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An Empirical Connection between the UV Color of Early Type Galaxies and the Stellar Initial Mass FunctionOct 11 2013Using new UV magnitudes for a sample of early-type galaxies, ETGs, with published stellar mass-to-light ratios, Upsilon_*, we find a correlation between UV color and Upsilon_* that is tighter than those previously identified between Upsilon_* and either ... More

UV/H-alpha TurmoilNov 09 2010A great deal of our understanding of star formation in the local universe has been built upon an extensive foundation of H-alpha observational studies. However, recent work in the ultraviolet (UV) with GALEX has shown that star formation rates (SFRs) ... More

Strong Variable Ultraviolet Emission from Y Gem: Accretion Activity in an AGB Star with a Binary Companion?Aug 17 2011Binarity is believed to dramatically affect the history and geometry of mass loss in AGB and post-AGB stars, but observational evidence of binarity is sorely lacking. As part of a project to look for hot binary companions to cool AGB stars using the GALEX ... More

Recent stellar mass assembly of low-mass star-forming galaxies at redshifts 0.3 < z < 0.9Nov 02 2014Dec 22 2014The epoch when low-mass star forming galaxies (LMSFGs) form the bulk of their stellar mass is uncertain. While some models predict an early formation, others favor a delayed scenario until later ages of the universe. We present constraints on the star ... More

The GALEX/S4G Surface Brightness and Color Profiles Catalog - I. Surface Photometry and Color Gradients of GalaxiesOct 03 2017We present new, spatially resolved, surface photometry in FUV and NUV from images obtained by the $\textit{Galaxy Evolution Explorer}$ (GALEX), and IRAC1 (3.6 $\mu$m) photometry from the $\textit{Spitzer Survey of Stellar Structure in Galaxies}$ (S$^{4}$G) ... More

NGC 404, A Rejuvenated Lenticular Galaxy on a Merger-Induced, Blueward Excursion into the Green ValleyMar 25 2010We have discovered recent star formation in the outermost portion (1-4x R_25) of the nearby lenticular (S0) galaxy NGC 404 using GALEX UV imaging. FUV-bright sources are strongly concentrated within the galaxy's HI ring (formed by a merger event according ... More

The GALEX/S4G UV-IR color-color diagram: Catching spiral galaxies away from the Blue SequenceJan 26 2015We obtained GALEX FUV, NUV, and Spitzer/IRAC 3.6$\mu$m photometry for > 2000 galaxies, available for 90% of the S4G sample. We find a very tight "GALEX Blue Sequence (GBS)" in the (FUV-NUV) versus (NUV-[3.6]) color-color diagram which is populated by ... More

Integral Field Spectroscopy and multi-wavelength imaging of the nearby spiral galaxy NGC5668: an unusual flattening in metallicity gradientMay 22 2012We present the analysis of the full bi-dimensional optical spectral cube of the nearby spiral galaxy NGC 5668, observed with the PPAK IFU at the Calar Alto observatory 3.5m telescope. We make use of broad-band imaging to provide further constraints on ... More

Discovery of New Dwarf Galaxy near The Isolated Spiral Galaxy NGC 6503Apr 02 2015We report the discovery of a new dwarf galaxy (NGC6503-d1) during the Subaru extended ultraviolet (XUV) disk survey. It is a likely companion of the spiral galaxy NGC6503. The resolved images, in B, V, R, i, and Halpha, show an irregular appearance due ... More

The Nature of Low-Density Star FormationMar 13 2019How do stars manage to form within low-density, HI-dominated gas? Such environments provide a laboratory for studying star formation with physical conditions distinct from starbursts and the metal-rich disks of spiral galaxies where most effort has been ... More

Reply to Comment [arXiv:1708.09341] by Birse and McGovern on "Nucleon spin-averaged forward virtual Compton tensor at large $Q^2$"Nov 02 2017We reply to misleading claims made in a comment to our work by Birse and McGovern in arXiv:1708.09341.

High-resolution MEGARA IFU spectroscopy and structural analysis of a fast-rotating, disky bulge in NGC 7025Nov 26 2018Disky bulges in spiral galaxies are commonly thought to form out of disk materials (mainly) via bar driven secular processes, they are structurally and dynamically distinct from `classical bulges' built in violent merger events. We use high-resolution ... More

The S4G perspective on circumstellar dust extinction of AGB stars in M100Mar 02 2012We examine the effect of circumstellar dust extinction on the near-IR contribution of asymptotic giant branch (AGB) stars in intermediate-age clusters throughout the disk of M100. For our sample of 17 AGB-dominated clusters we extract optical-to-mid-IR ... More

Reconstructing the stellar mass distributions of galaxies using S4G IRAC 3.6 and 4.5 micron images: II. The conversion from light to massFeb 21 2014We present a new approach for estimating the 3.6 micron stellar mass-to-light ratio in terms of the [3.6]-[4.5] colors of old stellar populations. Our approach avoids several of the largest sources of uncertainty in existing techniques. By focusing on ... More

Radial variation of attenuation and star formation in the largest late-type disks observed with GALEXSep 04 2006For a sample of 43 nearby, late-type galaxies, we have investigated the radial variation of both the current star formation rate and the dust-induced UV light attenuation. To do this we have cross-correlated IRAS images and GALEX observations for each ... More

The CALIFA survey: Status ReportDec 09 2014We present here a brief summary of the status of the on-going CALIFA survey with an em- phasis on the results that have been recently published. In particular, we make a summary of the most relevant results found regarding the properties of Hii regions ... More

Learning Gaussian Graphical Models by symmetric parallel regression techniqueFeb 08 2019In this contribution we deal with the problem of learning an undirected graph which encodes the conditional dependence relationship between variables of a complex system, given a set of observations of this system. This is a very central problem of modern ... More

The NRQED lagrangian at order 1/M^4Dec 18 2012Mar 21 2013The parity and time-reversal invariant effective lagrangian for a heavy fermion interacting with an abelian gauge field, i.e., NRQED, is constructed through order $1/M^4$. The implementation of Lorentz invariance in the effective theory becomes nontrivial ... More

Numerical study on transient heat transfer under soil with plastic mulch in agriculture applications using a nonlinear finite element modelOct 08 2011In this paper is developed a simple mathematical model of transient heat transfer under soil with plastic mulch in order to determine with numerical studies the influence of different plastic mulches on the soil temperature and the evolutions of temperatures ... More

The environment of the fast rotating star Achernar - High-resolution thermal infrared imaging with VISIR in BURST modeOct 28 2007Context: The geometry of the circumstellar envelopes (CSE) surrounding Be stars is still uncertain, although it is often assumed that they are formed by a disk around the stellar equator and a hot polar wind. Achernar (Alpha Eri) is the nearest Be star, ... More

UV-IR color profiles of the outer regions of 2K nearby S$^{4}$G galaxiesJun 01 2016We present our new, spatially-resolved, photometry in FUV and NUV from images obtained by GALEX, and IRAC1 (3.6 $\mu$m) photometry obtained by the Spitzer Space Telescope. We analyzed the surface brightness profiles $\mu_{\rm{FUV}}$, $\mu_{\rm{NUV}}$, ... More

The connection between the UV colour of early type galaxies and the stellar initial mass function revisitedOct 27 2014We extend our initial study of the connection between the UV colour of galaxies and both the inferred stellar mass-to-light ratio, $\Upsilon_*$, and a mass-to-light ratio referenced to Salpeter initial mass function (IMF) models of the same age and metallicity, ... More

Leaps of modules of integrable derivations in the sense of Hasse-SchmidtJan 11 2019Let k be a commutative ring of characteristic p > 0. We prove that leaps of chain formed by modules of integrable derivations in the sense of Hasse-Schmidt of a k-algebra only occur at powers of p.

Integrable derivations in the sense of Hasse-Schmidt for some binomial plane curveJul 27 2018We describe the module of integrable derivations in the sense of Hasse-Schmidt of the quotient of the polinomial ring in two variables over an ideal generated by the equation x^n-y^q.

Hot Stars Mass-loss studied with Spectro-Polarimetric INterferometry (SPIN)Jul 23 2003We present a prospective work undertaken on Spectro-Polarimetric INterferometry (SPIN). Our theoretical studies suggest that SPIN is a powerful tool for studying the mass loss from early type stars. Based on Monte Carlo simulations, we computed the expected ... More

Nonlocal single particle correlations and EPR state in the double-slit experimentFeb 21 2017Quantum correlations of observables for two particle states have demonstrated the nonlocal character of the quantum mechanics. However nonlocality can be exhibited even for noncommuting observables of a single particle system. In this paper we show nonlocality ... More

The Calibration of Monochromatic Far-Infrared Star Formation Rate IndicatorsMar 04 2010(Abridged) Spitzer data at 24, 70, and 160 micron and ground-based H-alpha images are analyzed for a sample of 189 nearby star-forming and starburst galaxies to investigate whether reliable star formation rate (SFR) indicators can be defined using the ... More

Pipe3D, a pipeline to analyse integral field spectroscopy data: II. Analysis sequence and CALIFA dataproductsFeb 03 2016We present Pipe3D, an analysis pipeline based on the FIT3D fitting tool, devel- oped to explore the properties of the stellar populations and ionized gas of Integral Field Spectroscopy data. Pipe3D was created to provide with coherent, simple to distribute, ... More

Integral field spectroscopy of a sample of nearby galaxies: II. Properties of the H ii regionsAug 06 2012In this work we analyze the spectroscopic properties of a large number of H ii regions, \sim2600, located in 38 galaxies. The sample of galaxies has been assembled from the face-on spirals in the PINGS survey and a sample described in M\'armol-Queralt\'o ... More

The Baryonic Tully-Fisher Relationship for S$^4$G Galaxies and the "Condensed" Baryon Fraction of GalaxiesFeb 25 2014Feb 26 2014We combine data from the Spitzer Survey for Stellar Structure in Galaxies (S$^4$G), a recently calibrated empirical stellar mass estimator from Eskew et al., and an extensive database of HI spectral line profiles to examine the baryonic Tully-Fisher (BTF) ... More

Spontaneous and Stimulated Star Formation in GalaxiesJan 09 2008We present recent results from several on-going studies: The first addresses the question of gas-density thresholds for star formation, as probed by the outer disks of normal nearby galaxies. The second concerns the observational evidence for the existence ... More

Contribution of the disks to the SFR in the local Universe using Integral Field Spectroscopy from CALIFAMay 21 2014The Calar Alto Legacy Integral Field Area survey (CALIFA survey) is providing Integral Field Spectroscopy (IFS) data in the entire optical window for a diameter-limited sample of 600 objects in the Local Universe (0.005$<$z$<$0.03). One of the main goals ... More

A comparative study of the spatial distribution of ultraviolet and far-infrared fluxes from M 101Nov 12 2004The total ultraviolet (UV) flux (from 1412 to 2718 AA) of M 101 is compared on a pixel-to-pixel basis with the total far-infrared (FIR) flux (from 60 to 170 micron), using the maps of the galaxy taken by GALEX in the near-UV and far-UV and by ISOPHOT ... More

Recent Star Formation in the Extreme Outer Disk of M83Nov 11 2004Ultraviolet imaging with the Galaxy Evolution Explorer (GALEX) has revealed an extensive sample of UV-bright stellar complexes in the extreme outer disk of M83, extending to about four times the radius where the majority of HII regions are detected (R_HII ... More

The impact of bars on disk breaks as probed by S4G imagingApr 22 2013We have analyzed the radial distribution of old stars in a sample of 218 nearby face-on disks, using deep 3.6um images from the Spitzer Survey of Stellar Structure in Galaxies (S4G). In particular, we have studied the structural properties of those disks ... More

Star formation in the nearby universe: the ultraviolet and infrared points of viewJan 11 2006This work presents the main ultraviolet (UV) and far-infrared (FIR) properties of two samples of nearby galaxies selected from the GALEX ($\lambda = 2315$\AA, hereafter NUV) and IRAS ($\lambda = 60\mu$m) surveys respectively. They are built in order to ... More

Positivity of the height jump divisorJan 02 2017Mar 22 2018We study the degeneration of semipositive smooth hermitian line bundles on open complex manifolds, assuming that the metric extends well away from a codimension two analytic subset of the boundary. Using terminology introduced by R. Hain, we show that ... More

Quantum walk on a cylinderJul 27 2016Sep 09 2016We consider the 2D alternate quantum walk on a cylinder. We concentrate on the study of the motion along the open dimension, in the spirit of looking at the closed coordinate as a small or "hidden" extra dimension. If one starts from localized initial ... More

Understanding and controlling N-dimensional quantum walks via dispersion relations. Application to the 2D and 3D Grover walks: Diabolical points and moreDec 17 2012May 13 2013The discrete quantum walk in N dimensions is analyzed from the perspective of its dispersion relations. This allows understanding known properties, as well as designing new ones when spatially extended initial conditions are considered. This is done by ... More

First Experiences Optimizing Smith-Waterman on Intel's Knights Landing ProcessorFeb 23 2017The well-known Smith-Waterman (SW) algorithm is the most commonly used method for local sequence alignments. However, SW is very computationally demanding for large protein databases. There exist several implementations that take advantage of computing ... More

New Criteria of Generic Hyperbolicity based on Periodic PointsJun 12 2009Jun 12 2012We prove a criteria for uniform hyperbolicity based on the periodic points of the transformation. More precisely, if a mild (non uniform) hyperbolicity condition holds for the periodic points of any diffeomorphism in a residual subset of a $C^1$-open ... More

Configuration dependent demagnetizing field in assemblies of interacting magnetic particlesFeb 06 2013A mean field model is presented for the configuration dependent effective demagnetizing and anisotropy fields in assemblies of exchange decoupled magnetic particles of arbitrary shape which are expressed in terms of the demagnetizing factors of the particles ... More

A Natural Concept of Image in the Physics of fr. Alonso de la VeracruzJan 01 2001Alonso de la Veracruz conducted a physical study of image, regarding the activities of Soul in which image is produced, as organic operations. This research was particularly important since, at that time, image was systematically used to propagate the ... More

A proof that all Seifert 3-manifold groups and all virtual surface groups are conjugacy separableMay 26 2005We prove that the fundamental group of any Seifert 3-manifold is conjugacy separable. That is, conjugates may be distinguished in finite quotients or, equivalently, conjugacy classes are closed in the pro-finite topology.

Interpretation of the observations made in 1883 in Zacatecas (Mexico): A fragmented Comet that nearly hits the EarthOct 12 2011In 1883, on the 12th and 13th of August, Mexican astronomer Jose A. y Bonilla observed several objects passing in front of the solar disk. In 1886 in the L'Astronomie magazine, he reported his observations without providing a hypothesis explaining the ... More

Entanglement of self interacting scalar fields in an expanding spacetimeJul 11 2016We evaluate self-interaction effects on the quantum correlations of field modes of opposite momenta for scalar $\lambda \phi^4$ theory in a two-dimensional asymptotically flat Robertson-Walker spacetime. Such correlations are encoded both in the von-Neumann ... More

Percolation of New Product Critical Market PenetrationApr 04 2004A simulation of new product market penetration in a social environment is performed, using a spintronic model, where each element of a 3D network interacts with its first neighbors. Agents are assumed to be rational, with a perfect market foresight. Unitary ... More

Anomalous CMB north-south asymmetrySep 05 2008Several accurate analyses have revealed a statistically significant North-South ecliptic asymmetry in the large-angle correlations strength of the Cosmic Microwave Background (CMB) radiation temperature field data from the Wilkinson Microwave Anisotropy ... More

Predicting online user behaviour using deep learning algorithmsNov 19 2015May 26 2016We propose a robust classifier to predict buying intentions based on user behaviour within a large e-commerce website. In this work we compare traditional machine learning techniques with the most advanced deep learning approaches. We show that both Deep ... More

A new macroscopic model derived from the Boltzmann equation and the discontinuous Galerkin method for solving kinetic equationsSep 05 2011We propose a new macroscopic model derived from the classical nonlinear Boltzmann equation. A set of partial differential equations is obtained easily. The unknowns depend on the time and space coordinates, and are related to the distribution function, ... More

A semi-discrete Boltzmann equation based on a finite volume schemeNov 28 2017In this work we consider the classical non-linear Boltzmann equation, where the unknown is the distribution function $f$, which depends on the time $t$, the vector $\mathbf{x}$ (the position of a molecule) and its velocity $\mathbf{\xi}$. From the Boltzmann ... More

$σ$-PBW Extensions of Skew $Π$-Armendariz RingsMay 29 2018In this paper we present the notion of skew $\Pi$-Armendariz for the non-commutative rings known as $\sigma$-PBW extensions. This concept generalizes several definitions of Armendariz rings presented in the literature for these extensions, and in particular, ... More

When $π(n)$ does not divide $n$Sep 08 2014Jan 26 2015Let $\pi(n)$ denote the prime-counting function and let $$f(n)=\left|\left\lfloor\log n-\lfloor\log n\rfloor-0.1\right\rfloor\right|\left\lfloor\frac{\left\lfloor n/\lfloor\log n-1\rfloor\right\rfloor\lfloor\log n-1\rfloor}{n}\right\rfloor\text{.}$$ In ... More

Two statements that are equivalent to a conjecture related to the distribution of prime numbersJun 03 2014Jun 19 2014Let $n\in\mathbb{Z}^+$. In [8] we ask the question whether any sequence of $n$ consecutive integers greater than $n^2$ and smaller than $(n+1)^2$ contains at least one prime number, and we show that this is actually the case for every $n\leq 1,193,806,023$. ... More

On the Minimum Consistent Subset ProblemOct 22 2018Nov 26 2018Let $P$ be a set of $n$ colored points in the plane. Introduced by Hart (1968), a consistent subset of $P$, is a set $S\subseteq P$ such that for every point $p$ in $P\setminus S$, the closest point of $p$ in $S$ has the same color as $p$. The consistent ... More

Engineering Fragile Topology in Photonic Crystals: Topological Quantum Chemistry of LightMar 06 2019In this Letter, we apply the recently developed theory of "Topological quantum chemistry" to the study of band structures in photonic crystals. We focus on a family of crystals formed by elliptical rods in a triangular lattice. We show that the symmetry ... More

The galactic unclassified B[e] star HD 50138. I. A possible new shell phaseNov 13 2009The observed spectral variation of HD 50138 has led different authors to classify it in a very wide range of spectral types and luminosity classes (from B5 to A0 and III to Ia) and at different evolutionary stages as either HAeBe star or classical Be. ... More

A Study of Heating and Cooling of the ISM in NGC 1097 with Herschel-PACS and Spitzer-IRSApr 02 2012NGC 1097 is a nearby Seyfert 1 galaxy with a bright circumnuclear starburst ring, a strong large-scale bar and an active nucleus. We present a detailed study of the spatial variation of the far infrared (FIR) [CII]158um and [OI]63um lines and mid-infrared ... More

Mapping far-IR emission from the central kiloparsec of NGC 1097May 11 2010Using photometry of NGC 1097 from the Herschel PACS (Photodetector Array Camera and Spectrometer) instrument, we study the resolved properties of thermal dust continuum emission from a circumnuclear starburst ring with a radius ~ 900 pc. These observations ... More

On the Optimization of Broad-Band Photometry for Galaxy Evolution StudiesJan 02 2002We have derived the uncertainties to be expected in the derivation of galaxy physical properties (star formation history, age, metallicity, reddening) when comparing broad-band photometry to the predictions of evolutionary synthesis models. We have obtained ... More

Palomar/Las Campanas Imaging Atlas of Blue Compact Dwarf Galaxies: II. Surface Photometry and the Properties of the Underlying Stellar PopulationOct 22 2004We present the results from an analysis of surface photometry of B, R, and Halpha images of a total of 114 nearby galaxies drawn from the Palomar/Las Campanas Imaging Atlas of Blue Compact Dwarf galaxies. Surface brightness and color profiles for the ... More

The Universal Initial Mass Function In The XUV Disk of M83Feb 09 2012We report deep Subaru Halpha observations of the XUV disk of M83. These new observations enable the first complete census of very young stellar clusters over the entire XUV disk. Combining Subaru and GALEX data with a stellar population synthesis model, ... More

The stellar mass assembly of galaxies from z=0 to z=4. Analysis of a sample selected in the rest-frame near-infrared with SpitzerSep 10 2007Mar 25 2008Using a sample of ~28,000 sources selected at 3.6-4.5 microns with Spitzer observations of the HDF-N, the CDF-S, and the Lockman Hole (surveyed area: ~664 arcmin^2), we study the evolution of the stellar mass content of the Universe at 0<z<4. We calculate ... More

IC 3418: Star Formation in a Turbulent WakeJun 30 2010Galaxy Evolution Explorer observations of IC 3418, a low surface brightness galaxy in the Virgo Cluster, revealed a striking 17 kpc UV tail of bright knots and diffuse emission. H alpha imaging confirms that star formation is ongoing in the tail. IC 3418 ... More

The Charge Radius of the ProtonSep 26 2011Recently, the charge radius of the proton was extracted for the first time from muonic hydrogen. The value obtained is five standard deviations away from similar measurements of regular hydrogen. This talk discusses work done in collaboration with Richard ... More

Direct CP Asymmetry in B->X_{s,d}+gamma DecaysJun 22 2011The CP asymmetry in inclusive B->X_{s,d}+gamma decays is an important probe of new physics. The theoretical prediction was thought to be of a perturbative origin, and in the standard model, to be about 0.5 percent. In a recent work with M. Benzke, S.J. ... More

SU(3) - Flavor Symmetry in $B \to VP$ DecaysJun 28 2002In the framework of SU(3) symmetry, we present a general analysis of $B$ meson decays into two lighter uncharmed mesons (both pairs of pseudoscalar mesons and pairs of vector and pseudoscalar mesons). From the analysis we find constraints on $\gamma$ ... More

An Introduction to NRQEDMar 24 2015Aug 17 2015We present a pedagogical introduction to NRQED (non-relativistic quantum electrodynamics). NRQED is an effective field theory that describes the interaction of non-relativistic, possibly composite, spin-half particle with the electromagnetic field. We ... More

Precision Determination of $|V_{ub}|$Dec 07 2006Apr 30 2007The last two years have seen an impressive improvement in the determination of $|V_{ub}|$, especially from inclusive decays. The error on $|V_{ub}|$ measured with inclusive decays was reduced from 18% (PDG 2004) to 8% (PDG 2006). This progress is a result ... More

Theory of Inclusive Radiative B DecaysNov 22 2010This talk discusses recent developments in the theory of inclusive radiative B decays, focusing mainly on non-perturbative aspects of B->Xs gamma.

An Effective Field Theory Look at Deep Inelastic ScatteringJun 16 2010This talk discusses the effective field theory view of deep inelastic scattering. In such an approach, the standard factorization formula of a hard coefficient multiplied by a parton distribution function arises from matching of QCD onto an effective ... More

Theory of Inclusive Radiative B Decays: 2012 UpdateDec 19 2012This talk discusses recent developments in the theory of inclusive radiative B decays, focusing mainly on non-perturbative aspects of the CP asymmetry in B->Xs gamma.

From A to Z': Combining Anomaly and Z' Mediation of Supersymmetry BreakingOct 13 2009Combining anomaly with Z' mediation allows us to solve the tachyonic slepton problem of the former and avoid fine tuning in the latter. We describe how the two mechanisms can be combined, and some of the phenomenology of such a joint scenario.

Subleading Jet Functions in Inclusive B DecaysMar 19 2009Jul 14 2009The contribution of subleading jet functions to inclusive decay distributions of $B$ mesons are derived from a systematic two-step matching of QCD current correlators onto soft collinear and heavy quark effective theory. Focusing on the tree level matching ... More

Charmless inclusive B decays and the extraction of V(ub)Jul 19 2006This work discusses charmless inclusive B decays and their application to the extraction of $|V_{ub}|$. Starting from first principles we relate the differential decay rate to the hadronic tensor in terms of optimal choice of kinematical variables. We ... More

The non-self-adjointness of the radial momentum operator in n dimensionsSep 11 2000Apr 24 2002The non self-adjointness of the radial momentum operator has been noted before by several authors, but the various proofs are incorrect. We give a rigorous proof that the $n$-dimensional radial momentum operator is not self- adjoint and has no self-adjoint ... More

On the connection between the radial momentum operator and the Hamiltonian in n dimensionsSep 11 2000Jun 19 2001The radial momentum operator in quantum mechanics is usually obtained through canonical quantization of the (symmetrical form of the) classical radial momentum. We show that the well known connection between the Hamiltonian of a free particle and the ... More

The horofunction boundary of finite-dimensional $\ell_p$ spacesSep 11 2017Dec 28 2018We give a complete description of the horofunction boundary of finite-dimensional $\ell_p$ spaces for $1\leq p\leq \infty$. We also study the variation norm on $\mathbb{R}^{\mathcal{N}}$, $\mathcal{N}=\{1,...,N\}$, and the corresponding horofunction boundary. ... More

Koszulity for skew PBW extensions over fieldsNov 11 2016Koszul and homogeneous Koszul algebras were defined by Priddy in \cite{Priddy1970}. There exist some relations between these algebras and the skew PBW extensions introduced in \cite{LezamaGallego}. In this paper we give conditions to guarantee that skew ... More

Global finite element matrix construction based on a CPU-GPU implementationJan 20 2015The finite element method (FEM) has several computational steps to numerically solve a particular problem, to which many efforts have been directed to accelerate the solution stage of the linear system of equations. However, the finite element matrix ... More

Equilibrium states for non-uniformly expanding maps: decay of correlations and strong stabilityMay 24 2012Jul 19 2012We study the rate of decay of correlations for equilibrium states associated to a robust class of non-uniformly expanding maps where no Markov assumption is required. We show that the Ruelle-Perron-Frobenius operator acting on the space of Holder continuous ... More

Displacements of automorphisms of free groups II: Connectivity of level sets and decision problemsJul 08 2018This is the second of two papers in which we investigate the properties of displacement functions of automorphisms of free groups (more generally, free products) on the Culler-Vogtmann Outer space $CV_n$ and its simplicial bordification. We develop a ... More

Linear response, and consequences for differentiability of statistical quantities and Multifractal AnalysisNov 16 2017Nov 28 2017In this article we initially fix ourselves to smooth expanding dynamical systems. We prove the differentiability of the topological pressure, equilibrium states and their densities with respect to smooth expanding dynamical systems and any smooth potential. ... More

New Upper Bounds on the Distance Domination Numbers of GridsOct 15 2014In his 1992 Ph.D. thesis Chang identified an efficient way to dominate $m \times n$ grid graphs and conjectured that his construction gives the most efficient dominating sets for relatively large grids. In 2011 Gon\c{c}alves, Pinlou, Rao, and Thomass\'e ... More

On the metric compactification of infinite-dimensional $\ell_{p}$ spacesFeb 13 2018Dec 28 2018The notion of metric compactification was introduced by Gromov and later rediscovered by Rieffel; and has been mainly studied on proper geodesic metric spaces. We present here a generalization of the metric compactification that can be applied to infinite-dimensional ... More

Enveloping Algebra and Skew Calabi-Yau algebras over Skew Poincaré-Birkhoff-Witt ExtensionsApr 18 2018In this paper we show that the tensor product of skew PBW extensions is a skew PBW ex- tension. We also characterize the enveloping algebra of a skew PBW extension. Finally, we establish sufficient conditions to guarantee the property of being skew Calabi-Yau ... More

Engineering of quantum dot photon sources via electro-elastic fieldsMar 01 2015The possibility to generate and manipulate non-classical light using the tools of mature semiconductor technology carries great promise for the implementation of quantum communication science. This is indeed one of the main driving forces behind ongoing ... More

Primitive recursive functions versus partial recursive functions: comparing the degree of undecidabilityJul 06 2016Consider a decision problem whose instance is a function. Its degree of undecidability, measured by the corresponding class of the arithmetic (or Kleene-Mostowski) hierarchy hierarchy, may depend on whether the instance is a partial recursive or a primitive ... More

The Tracy-Widom distribution is not infinitely divisibleJan 12 2016The classical infinite divisibility of distributions related to eigenvalues of some random matrix ensembles is investigated. It is proved that the $\beta$-Tracy-Widom distribution, which is the limiting distribution of the largest eigenvalue of a $\beta$-Hermite ... More

Transitivity and rotation sets with nonempty interior for homeomorphisms of the 2-TorusDec 04 2010We show that, if $f$ is a homeomorphism of the 2--torus isotopic to the identity, and its lift $\widetilde f$ is transitive, or even if it is transitive outside of the lift of the elliptic islands, then $(0,0)$ is in the interior of the rotation set of ... More

A Finite Difference Ghost-Cell Multigrid Approach for Poisson Equation with Mixed Boundary Conditions in Arbitrary DomainNov 03 2011In this paper we present a multigrid approach to solve the Poisson equation in arbitrary domain (identified by a level set function) and mixed boundary conditions. The discretization is based on finite difference scheme and ghost-cell method. This multigrid ... More

Some homological properties of skew PBW extensionsOct 24 2013We prove that if R is a left Noetherian and left regular ring then the same is true for any bijective skew PBW extension A of R. From this we get Serre's Theorem for such extensions. We show that skew PBW extensions and its localizations include a wide ... More

The metric compactification of $L_{p}$ represented by random measuresMar 06 2019We present a complete characterization of the metric compactification of $L_{p}$ for all $1 \leq p < \infty$. Each element of the metric compactification of $L_{p}$ is represented by a random measure on a certain Polish space. By way of illustration, ... More

Interbreeding conditions for explaining Neandertal DNA in living humans: the nonneutral caseMay 30 2011We consider here an extension of a previous work by Neves and Serva, still unpublished, which estimates the amount of interbreeding between anatomically modern Africans and Neandertals necessary for explaining the experimental fact that 1 to 4% of the ... More

Statistical properties of the maximal entropy measure for partially hyperbolic attractorsOct 05 2016We show the existence and uniqueness of the maximal entropy probability measure for partially hyperbolic diffeomorphisms which are semi-conjugate to nonuniformly expanding maps. Using the theory of projective metric on cones we then prove exponential ... More

A generalized Koszul property for skew PBW extensionsApr 18 2018Let R be a commutative algebra. In this paper we show that constant skew PBW extensions of a generalized Koszul algebra R are also generalized Koszul. Let A be a semi-commutative skew PBW extension of R such that A is R-augmented. We show also that if ... More

Skew PBW extensions over weak symmetric and $(Σ,Δ)$-weak symmetric ringsJul 13 2018In this paper we study skew Poincar\'e-Birkhoff-Witt extensions over weak symmetric and $(\Sigma,\Delta)$-weak symmetry rings. Since these extensions generalize Ore extensions of injective type and another noncommutative rings of polynomial type, we unify ... More

Skew Poincaré-Birkhoff-Witt extensions over weak $Σ$-rigid ringsMay 29 2018In this paper we introduce the notion of weak $\Sigma$-rigid ring which extends $\alpha$-rigid rings and $\Sigma$-rigid rings defined for Ore extensions and skew PBW extensions, respectively. We also present the notion of weak $\Sigma$-skew Armendariz ... More

Formation of Double Neutron Star systems as implied by observationsOct 11 2015Jan 10 2016Double Neutron Stars (DNS) have to survive two supernovae and still remain bound. This sets strong limits on the nature of the second collapse in these systems. We consider the masses and orbital parameters of the DNS population and constrain the two ... More

Endurance of Quantum Coherence in Born-Markov Open Quantum SystemsSep 13 2017Quantum coherence, the physical property underlying fundamental phenomena such as multi-particle interference and entanglement, has emerged as a valuable resource upon which exotic modern technologies are founded. In general, the most prominent adversary ... More