavitt lawApr 17 2016The investigation of the non-linearity of the Leavitt law is a topic that began more than seven decades ago, when some of the studies in this field found that the Leavitt law has a break at about ten days. The goal of this work is to investigate a possible ... More

Sampling formulas involving differences in shift-invariant subspaces: a unified approachSep 12 2017Successive differences on a sequence of data help to discover some smoothness features of this data. This was one of the main reasons for rewriting the classical interpolation formula in terms of such data differences. The aim of this paper is to mimic ... More

Short-range stationary patterns and long-range disorder in an evolution equation for one-dimensional interfacesJan 23 2007A novel local evolution equation for one-dimensional interfaces is derived in the context of erosion by ion beam sputtering. We present numerical simulations of this equation which show interrupted coarsening in which an ordered cell pattern develops ... More

Non-linear ripple dynamics on amorphous surfaces patterned by ion-beam sputteringJun 18 2005May 17 2006Erosion by ion-beam sputtering (IBS) of amorphous targets at off-normal incidence frequently produces a (nanometric) rippled surface pattern, strongly resembling macroscopic ripples on aeolian sand dunes. Suitable generalization of continuum descriptions ... More

Coupling of morphology to surface transport in ion-beam irradiated surfaces. I. Oblique incidenceMay 26 2008We propose and study a continuum model for the dynamics of amorphizable surfaces undergoing ion-beam sputtering (IBS) at intermediate energies and oblique incidence. After considering the current limitations of more standard descriptions in which a single ... More

The spatial distribution of the far-infrared emission in NGC 253May 13 2002We study the far-infrared emission properties of the nearby starburst galaxy NGC 253 based on IRAS maps and an ISOPHOT map at 180 microns. Based on the analysis of the light profiles, we have been able to identify three main structural components: an ... More

Nonergodic subdiffusion from transient interactions with heterogeneous partnersJul 01 2016Mar 03 2017Spatiotemporal disorder has been recently associated to the occurrence of anomalous nonergodic diffusion of molecular components in biological systems, but the underlying microscopic mechanism is still unclear. We introduce a model in which a particle ... More

Magnetostructural coupling, magnetic ordering and cobalt spin reorientation in metallic Pr0.50Sr0.50CoO3 cobaltiteJun 16 2016In half-doped Pr0.50A0.50CoO3 metallic perovskites, the spin-lattice coupling brings about distinct magnetostructural transitions for A=Ca and A=Sr at temperatures close to 100 K. However, the ground magnetic properties of Pr0.50Sr0.50CoO3 (PSCO) strongly ... More

Theoretical study of phase transitions in Sb2S3, Bi2S3 and Sb2Se3 under compressionApr 19 2019We report a theoretical study of Sb2S3, Sb2Se3 and Bi2S3 sesquichalcogenides at hydrostatic pressures up to 60 GPa. We explore the possibility that the R-3m, C2/m, C2/c and Im-3m phases observed in sesquichalcogenides with heavier cations, viz. Bi2Se3, ... More

Understanding the Observed Evolution of the Galaxy Luminosity Function from z=6-10 in the Context of Hierarchical Structure FormationApr 05 2011Mar 15 2012Recent observations of the Lyman-break galaxy (LBG) luminosity function (LF) from z~6-10 show a steep decline in abundance with increasing redshift. However, the LF is a convolution of the mass function of dark matter halos (HMF)--which also declines ... More

Analytical Modeling of Galaxies at z>~6: Star Formation and Black Hole GrowthAug 03 2012Galaxies at z>~6 represent an important evolutionary link between the first galaxies and their modern counterparts. Modeling both the global and internal properties of these recently discovered objects can lead us to understand how they relate to even ... More

Pbca-type In2O3: the lost pressure-induced post-corundum phaseNov 26 2013Contradictory results of high-pressure studies in cubic bixbyite-type indium oxide (c-In2O3) at room temperature (RT) have motivated us to perform high-pressure powder x-ray diffraction and Raman scattering measurements in this material. On increasing ... More

uvby-beta photoelectric photometry of Cepheid starsJul 02 2010We present time-series uvby-beta photometry of 41 classical Cepheid stars. A brief discussion of the comparison between the presented data and previous photometric data has been done.

Upper atmospheres and ionospheres of planets and satellitesDec 08 2017Dec 11 2017The upper atmospheres of the planets and their satellites are more directly exposed to sunlight and solar wind particles than the surface or the deeper atmospheric layers. At the altitudes where the associated energy is deposited, the atmospheres may ... More

Why (and How) Avoid Orthogonal Procrustes in Regularized Multivariate AnalysisMay 09 2016Sep 19 2016Multivariate Analysis (MVA) comprises a family of well-known methods for feature extraction that exploit correlations among input variables of the data representation. One important property that is enjoyed by most such methods is uncorrelation among ... More

Symmetry of surface nanopatterns induced by ion-beam sputtering: the role of anisotropic surface diffusionJan 11 2016Ion Beam Sputtering (IBS) is a cost-effective technique able to produce ordered nanopatterns on the surfaces of different materials. To date, most theoretical studies of this process have focused on systems which become amorphous under irradiation, e.g. ... More

Betti numbers of the moduli space of rank 3 parabolic Higgs bundlesNov 10 2004Jun 01 2005We compute the Betti numbers of the moduli space of rank 3 parabolic Higgs bundles, using Morse theory. A key point is that certain critical submanifolds of the Morse function can be identified with moduli spaces of parabolic triples. These moduli spaces ... More

A note on the kernel of a pair of linear mapsMar 08 2016The kernel of a pair of linear systems is studied in the framework of commutative ring theory with applications to behavioral perspective of linear systems

Regular generalized sampling in T-invariant subspaces of a Hilbert spaceApr 09 2018A regular generalized sampling theory in some structured T-invariant subspaces of a Hilbert space H, where T denotes a bounded invertible operator in H, is established in this paper. This is done by walking through the most important cases which generalize ... More

Linear representations of convolutional codes over ringsJul 28 2016In this paper we extend the relation between convolutional codes and linear systems over finite fields to certain commutative rings through first order representations . We introduce the definition of rings with representations as those for which these ... More

Stationary waves and slowly moving features in the night upper clouds of VenusJul 25 2017Feb 12 2018At the cloud top level of Venus (65-70 km altitude) the atmosphere rotates 60 times faster than the underlying surface, a phenomenon known as superrotation. Whereas on Venus's dayside the cloud top motions are well determined and Venus general circulation ... More

Modeling sampling in tensor products of unitary invariant subspacesNov 10 2015Jun 28 2016The use of unitary invariant subspaces of a Hilbert space $\mathcal{H}$ is nowadays a recognized fact in the treatment of sampling problems. Indeed, shift-invariant subspaces of $L^2(\mathbb{R})$ and also periodic extensions of finite signals are remarkable ... More

Generic equations for pattern formation in evolving interfacesMay 10 2007We present a general formalism which allows us to derive the evolution equations describing one-dimensional (1D) and isotropic 2D interfacelike systems, that is based on symmetries, conservation laws, multiple scale arguments, and exploits the relevance ... More

Two-stage electron acceleration by 3D collisionless guide field magnetic reconnectionMay 02 2017Sep 09 2018We report a newly found two-stage mechanism of electron acceleration near X-lines of 3D collisionless guide-field magnetic reconnection in the non-relativistic regime typical, e.g., for stellar coronae. We found that after electrons are first pre-accelerated ... More

Kinetic turbulence in fast 3D collisionless guide-field magnetic reconnectionMay 02 2017Nov 02 2018Although turbulence has been conjectured to be important for magnetic reconnection, still very little is known about its role in collisionless plasmas. Previous attempts to quantify the effect of turbulence on reconnection usually prescribed Alfv\'enic ... More

Effective mean-field equations for cigar-shaped and disk-shaped Bose-Einstein condensatesJul 17 2007Jan 28 2008By applying the standard adiabatic approximation and using the accurate analytical expression for the corresponding local chemical potential obtained in our previous work [Phys. Rev. A \textbf{75}, 063610 (2007)] we derive an effective 1D equation that ... More

Accurate one-dimensional effective description of realistic matter-wave gap solitonsMay 27 2014Jun 17 2014We consider stationary matter-wave gap solitons realized in Bose--Einstein condensates loaded in one-dimensional (1D) optical lattices and investigate whether the effective 1D equation proposed in [Phys. Rev. A \textbf{77}, 013617 (2008)] can be a reliable ... More

Constraining the Minimum Mass of High-Redshift Galaxies and Their Contribution to the Ionization State of the IGMOct 11 2010We model the latest HST WFPC3/IR observations of > 100 galaxies at redshifts z=7-8 in terms of a hierarchical galaxy formation model with starburst activity. Our model provides a distribution of UV luminosities per dark matter halo of a given mass and ... More

Non-Maxwellian electron distribution functions due to self-generated turbulence in collisionless guide-field reconnectionAug 10 2016Non-Maxwellian electron velocity space distribution functions (EVDF) are useful signatures of plasma conditions and non-local consequences of collisionless magnetic reconnection. In the past, the evolution of the EVDFs was investigated mainly for antiparallel ... More

The Density Contrast of the Shapley SuperclusterMay 05 2008May 19 2008We calculate the density contrast of the Shapley Supercluster (SSC) based on the enhanced abundance of X-ray clusters in it using the extended Press-Schechter formalism. We derive a total SSC mass of M_tot=(4.4+-0.44)x10^{16} M_sun within a sphere of ... More

Effective one-dimensional dynamics of elongated Bose-Einstein condensatesJul 12 2008Apr 01 2009By using a variational approach in combination with the adiabatic approximation we derive a new effective 1D equation of motion for the axial dynamics of elongated condensates. For condensates with vorticity $|q|=0$ or 1, this equation coincides with ... More

Dynamical evolution of a doubly-quantized vortex imprinted in a Bose-Einstein CondensateJun 04 2006The recent experiment by Y. Shin \emph{et al.} [Phys. Rev. Lett. \textbf{93}, 160406 (2004)] on the decay of a doubly quantized vortex imprinted in $^{23}% $Na condensates is analyzed by numerically solving the Gross-Pitaevskii equation. Our results, ... More

Non-Maxwellian electron distribution functions due to self-generated turbulence in collisionless guide-field reconnectionAug 10 2016Oct 06 2016Non-Maxwellian electron velocity space distribution functions (EVDF) are useful signatures of plasma conditions and non-local consequences of collisionless magnetic reconnection. In the past, EVDFs were obtained mainly for antiparallel reconnection and ... More

Stable symmetry-protected 3D embedded solitons in Bose-Einstein condensatesJul 23 2018Embedded solitons are rare self-localized nonlinear structures that, counterintuitively, survive inside a continuous background of resonant states. While this topic has been widely studied in nonlinear optics, it has received almost no attention in the ... More

Verifying the Identity of High-Redshift Massive Galaxies Through the Clustering of Lower Mass Galaxies Around ThemNov 03 2007Jul 13 2008Massive high-redshift galaxies form in over-dense regions where the probability of forming other galaxies is also strongly enhanced. Given an observed flux of a galaxy, the inferred mass of its host halo tends to be larger as its inferred redshift increases. ... More

On the real linear polarization constant problemDec 01 2006The present paper deals with lower bounds for the norm of products of linear forms. It has been proved by J. Arias-de-Reyna \cite{ARIAS}, that %for ${\mathbb C}^n$, the so-called $n^{\rm th}$ linear polarization constant $c_n({\mathbb C}^n)$ is $n^{n/2}$, ... More

Light-Cone Distortion of the Clustering and Abundance of Massive Galaxies at High-RedshiftsNov 15 2007Mar 13 2008Observational surveys of galaxies are not trivially related to single-epoch snapshots from computer simulations. Observationally, an increase in the distance along the line-of-sight corresponds to an earlier cosmic time at which the properties of the ... More

Almost sharp nonlinear scattering in one-dimensional Born-Infeld equations arising in nonlinear ElectrodynamicsJul 09 2017Aug 28 2017We study decay of small solutions of the Born-Infeld equation in 1+1 dimensions, a quasilinear scalar field equation modeling nonlinear electromagnetism, as well as branes in String theory and minimal surfaces in Minkowski space-times. From the work of ... More

Towards a comprehensive model of Earth's disk-integrated Stokes vectorSep 30 2014A significant body of work on simulating the remote appearance of Earth-like exoplanets has been done over the last decade. The research is driven by the prospect of characterizing habitable planets beyond the Solar System in the near future. In this ... More

Calibration of semi-analytic models of galaxy formation using Particle Swarm OptimizationOct 25 2013Jan 29 2015We present a fast and accurate method to select an optimal set of parameters in semi-analytic models of galaxy formation and evolution (SAMs). Our approach compares the results of a model against a set of observables applying a stochastic technique called ... More

Strong Constraints on the Parameter Space of the MSSM from Charge and Color Breaking MinimaJul 12 1995Jul 27 1995A complete analysis of all the potentially dangerous directions in the field-space of the minimal supersymmetric standard model is carried out. They are of two types, the ones associated with the existence of charge and color breaking minima in the potential ... More

Proceedings of the Eleventh International Workshop on Developments in Computational ModelsMar 02 2016This volume contains the proceedings of DCM 2015, the 11th International Workshop on Developments in Computational Models held on October 28, 2015 in Cali, Colombia. DCM 2015 was organized as a one-day satellite event of the 12th International Colloquium ... More

Kinematic active region formation in a three-dimensional solar dynamo modelSep 24 2013We propose a phenomenological technique for modelling the emergence of active regions within a three-dimensional, kinematic dynamo framework. By imposing localised velocity perturbations, we create emergent flux-tubes out of toroidal magnetic field at ... More

Some Implications of Charge and Color Breaking in the MSSMJun 03 1996We examine some physically relevant implications of potentially dangerous charge and color breaking minima for supersymmetric models. First, we analyze the stability of the corresponding constraints with respect to variations of the initial scale for ... More

Solid flow drives surface nanopatterning by ion-beam irradiationMar 06 2012Ion Beam Sputtering (IBS) is known to produce surface nanopatterns over macroscopic areas on a wide range of materials. However, in spite of the technological potential of this route to nanostructuring, the physical process by which these surfaces self-organize ... More

Methodology for accurately assessing the quality perceived by users on 360VR contentsMay 09 2019To properly evaluate the performance of 360VR-specific encoding and transmission schemes, and particularly of the solutions based on viewport adaptation, it is necessary to consider not only the bandwidth saved, but also the quality of the portion of ... More

Video Multimethod Assessment Fusion (VMAF) on 360VR contentsJan 18 2019This paper describes the subjective experiments and subsequent analysis carried out to validate the application of one of the most robust and influential video quality metrics, Video Multimethod Assessment Fusion (VMAF), to 360VR contents. VMAF is a full ... More

Nonlinear alfvénic fast particle transport and lossesNov 16 2012Magnetohydrodynamic instabilities like Toroidal Alfv\'en Eigenmodes or core-localized modes such as Beta Induced Alfv\'en Eigenmodes and Reversed Shear Alfv\'en Eigenmodes driven by fast particles can lead to significant redistribution and losses in fusion ... More

Size Effects in the Magnetoresistance of Graphite: Absence of Magnetoresistance in Micrometer size SamplesJun 20 2007We present a study of the magnetoresistance of highly oriented pyrolytic graphite (HOPG) as a function of the sample size. Our results show unequivocally that the magnetoresistance reduces with the sample size even for samples of hundreds of micrometers ... More

An overview of the computational aspects of nonunique factorization invariantsApr 28 2015We give an overview of the existing algorithms to compute nonunique factorization invariants in finitely generated monoids.

Greedy energy points with external fieldsJan 27 2009May 27 2010In this paper we introduce several extremal sequences of points on locally compact metric spaces and study their asymptotic properties. These sequences are defined through a greedy algorithm by minimizing a certain energy functional whose expression involves ... More

A Lattice-Boltzmann method for the interaction between mechanical waves and solid mobile bodiesMay 04 2017Nov 02 2018The acoustic waves generated by moving bodies and the movement of bodies by acoustic waves are central phenomena in the operation of musical instruments and in everyday's experiences like the movement of a boat on a lake by the wake generated by a propelled ... More

Fitting the Quark and Lepton Masses in String TheoriesJun 23 1992The capability of string theories to reproduce at low energy the observed pattern of quark and lepton masses and mixing angles is examined, focusing the attention on orbifold constructions, where the magnitude of Yukawa couplings depends on the values ... More

Dependence of the physical properties of $Nd_{0.5}Ca_{0.5}MnO_{3+δ}$ on the oxydation state of $Mn$Mar 01 2000We present a comparative study of the magnetic, transport and structural properties of $Nd_{0.5}Ca_{0.5}MnO_{3+\delta}$ [$\delta=$ 0.02(1) and 0.04(1)]. We have found significant differences between the low temperature magnetic orders and the magnetization ... More

Ion-beam nanopatterning of silicon surfaces under co-deposition of non-silicide-forming impuritiesJan 11 2016We report experiments on surface nanopatterning of Si targets which are irradiated with 2 keV Ar + ions impinging at near-glancing incidence, under concurrent co-deposition of Au impurities simultaneously extracted from a gold target by the same ion beam. ... More

Photochemical hazes in sub-Neptunian atmospheres with focus on GJ 1214 bMay 08 2019We study the properties of photochemical hazes in super-Earths/mini-Neptunes atmospheres with particular focus on GJ1214b. We evaluate photochemical haze properties at different metallicities between solar and 10000$\times$solar. Within the four orders ... More

Diffusion through a network of compartments separated by partially-transmitting boundariesOct 04 2018We study the random walk of a particle in a compartmentalized environment, as realized in biological samples or solid state compounds. Each compartment is characterized by its length $L$ and the boundaries transmittance $T$. We identify two relevant spatio-temporal ... More

A Framework for Empirical Galaxy Phenomenology: The Scatter in Galaxy Ages and Stellar MetallicitiesApr 07 2014Jan 28 2015We develop a theoretical framework that extracts a deeper understanding of galaxy formation from empirically-derived relations among galaxy properties by extending the main-sequence integration method for computing galaxy star formation histories. We ... More

Vortex lines attached to dark solitons in Bose-Einstein condensates and Boson-Vortex Duality in 3+1 DimensionsJun 08 2016Dec 23 2016We demonstrate the existence of stationary states composed of vortex lines attached to planar dark solitons in scalar Bose-Einstein condensates. Dynamically stable states of this type are found at low values of the chemical potential in channeled condensates, ... More

Galaxy Statistics in Pencil-beam Surveys at High RedshiftsJun 15 2009Jan 13 2010Surveys of faint galaxies at high redshifts often result in a "pencil-beam" geometry that is much longer along the line-of-sight than across the sky. We explore the effects of this geometry on the abundance and clustering of Lyman-break galaxies (LBGs) ... More

Does Singlet Fission Enhance the Performance of Organic Solar Cells?Sep 20 2012Mar 14 2013Singlet fission, in which the optical spin-singlet exciton dissociates into two low energy triplet excitons, has been proposed as a viable approach to enhance the quantum efficiency of organic solar cells. We show that even when singlet fission is occurring ... More

A bibliometric approach to Systematic Mapping Studies: The case of the evolution and perspectives of community detection in complex networksFeb 08 2017Critical analysis of the state of the art is a necessary task when identifying new research lines worthwhile to pursue. To such an end, all the available work related to the field of interest must be taken into account. The key point is how to organize, ... More

Renormalized Theory of Infinitely Driven Lattice GasesOct 20 1999We use field theoretic renormalization group methods to study the critical behavior of a recently proposed Langevin equation for driven lattice gases under infinitely fast drive. We perform an expansion around the upper critical dimension, $d_c=4$, and ... More

Phase Structure of Systems with Multiplicative NoiseFeb 05 1996The phase diagrams and transitions of nonequilibrium systems with multiplicative noise are studied theoretically. We show the existence of both strong and weak-coupling critical behavior, of two distinct active phases, and of a nonzero range of parameter ... More

The Gardner equation and the L^2-stability of the N-soliton solution of the Korteweg-de Vries equationDec 23 2010Jan 22 2011Multi-soliton solutions of the Korteweg-de Vries equation (KdV) are shown to be globally L2-stable, and asymptotically stable in the sense of Martel-Merle. The proof is surprisingly simple and combines the Gardner transform, which links the Gardner and ... More

The [CII] Deficit in LIRGs and ULIRGs is Due to High-Temperature SaturationOct 01 2015Current predictions for the line ratios from photo-dissociative regions (PDRs) in galaxies adopt theoretical models that consider only individual parcels of PDR gas each characterized by the local density and far-UV radiation field. However, these quantities ... More

Kinematic solar dynamo models with a deep meridional flowFeb 04 2004We develop two different solar dynamo models to verify the hypothesis that a deep meridional flow can restrict the apperance of sunspots below 45 degrees, proposed by Nandy & Choudhuri (2002). In the first one, a single polytropic approximation for the ... More

Systems with Multiplicative Noise: Critical Behavior from KPZ Equation and NumericsAug 13 1996We show that certain critical exponents of systems with multiplicative noise can be obtained from exponents of the KPZ equation. Numerical simulations in 1d confirm this prediction, and yield other exponents of the multiplicative noise problem. The numerics ... More

Limited role of spatial self-structuring in emergent trade-offs during pathogen evolutionApr 23 2018Pathogen transmission and virulence are main evolutionary variables broadly assumed to be linked through trade-offs. In well-mixed populations, these trade-offs are often ascribed to physiological restrictions, while populations with spatial self-structuring ... More

Molecular Cloud Properties and CO Line Emission in z >~ 6 GalaxiesJan 03 2013Aug 01 2013We explore molecular cloud properties and the physics of CO transition lines in z >~ 6 Lyman-break galaxies and predict their CO fluxes using an analytic formalism built from global models of star formation in high-redshift galaxies that minimizes our ... More

Extreme Galaxies During Reionization: Testing ISM and Disk ModelsSep 25 2013Dec 10 2013We test the ability of equilibrium galactic disk and one-zone interstellar medium models to describe the physical and emission properties of quasar hosts, submillimeter galaxies, and Lyman-alpha emitters at z>~6. The size, line widths, star formation ... More

Turbulent transport in 2D collisionless guide field reconnectionOct 14 2016Feb 13 2017Transport in collisionless plasmas is usually called anomalous, being due to the interaction between the particles and the self-generated turbulence by their collective interactions. Because of its relevance for astrophysical and space plasmas, we explore ... More

Instabilities of collisionless current sheets revisited: the role of anisotropic heatingJan 24 2015In this work, we investigate the influence of the anisotropic heating on the spontaneous instability and evolution of thin Harris-type collisionless current sheets, embedded in antiparallel magnetic fields. In particular, we explore the influence of the ... More

Complete structure of Z_n Yukawa couplingsOct 21 1991We give the complete twisted Yukawa couplings for all the Z_n orbifold constructions in the most general case, i.e. when orbifold deformations are considered. This includes a certain number of tasks. Namely, determination of the allowed couplings, calculation ... More

Impact of environmental colored noise in single-species population dynamicsJul 12 2017Oct 02 2017Variability on external conditions has important consequences for the dynamics and the organization of biological systems. In many cases, the characteristic timescale of environmental changes as well as their correlations play a fundamental role in the ... More

Stability and instability of breathers in the $U(1)$ Sasa-Satusuma and Nonlinear Schrödinger modelsJan 29 2019We consider the Sasa-Satsuma (SS) and Nonlinear Schr\"odinger (NLS) equations posed along the line, in 1+1 dimensions. Both equations are canonical integrable $U(1)$ models, with solitons, multi-solitons and breather solutions, see Yang for instance. ... More

The Akhmediev Breather is unstableOct 30 2018In this note, we give a rigorous proof that the NLS periodic Akhmediev breather is unstable. The proof follows the ideas in [17], in the sense that a suitable modification of the Stokes wave is the global attractor of the local Akhmediev dynamics for ... More

Exoplanet phase curves at large phase angles. Diagnostics for extended hazy atmospheresOct 14 2017At optical wavelengths, Titan's brightness for large Sun-Titan-observer phase angles significantly exceeds its dayside brightness. The brightening that occurs near back-illumination is due to moderately large haze particles in the moon's extended atmosphere ... More

The 1989 and 2015 outbursts of V404 Cygni: a global study of wind-related optical featuresSep 03 2018The black hole transient V404 Cygni exhibited a bright outburst in June 2015 that was intensively followed over a wide range of wavelengths. Our team obtained high time resolution optical spectroscopy (~90 s), which included a detailed coverage of the ... More

Radiation in (2+1)-dimensionsMay 15 2014In this paper we discuss the radiation equation of state $p=\rho/2$ in (2+1)-dimensions. In (3+1)-dimensions the equation of state $p=\rho/3$ may be used to describe either actual electromagnetic radiation (photons) as well as a gas of massless particles ... More

On the backwards difference filterNov 07 2007It is usual in helioseismology to remove unwanted instrumental low-frequency trends by applying high-pass filters to the time series. However, the choice of the filter is very important because it can keep the periodic signals throughout the spectrum. ... More

A survey on the inverse integrating factorMar 05 2009The relation between limit cycles of planar differential systems and the inverse integrating factor was first shown in an article of Giacomini, Llibre and Viano appeared in 1996. From that moment on, many research articles are devoted to the study of ... More

First-principles study of orthorhombic CdTiO3 perovskiteJul 23 2002Nov 07 2002In this work we perform an ab-initio study of CdTiO3 perovskite in its orthorhombic phase using FLAPW method. Our calculations help to decide between the different cristallographic structures proposed for this perovskite from X-Ray measurements. We compute ... More

Ultraviolet Spectropolarimetry as a Tool for Understanding the Diversity of Exoplanetary AtmospheresMar 14 2019Mar 15 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

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

Detection of chromatic microlensing in Q 2237+0305 AOct 09 2008Feb 03 2009We present narrowband images of the gravitational lens system Q~2237+0305 made with the Nordic Optical Telescope in eight different filters covering the wavelength interval 3510-8130 \AA. Using point-spread function photometry fitting we have derived ... More

How many active regions are necessary to predict the solar dipole moment?Jul 04 2018We test recent claims that the polar field at the end of Cycle 23 was weakened by a small number of large, abnormally oriented regions, and investigate what this means for solar cycle prediction. We isolate the contribution of individual regions from ... More

Quenched disorder forbids discontinuous transitions in nonequilibrium low-dimensional systemsFeb 06 2014Quenched disorder affects significantly the behavior of phase transitions. The Imry-Ma-Aizenman-Wehr-Berker argument prohibits first-order or discontinuous transitions and their concomitant phase coexistence in low-dimensional equilibrium systems in the ... More

Multi-mode Alfvénic Fast Particle Transport and Losses: Numerical vs. Experimental ObservationNov 11 2013In many discharges at ASDEX Upgrade fast particle losses can be observed due to Alfv\'enic gap modes, Reversed Shear Alfv\'en Eigenmodes or core-localized Beta Alfv\'en Eigenmodes. For the first time, simulations of experimental conditions in the ASDEX ... More

SHARDS: A global view of the star formation activity at z~0.84 and z~1.23Jul 28 2015Oct 21 2015In this paper, we present a comprehensive analysis of star-forming galaxies (SFGs) at intermediate redshifts (z~1). We combine the ultra-deep optical spectro-photometric data from the Survey for High-z Absorption Red and Dead Sources (SHARDS) with deep ... More

Fair Kernel LearningOct 16 2017New social and economic activities massively exploit big data and machine learning algorithms to do inference on people's lives. Applications include automatic curricula evaluation, wage determination, and risk assessment for credits and loans. Recently, ... More

Coherent Quantum Phase Slip in two-component bosonic Atomtronic CircuitsSep 15 2015Mar 18 2016Coherent Quantum Phase Slip consists in the coherent transfer of vortices in superfluids. We investigate this phenomenon in two miscible coherently coupled components of a spinor Bose gas confined in a toroidal trap. After imprinting different vortex ... More

Long-term monitoring, time delay and microlensing in the gravitational lens system Q0142-100Oct 24 2013We present twelve years of monitoring of the gravitational lens Q0142-100 from the Teide Observatory. The data, taken from 1999 to 2010, comprise 105 observing nights with the IAC80 telescope. The application of the delta2-method to the dataset leads ... More

Three-dimensional gap solitons in Bose-Einstein condensates supported by one-dimensional optical latticesOct 25 2010Nov 16 2010We study fundamental and compound gap solitons (GSs) of matter waves in one-dimensional (1D) optical lattices (OLs) in a three-dimensional (3D) weak-radial-confinement regime, which corresponds to realistic experimental conditions in Bose-Einstein condensates ... More