Results for "F. Pérez"

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The Dilating Method for Cayley digraphs on finite Abelian groupsNov 16 2016Mar 18 2017A geometric method for obtaining an infinite family of Cayley digraphs of constant density on finite Abelian groups is presented. The method works for any given degree and it is based on consecutive dilates of a minimum distance diagram associated with ... More
Abelian Cayley digraphs with asymptotically large order for any given degreeFeb 10 2015Abelian Cayley digraphs can be constructed by using a generalization to $Z^n$ of the concept of congruence in $Z$. Here we use this approach to present a family of such digraphs, which, for every fixed value of the degree, have asymptotically large number ... More
Dissipative particle dynamics simulations of weak polyelectrolyte adsorption on charged and neutral surfaces as a function of the degree of ionizationSep 28 2012The influence of the chain degree of ionization on the adsorption of weak polyelectrolytes on neutral and on oppositely and likely charged surfaces is investigated for the first time, by means of Monte Carlo simulations with the mesoscopic interaction ... More
On Gagliardo-Nirenberg type inequalitiesNov 06 2012We present a Gagliardo-Nirenberg inequality which bounds Lorentz norms of the function by Sobolev norms and homogeneous Besov quasinorms with negative smoothness. We prove also other versions involving Besov or Triebel-Lizorkin quasinorms. These inequalities ... More
Modeling the chemical impact and the optical emissions produced by lightning-induced electromagnetic fields in the upper atmosphere: the case of halos and elves triggered by different lightning dischargesJan 22 2019Halos and elves are Transient Luminous Events (TLEs) produced in the lower ionosphere as a consequence of lightning-driven electromagnetic fields. These events can influence the upper-atmospheric chemistry and produce optical emissions. We have developed ... More
Mesospheric optical signatures of possible lightning on VenusJan 20 2018A self-consistent two-dimensional model is proposed to account for the transient mesospheric nighttime optical emissions associated to possible intra-cloud (IC) lightning occurring in the Venusian troposphere. The model calculates the mesospheric (between ... More
Hypoxic Cell Waves around Necrotic Cores in Glioblastoma: A Biomathematical Model and its Therapeutic ImplicationsApr 17 2012Glioblastoma is a rapidly evolving high-grade astrocytoma that is distinguished pathologically from lower grade gliomas by the presence of necrosis and microvascular hiperplasia. Necrotic areas are typically surrounded by hypercellular regions known as ... More
Besov-weak-Herz spaces and global solutions for Navier-Stokes equationsApr 24 2017We consider the incompressible Navier-stokes equations (NS) in $\mathbb{R}^{n}$ for $n\geq2$. Global well-posedness is proved in critical Besov-weak-Herz spaces (BWH-spaces) that consist in Besov spaces based on weak-Herz spaces. These spaces are larger ... More
High-order harmonic generation driven by chirped laser pulses induced by linear and non linear phenomenaMar 11 2016We present a theoretical study of high-order harmonic generation (HHG) driven by ultrashort optical pulses with different kind of chirps. The goal of the present work is perform a detailed study to clarify the relevant parameters in the chirped pulses ... More
Asymptotics for Laguerre-Sobolev type ortogonal polynomials modified within their oscillatory regimeJun 27 2013Mar 12 2014In this paper we consider sequences of polynomials orthogonal with respect to certain discrete Laguerre-Sobolev inner product, with two perturbations (involving derivatives) located inside the oscillatory region for the classical Laguerre polynomials. ... More
Homology and Cohomology of Finite SpacesSep 21 2018We provide base change theorems, projection formulae and Verdier duality for both cohomology and homology in the context of finite topological spaces
High-order harmonic generation driven by metal nanotip photoemission: theory and simulationsSep 02 2013We present theoretical predictions of high-order harmonic generation (HHG) resulting from the interaction of short femtosecond laser pulses with metal nanotips. It has been demonstrated that high energy electrons can be generated using nanotips as sources; ... More
Identification of epileptic regions from electroencephalographic data: Feigenbaum graphsFeb 07 2019Diagnosing epilepsy is a problem of crucial importance. So analysing EEG data is of much importance to help this diagnosis. Assembling the Feigenbaum graphs for EEG signals. And calculating their average clustering, average degree, and average shortest ... More
Asteroseismology of delta Scuti stars in open clusters: PraesepeJul 05 2007The present paper provides a general overview of the asteroseismic potential of delta Scuti stars in clusters, in particular focusing on convection diagnostics. We give a summarise of the last results obtained by the authors for the Praesepe cluster of ... More
A class of orthogonal functions given by a three term recurrence formulaMay 14 2013The main goal in this manuscript is to present a class of functions satisfying a certain orthogonality property for which there also exists a three term recurrence formula. This class of functions, which can be considered as an extension to the class ... More
A fractional Helly theorem for boxesOct 02 2014Let $\mathcal{F}$ be a family of $n$ axis-parallel boxes in $\mathbb{R}^d$ and $\alpha\in (1-1/d,1]$ a real number. There exists a real number $\beta(\alpha )>0$ such that if there are $\alpha {n\choose 2}$ intersecting pairs in $\mathcal{F}$, then $\mathcal{F}$ ... More
Heat conduction in systems with Kolmogorov-Arnold-Moser phase space structureSep 28 2012We study heat conduction in a billiard channel formed by two sinusoidal walls and the diffusion of particles in the corresponding channel of infinite length; the latter system has an infinite horizon, i.e., a particle can travel an arbitrary distance ... More
Sobolev orthogonal polynomials on product domainsJun 03 2014Orthogonal polynomials on the product domain $[a_1,b_1] \times [a_2,b_2]$ with respect to the inner product $$ \langle f,g \rangle_S = \int_{a_1}^{b_1} \int_{a_2}^{b_2} \nabla f(x,y)\cdot \nabla g(x,y)\, w_1(x)w_2(y) \,dx\, dy + \lambda f(c_1,c_2)g(c_1,c_2) ... More
Constraints on Enhanced Dark Matter Annihilation from IceCube ResultsJul 12 2011May 25 2012Excesses on positron and electron fluxes measured by ATIC, and the PAMELA and Fermi--LAT telescopes can be explained by dark matter annihilation in our Galaxy. However, this requires large boosts on the dark matter annihilation rate. There are many possible ... More
Gerber-Shiu functionals at Parisian ruin for Lévy insurance risk processesJul 25 2014Mar 12 2015Inspired by works of Landriault et al. \cite{LRZ-0, LRZ}, we study discounted penalties at ruin for surplus dynamics driven by a spectrally negative L\'evy process with Parisian implementation delays. To be specific, we study the so-called Gerber-Shiu ... More
Rare Decays with Missing Energy at SuperBDec 06 2010The study of rare B-decays at SuperB provides unique opportunities to understand the Standard Model and to constrain new physics. It is discussed the new physics potential of the B -> K\nu\nu and B -> K^*\nu\nu system from the proposed SuperB experiment ... More
The conditioning of block Kronecker $\ell$-ifications of matrix polynomialsAug 03 2018Aug 08 2018A strong $\ell$-ification of a matrix polynomial $P(\lambda)=\sum A_i\lambda^i$ of degree $d$ is a matrix polynomial $\mathcal{L}(\lambda)$ of degree $\ell$ having the same finite and infinite elementary divisors, and the same numbers of left and right ... More
Asymptotic properties of the Dirac quantum cellular automatonApr 28 2015Jan 25 2016We show that the Dirac quantum cellular automaton [Ann. Phys. 354 (2015) 244] shares many properties in common with the discrete-time quantum walk. These similarities can be exploited to study the automaton as a unitary process that takes place at regular ... More
Effect of mixed pinning landscapes produced by 6 MeV Oxygen irradiation on the resulting critical current densities J$_c$ in 1.3 $μ$m thick GdBa$_2$Cu$_3$O$_{7-d}$ coated conductors grown by co-evaporationJun 13 2017Aug 17 2017We report the influence of crystalline defects introduced by 6 MeV $^{16}$O$^{3+}$ irradiation on the critical current densities J$_c$ and flux creep rates in 1.3 $\mu$m thick GdBa$_2$Cu$_3$O$_{7-d}$ coated conductor produced by co-evaporation. Pristine ... More
Heat kernel methods for Lifshitz theoriesMar 14 2017Jun 08 2017We study the one-loop covariant effective action of Lifshitz theories using the heat kernel technique. The characteristic feature of Lifshitz theories is an anisotropic scaling between space and time. This is enforced by the existence of a preferred foliation ... More
On the Cooperation of the Constraint Domains H, R and FD in CFLPApr 14 2009This paper presents a computational model for the cooperation of constraint domains and an implementation for a particular case of practical importance. The computational model supports declarative programming with lazy and possibly higher-order functions, ... More
Local compactness in right bounded asymmetric normed spacesFeb 13 2017We characterize the finite dimensional asymmetric normed spaces which are right bounded and the relation of this property with the natural compactness properties of the unit ball, as compactness and strong compactness. In contrast with some results found ... More
Extreme points and geometric aspects of compact convex sets in asymmetric normed spacesApr 02 2014Inspired in the theorem of Krein-Milamn, we investigate the existence of extreme points in compact convex subsets of asymmetric normed spaces. We focus our attention in the finite dimensional case, giving a geometric description of all compact convex ... More
Detection of a multi-shell planetary nebula around the hot subdwarf O-type star 2MASS J19310888+4324577Jan 30 2013(Abridged) The origin of hot subdwarf O-type stars (sdOs) remains unclear since their discovery in 1947. Among others, a post-Asymptotic Giant Branch (post-AGB) origin is possible for a fraction of sdOs. We are involved in a comprehensive ongoing study ... More
Laser emission with excitonic gain in a ZnO planar microcavityJun 01 2011The lasing operation of a ZnO planar microcavity under optical pumping is demonstrated from T=80 K to 300 K. At the laser threshold, the cavity switches from the strong coupling to the weak coupling regime. A gain-related transition, which appears while ... More
Ergodic Approach for Nonconvex Robust Optimization ProblemsFeb 27 2019In this work we show the consistency of an approach for solving robust optimization problems using sequences of sub-problems generated by erogodic measure preserving transformations. The main result of this paper is that the minimizers and the optimal ... More
Formulae for the Conjugate and the Subdifferential of the Supremum FunctionDec 26 2017May 24 2018The aim of this work is to provide formulae for the subdifferential and the conjungate function of the supremun function over an arbitrary family of functions. The work is principally motivated by the case when data functions are lower semicontinuous ... More
Smoothed Combined Field Integral Equations for Exterior Helmholtz ProblemsJan 13 2017This paper presents smoothed combined field integral equations for the solution of Dirichlet and Neumann exterior Helmholtz problems. The integral equations introduced in this paper are smooth in the sense that they only involve continuously differentiable ... More
Optimal comparison of $P$-norms of Dirichlet PolynomialsMar 07 2016Let $1 \leq p < q < \infty$. We show that \[ \sup{\frac{\left\| D\right\|_{\mathcal{H}_{q}}}{\left\| D\right\|_{\mathcal{H}_{p}}}} = \exp{\left( \frac{\log{x}}{\log{\log{x}}} \left(\log{\sqrt{\frac{q}{p}}} + \left(\frac{\log{\log{\log{x}}}}{\log{\log{x}}}\right)\right) ... More
The Fixed Initial Credit Problem for Partial-Observation Energy Games is Ack-completeDec 14 2015Nov 16 2016In this paper we study two-player games with asymmetric partial observation and an energy objective. Such games are played on a weighted automaton by Eve, choosing actions, and Adam, choosing a transition labelled with the given action. Eve attempts to ... More
The Frobenius exponent of Cartier subalgebrasNov 08 2018Let $R$ be a standard graded finitely generated algebra over an $F$-finite field of prime characteristic, localized at its maximal homogeneous ideal. In this note, we prove that that Frobenius complexity of $R$ is finite. Moreover, we extend this result ... More
Hardy spaces of vector-valued Dirichlet seriesMar 07 2016Given a Banach space $X$ and $1 \leq p \leq \infty$, it is well known that the two Hardy spaces $H_p(\mathbb{T},X)$ ($\mathbb{T}$ the torus) and $H_p(\mathbb{D},X)$ ($\mathbb{D}$ the disk) have to be distinguished carefully. This motivates us to define ... More
Surgery in colored tensor modelsJul 31 2016Jun 19 2017Rooted in group field theory and matrix models, random tensor models are a recent background-invariant approach to quantum gravity in arbitrary dimensions. Colored tensor models (CTM) generate random triangulated orientable (pseudo)-manifolds. We analyze, ... More
Subdifferential formulae for the supremum of an arbitrary family of functionsJan 02 2018Dec 03 2018This work provides calculus for the Fr\'echet and limiting subdifferential of the pointwise supremum given by an arbitrary family of lower semicontinuous functions. We start our study showing fuzzy results about the Fr\'echet subdifferential of the supremum ... More
STEAM-MakerspaceSep 22 2018Implementation of a STEAM Makerspace to dynamize the teaching and learning processes of mathematics (with emphasis on geometry) of second-year students in the upper secondary level.
A Flexible Convolutional Solver with Application to Photorealistic Style TransferJun 13 2018We propose a new flexible deep convolutional neural network (convnet) to perform fast visual style transfer. In contrast to existing convnets that address the same task, our architecture derives directly from the structure of the gradient descent originally ... More
Degenerate Poincaré-Sobolev inequalitiesMay 25 2018Mar 02 2019We study weighted Poincar\'e and Poincar\'e-Sobolev type inequalities with an explicit analysis on the dependence on the $A_p$ constants of the involved weights. We obtain inequalities of the form $$ \left (\frac{1}{w(Q)}\int_Q|f-f_Q|^{q}w\right )^\frac{1}{q}\le ... More
Real valued functions and metric spaces quasi-isometric to treesMar 30 2011We prove that if X is a complete geodesic metric space with uniformly generated first homology group and $f: X\to R$ is metrically proper on the connected components and bornologous, then X is quasi-isometric to a tree. Using this and adapting the definition ... More
Zig-zag chains and metric equivalences between ultrametric spacesSep 01 2009We study the classification of ultrametric spaces based on their small scale geometry (uniform homeomorphism), large scale geometry (coarse equivalence) and both (all scale uniform equivalences). We prove that these equivalences can be characterized with ... More
Intuitionistic Logic Programming for SQL (Extended Abstract)Aug 11 2016Sep 22 2016Intuitionistic logic programming provides the notion of embedded implication in rule bodies, which can be used to reason about a current database modified by the antecedent. This can be applied to a system that translates SQL to Datalog to solve SQL WITH ... More
A new quantitative two weight theorem for the Hardy-Littlewood maximal operatorMay 02 2013A quantitative two weight theorem for the Hardy-Littlewood maximal operator is proved improving the known ones. As a consequence a new proof of the main results in [HP] and in [HPR12] is obtained which avoids the use of the sharp quantitative reverse ... More
On Normal Forms for Levi-flat hypersurfaces with an Isolated Line SingularityApr 09 2013Jan 27 2014We prove the existence of normal forms for some local real-analytic Levi-flat hypersurfaces with an isolated line singularity. We also give sufficient conditions for that a Levi-flat hypersurface with a complex line as singularity to be a pullback of ... More
On Levi-flat hypersurfaces tangent to holomorphic websSep 08 2011Sep 12 2011We investigate germs of real analytic Levi-flat hypersurfaces tangent to germs of codimension one holomorphic webs. We introduce the notion of first integrals for local webs. In particular, we prove that a $k$-web with finitely many invariant analytic ... More
Symplectic integrators in the realm of Hofer's geometryDec 31 2011Symplectic integrators constructed from Hamiltonian and Lie formalisms are obtained as symplectic maps whose flow follows the exact solution of a "sourrounded" Hamiltonian K = H + h^k H_1. Those modified Hamiltonians depends virtually on the time by h. ... More
Chordality properties and hyperbolicity on graphsMay 21 2015Let $G$ be a graph with the usual shortest-path metric. A graph is $\delta$-hyperbolic if for every geodesic triangle $T$, any side of $T$ is contained in a $\delta$-neighborhood of the union of the other two sides. A graph is chordal if every induced ... More
Banach spaces of linear operators and homogeneous polynomials without the approximation propertyMar 17 2016We present many examples of Banach spaces of linear operators and homogeneous polynomials without the approximation property, thus improving results of Dineen and Mujica [11] and Godefroy and Saphar [13].
A density-sensitive hierarchical clustering methodOct 23 2012Feb 06 2014We define a hierarchical clustering method: $\alpha$-unchaining single linkage or $SL(\alpha)$. The input of this algorithm is a finite metric space and a certain parameter $\alpha$. This method is sensitive to the density of the distribution and offers ... More
Euler classes and Bredon cohomology for groups with restricted families of finite subgroupsApr 17 2012Mar 12 2013We explore some of the special features with respect to Bredon cohomology of groups having all its finite subgroups either nilpotent or p-groups or cyclic p-groups. We get some results on dimensions and also a formula for the equivariant Euler class for ... More
On quasi-invariant curvesFeb 16 2018May 24 2018Quasi-invariant curves are used in the study of hedgehog dynamics. Denjoy-Yoccoz lemma is the preliminary step for Yoccoz's complex renormalization techniques for the study of linearization of analytic circle diffeomorphisms. We give a geometric interpretation ... More
A Bourgain-like property of Banach spaces with no copies of $c_0$Mar 29 2016We give a characterization of the existence of copies of $c_{0}$ in Banach spaces in terms of indexes. As an application, we deduce new proofs of James Distortion theorem and Bessaga-Pe{\l}czynski theorem about weakly unconditionally Cauchy series.
Dimension of Gibbs measures with infinite entropyDec 11 2018We study the Hausdorff dimension of Gibbs measures with infinite entropy with respect to maps of the interval with countably many branches. We show that under simple conditions, such measures are symbolic-exact dimensional, and provide an almost sure ... More
Kelly criterion for variable pay-offNov 13 2014We determine Kelly criterion for a game with variable pay-off. The Kelly fraction satisfies a fundamental integral equation and is smaller than the classical Kelly fraction for the same game with the constant average pay-off.
Ergodicity of laminations with singularities in Kähler surfacesApr 11 2013May 07 2013If $\mathcal{L}$ is a laminations with hyperbolic singularities, embedded in a compact homogeneous K\"ahler surface, without directed closed positive currents. Then, $\mathcal{L}$ has a unique directed positive harmonic current of mass one. This result ... More
Targets, local weak $σ$-Gibbs measures and a generalized Bowen dimension formulaMay 26 2016For a dynamical system, we study the set of points $\cal W$ whose orbit approximates any chosen point at certain specified rates. Our basic setting is that of left shift acting on topological Markov chains endowed with a local weak Gibbs measure. Our ... More
Generalized chordality, vertex separators and hyperbolicity on graphsAug 21 2017Let $G$ be a graph with the usual shortest-path metric. A graph is $\delta$-hyperbolic if for every geodesic triangle $T$, any side of $T$ is contained in a $\delta$-neighborhood of the union of the other two sides. A graph is chordal if every induced ... More
Equivariant absolute extensor property on hyperspaces of convex setsJan 12 2014Feb 07 2014Let G be a compact group acting on a Banach space L by means of linear isometries. The action of G on L induces a natural continuous action on cc(L), the hyperspace of all compact convex subsets of L endowed with the Hausdorff metric topology. The main ... More
On Normal Forms of Singular Levi-Flat Real Analytic HypersurfacesMar 25 2010Aug 04 2010Let $F(z)=\mathcal{R}e(P(z)) + h.o.t$ be such that $M=(F=0)$ defines a germ of real analytic Levi-flat at $0\in\mathbb{C}^{n}$, $n\geq{2}$, where $P(z)$ is a homogeneous polynomial of degree $k$ with an isolated singularity at $0\in\mathbb{C}^{n}$ and ... More
Mixed forward-backward stability of the two-level orthogonal Arnoldi method for quadratic problemsJul 04 2017We revisit the numerical stability of the two-level orthogonal Arnoldi (TOAR) method for computing an orthonormal basis of a second--order Krylov subspace associated with two given matrices. We show that the computed basis is close (on certain subspace ... More
The $L(\log L)^ε$ endpoint estimate for maximal singular integral operatorsMar 13 2015We prove in this paper the following estimate for the maximal operator $T^*$ associated to the singular integral operator $T$: $ \|T^*f\|_{L^{1,\infty}(w)} \lesssim \frac{1}{\epsilon} \int_{\mathbb{R}^n} |f(x)| M_{L(\log L)^{\epsilon}} (w)(x)dx$, for ... More
Towards exact symplectic integrators from Liouvillian formsSep 02 2015Dec 20 2015In this article we introduce a low order implicit symplectic integrator designed to follow the Hamiltonian flow as close as possible. This integrator is obtained by the method of Liouvillian forms proposed by the author in a previous work and does not ... More
On the Theory of Self-Adjoint Extensions of the Laplace-Beltrami Operator, Quadratic Forms and SymmetryAug 09 2013Sep 17 2013The main objective of this dissertation is to analyse thoroughly the construction of self-adjoint extensions of the Laplace-Beltrami operator defined on a compact Riemannian manifold with boundary and the role that quadratic forms play to describe them. ... More
A Kulikov-Type Classification Theorem for a One Parameter Family of K3-Surfaces Over a p-ADIC Field and a Good Reduction CriterionFeb 09 2018In this paper, we prove a $p$-adic analogous of the Kulikov-Persson-Pinkham classification theorem [Persson:1981wp] for the central fiber of a degeneration of $K3$-surfaces in terms of the nilpotency degree of the monodromy of the family. Namely, let ... More
The loop of formal power series with noncommutative coefficients under substitutionMar 12 2018The set of formal power series with coefficients in an associative but noncommutative algebra becomes a loop with the substitution product. We initiate the study of this loop by describing certain Lie and Sabinin algebras related to it. Some examples ... More
Directed harmonic currents for laminations on certain compact complex surfacesApr 10 2013Let $\mathcal{L}$ be a Lipschitz lamination by Riemann surfaces embedded in $M$. If $M$ is a complex torus, $\mathbb{CP}^1\times\mathbb{CP}^1$ or $\mathbb{T}^1\times\mathbb{CP}^1$ and there is no directed closed current then there exists a unique directed ... More
Some results on translating solitons of the mean curvature flowJan 27 2016In this article we prove two non-existence results for translating solitons of the mean curvature flow (translators for short) in $\mathbb{R}^{m+1}$. We also obtain an upper bound to the maximum height that a compact embedded translator in $\mathbb{R}^{3}$ ... More
Locality and universality in gravitational anomaly cancellationMay 30 2018We obtain necesary and sufficient conditions for gravitational anomaly cancellation. We show that perturbative gravitational anomalies can never be cancelled. In a similar way, in dimensions $n\neq3\operatorname{mod}4$ it is impossible to cancell global ... More
On the properties of $α$-unchaining single linkage hierarchical clusteringFeb 18 2014In the election of a hierarchical clustering method, theoretic properties may give some insight to determine which method is the most suitable to treat a clustering problem. Herein, we study some basic properties of two hierarchical clustering methods: ... More
Coends and the tensor product of $\mathcal{C}$-modulesAug 09 2016Oct 04 2016We give an introduction to the concept of Kan extensions, and study its relation with the notions of coend and adjoint functors. We state and prove in detail a well known formula to compute Kan extensions by using coends: a certain colimit related to ... More
Effects of excited state quantum phase transitions on system dynamicsApr 23 2016Aug 20 2016This work is concerned with the excited state quantum phase transitions (ESQPTs) defined in Ann.Phys. 323, 1106 (2008). In many-body models that exhibit such transitions, the ground state quantum phase transition (QPT) occurs in parallel with a singularity ... More
Fano resonances and Aharonov-Bohm effects in transport through a square quantum dot moleculeJun 26 2001Oct 28 2001We study the Aharonov-Bohm effect in a coupled 2$\times$2 quantum dot array with two-terminals. A striking conductance dip arising from the Fano interference is found as the energy levels of the intermediate dots are mismatched, which is lifted in the ... More
Li and Be depletion in metal-poor subgiantsDec 12 2005A sample of metal-poor subgiants has been observed with the UVES spectrograph at the Very Large Telescope and abundances of Li and Be have been determined. Typical signal-to-noise per spectral bin values for the co-added spectra are of the order of 500 ... More
Arrested dynamics of the dipolar hard-sphere modelMar 15 2019We report the combined results of molecular dynamics simulations and theoretical calculations concerning various dynamical arrest transitions in a model system representing a dipolar fluid, namely, N (softcore) rigid spheres interacting through a truncated ... More
Realization of quantum diffraction of a thermal fluxOct 02 2013Nov 20 2013The first evidence of the dc Josephson effect dates back to 1963 when J. S. Rowell measured the diffraction pattern of the critical current flowing through a single superconducting tunnel junction subjected to an in-plane magnetic field. Interference ... More
On the nature of the near-UV extended light in Seyfert galaxiesJul 01 2009We study the nature of the extended near-UV emission in the inner kiloparsec of a sample of 15 Seyfert galaxies which have both near-UV (F330W) and narrow band [OIII] high resolution Hubble images. For the majority of the objects we find a very similar ... More
Radiation Dose Charts for Long Geodetic and Polar Fligths with CARI-7ADec 04 2018We have calculated by using CARI-7A the effective and ambient radiation doses absorbed by a reference human phantom inside aircrafts with cruise speed, and averaged ascent/descent rates as presented by real airplanes such as: Airbus 380, Boeing 777, 787, ... More
Dilating Method for Cayley digraphs on finite Abelian groupsNov 16 2016A geometric method for obtaining an infinite family of Cayley digraphs of constant density on finite Abelian groups is presented. The method works for any given degree and it is based on consecutive dilates of a minimum distance diagram associated with ... More
The European Large Area ISO Survey VII: ROSAT observations of ELAIS sourcesNov 21 2001We present a cross-correlation between the ELAIS 15$\mu$m ISO survey with the {\it ROSAT} (0.1-2 keV) all-sky survey and the pointed observations WGACAT source catalogue. The resulting sample contains 15 objects. Optical spectroscopic identifications ... More
Overcoming efficiency constraints on blind quantum computationNov 18 2014Blind quantum computation allows a user to delegate a computation to an untrusted server while keeping the computation hidden. A number of recent works have sought to establish bounds on the communication requirements necessary to implement blind computation, ... More
The entangled accelerating universeAug 08 2009Using the known result that the nucleation of baby universes in correlated pairs is equivalent to spacetime squeezing, we show in this letter that there exists a T-duality symmetry between two-dimensional warp drives, which are physically expressible ... More
Structure of eigenstates and quench dynamics at an excited state quantum phase transitionJun 22 2015Nov 25 2015We study the structure of the eigenstates and the dynamics of a system that undergoes an excited state quantum phase transition (ESQPT). The analysis is performed for two-level pairing models characterized by a U(n+1) algebraic structure. They exhibit ... More
Detecting Faint Galaxies by Stacking at 24 micronDec 07 2005We stack Spitzer 24 micron images for ~7000 galaxies with 0.1<z<1 in the Chandra Deep Field South to probe the thermal dust emission in low-luminosity galaxies over this redshift range. Through stacking, we can detect mean 24 micron fluxes that are more ... More
The dependence of oxygen and nitrogen abundances on stellar mass from the CALIFA surveyAug 16 2016We analysed the optical spectra of HII regions extracted from a sample of 350 galaxies of the CALIFA survey. We calculated total O/H abundances and, for the first time, N/O ratios using the semi-empirical routine HII-CHI-mistry, which, according to P\'erez-Montero ... More
LO-phonon assisted polariton lasing in a ZnO based microcavityNov 30 2011Polariton relaxation mechanisms are analysed experimentally and theoretically in a ZnO-based polariton laser. A minimum lasing threshold is obtained when the energy difference between the exciton reservoir and the bottom of the lower polariton branch ... More
Fabrication and Optical Properties of a Fully Hybrid Epitaxial ZnO-Based Microcavity in the Strong Coupling RegimeMay 04 2011Jun 13 2011In order to achieve polariton lasing at room temperature, a new fabrication methodology for planar microcavities is proposed: a ZnO-based microcavity in which the active region is epitaxially grown on an AlGaN/AlN/Si substrate and in which two dielectric ... More
On the eigenvalue process of a matrix fractional Brownian motionJan 25 2014Jul 27 2014We investigate the process of eigenvalues of a symmetric matrix-valued process which upper diagonal entries are independent one-dimensional H\"older continuous Gaussian processes of order gamma in (1/2,1). Using the stochastic calculus with respect to ... More
Representations of pure symmetric automorphism groups of RAAGsOct 03 2017We study representations of the pure symmetric automorphism group $PAut(A_\Gamma)$ of a RAAG $A_\Gamma$ with defining graph $\Gamma$. We first construct a homomorphism from $PAut(A_\Gamma)$ to the direct product of a RAAG and a finite direct product of ... More
Using photo-ionisation models to derive carbon and oxygen gas-phase abundances in the rest UVJan 16 2017Mar 09 2017We present a new method to derive oxygen and carbon abundances using the ultraviolet (UV) lines emitted by the gas-phase ionised by massive stars. The method is based on the comparison of the nebular emission-line ratios with those predicted by a large ... More
American options under periodic exercise opportunitiesAug 14 2017Dec 24 2017In this paper, we study a version of the perpetual American call/put option where exercise opportunities arrive only periodically. Focusing on the exponential L\'evy models with i.i.d. exponentially-distributed exercise intervals, we show the optimality ... More
$F$-jumping and $F$-Jacobian ideals for hypersurfacesFeb 14 2013Apr 30 2013We introduce two families of ideals, $F$-jumping ideals and $F$-Jacobian ideals, in order to study the singularities of hypersurfaces in positive characteristic. Both families are defined using the $D$-modules $M_{\alpha}$ that were introduced by Blickle, ... More
Asymptotes of Space CurvesApr 25 2014May 15 2014In this paper, we generalize the results presented in [5] for the case of real algebraic space curves. More precisely, given an algebraic space curve C (parametrically or implicitly defined), we show how to compute the generalized asymptotes. The approach ... More
Separation axioms and covering dimension of asymmetric normed spacesMay 03 2018Jan 05 2019In this paper, we approach the question if some of the separation axioms are equivalent in the class of asymmetric normed spaces. In particular, we make a remark on a known theorem which states that every $T_1$ asymmetric normed space with compact closed ... More
A Class of Infinitely Divisible Multivariate and Matrix Gamma Distributions and Cone-valued Generalised Gamma ConvolutionsJan 06 2012Classes of multivariate and cone valued infinitely divisible Gamma distributions are introduced. Particular emphasis is put on the cone-valued case, due to the relevance of infinitely divisible distributions on the positive semi-definite matrices in applications. ... More
Double spend racesFeb 06 2017Feb 17 2017We correct the double spend race analysis given in Nakamoto's foundational Bitcoin article and give a closed-form formula for the probability of success of a double spend attack using the Regularized Incomplete Beta Function. We give a proof of the exponential ... More
On Profitability of Trailing MiningNov 22 2018We compute the revenue ratio of the Trail Stubborn mining strategy in the Bitcoin network and compare its profitability to other block-withholding strategies. We use for this martingale techniques and a classical analysis of the hiker problem. In this ... More
Model of the polarized foreground diffuse Galactic emissions from 33 to 353 GHzApr 16 2012We present 3D models of the Galactic magnetic field including regular and turbulent components, and of the distribution of matter in the Galaxy including relativistic electrons and dust grains. By integrating along the line of sight, we construct maps ... More