Results for "F. Xavier"

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A Seesaw Mechanism in the Higgs SectorJun 20 2006In this letter we revisit the seesaw Higgs mechanism. We show how a seesaw mechanism in a two Higgs doublets model can trigger the electroweak symmetry breaking if at least one of the eigenvalues of the squared mass matrix is negative. We then consider ... More
Quasars Probing Quasars VIII. The Physical Properties of the Cool Circumgalactic Medium Surrounding z ~ 2-3 Massive Galaxies Hosting QuasarsOct 20 2015Aug 12 2016We characterize the physical properties of the cool T ~10^4 K circumgalactic medium surrounding z ~2-3 quasar host galaxies, which are predicted to evolve into present day massive ellipticals. Using a statistical sample of 14 quasar pairs with projected ... More
Emergent Behavior in Multipartite Large Networks: Multi-virus EpidemicsJun 26 2013Epidemics in large complete networks is well established. In contrast, we consider epidemics in non-complete networks. We establish the fluid limit macroscopic dynamics of a multi-virus spread over a multipartite network as the number of nodes at each ... More
Fine Structure Constants in n-dimensional Physical Spaces through Dimensional AnalysisSep 07 2003We use Vaschy-Buckhingham Theorem as a systematic tool to build univocal n-dimensional extensions of the electric and gravitational fine structure constants and show that their ratio is dimensionally invariant. The results allow us to obtain the relative ... More
Quasars Probing Quasars IX. The Kinematics of the Circumgalactic Medium Surrounding z ~ 2 QuasarsMay 09 2017Mar 22 2018We examine the kinematics of the gas in the environments of galaxies hosting quasars at $z\sim2$. We employ 148 projected quasar pairs to study the circumgalactic gas of the foreground quasars in absorption. The sample selects foreground quasars with ... More
Quasars Probing Quasars VII. The Pinnacle of the Cool Circumgalactic Medium Surrounds Massive z~2 GalaxiesSep 22 2014We survey the incidence and absorption strength of the metal-line transitions CII 1334 and CIV from the circumgalactic medium (CGM) surrounding z~2 quasars, which act as signposts for massive dark matter halos M_halo~10^12.5 Msun. On scales of the virial ... More
Preorder Construct on Simple Undirected GraphsMar 09 2017We construct a novel preorder on the set of nodes of a simple undirected graph. We prove that the preorder (induced by the topology of the graph) is preserved, e.g., by the logistic dynamical system (both in discrete and continuous time). Moreover, the ... More
Epidemics in Multipartite Networks: Emergent DynamicsJun 28 2013Single virus epidemics over complete networks are widely explored in the literature as the fraction of infected nodes is, under appropriate microscopic modeling of the virus infection, a Markov process. With non-complete networks, this macroscopic variable ... More
The index of isolated umbilics on surfaces of non-positive curvatureApr 09 2014It is shown that if a $C^2$ surface $M\subset\mathbb R^3$ has negative curvature on the complement of a point $q\in M$, then the $\mathbb Z/2$-valued Poincar\'e-Hopf index at $q$ of either distribution of principal directions on $M-\{q\}$ is non-positive. ... More
D-ADMM: A Communication-Efficient Distributed Algorithm For Separable OptimizationFeb 13 2012Apr 22 2013We propose a distributed algorithm, named Distributed Alternating Direction Method of Multipliers (D-ADMM), for solving separable optimization problems in networks of interconnected nodes or agents. In a separable optimization problem there is a private ... More
Boundary versus bulk behavior of time-dependent correlation functions in one-dimensional quantum systemsFeb 04 2016May 25 2016We study the influence of reflective boundaries on time-dependent responses of one-dimensional quantum fluids at zero temperature beyond the low-energy approximation. Our analysis is based on an extension of effective mobile impurity models for nonlinear ... More
A nonlinear subgrid-scale model for large-eddy simulations of rotating turbulent flowsApr 29 2019Rotating turbulent flows form a challenging test case for large-eddy simulation (LES). We, therefore, propose and validate a new subgrid-scale (SGS) model for such flows. The proposed SGS model consists of a dissipative eddy viscosity term as well as ... More
PIBM: Particulate immersed boundary method for fluid-particle interaction problemsJul 25 2014It is well known that the number of particles should be scaled up to enable industrial scale simulation. The calculations are more computationally intensive when the motion of the surrounding fluid is considered. Besides the advances in computer hardware ... More
Thermodynamic Limit of Interacting Particle Systems over Time-varying Sparse Random NetworksFeb 26 2017We establish a functional weak law of large numbers for observable macroscopic state variables of interacting particle systems (e.g., voter and contact processes) over fast time-varying sparse random networks of interactions. We show that, as the number ... More
Deep Inference of Personality Traits by Integrating Image and Word Use in Social NetworksFeb 06 2018Social media, as a major platform for communication and information exchange, is a rich repository of the opinions and sentiments of 2.3 billion users about a vast spectrum of topics. To sense the whys of certain social user's demands and cultural-driven ... More
Sunyaev-Zel'dovich Effect ReviewJun 26 2000I review the present observational status of the SZ effect due to the Compton scattering of the 3K background on the hot electrons of clusters of galaxies. I raise the relevant issues from theoretical and X-ray aspects of the question that challenge the ... More
ANSIG - An Analytic Signature for Arbitrary 2D Shapes (or Bags of Unlabeled Points)Oct 19 2010In image analysis, many tasks require representing two-dimensional (2D) shape, often specified by a set of 2D points, for comparison purposes. The challenge of the representation is that it must not only capture the characteristics of the shape but also ... More
The Critical Behaviour of the Spin-3/2 Blume-Capel Model in Two DimensionsJan 19 1999The phase diagram of the spin-3/2 Blume-Capel model in two dimensions is explored by conventional finite-size scaling, conformal invariance and Monte Carlo simulations. The model in its $\tau$-continuum Hamiltonian version is also considered and compared ... More
Attend and Rectify: a Gated Attention Mechanism for Fine-Grained RecoveryJul 19 2018Jul 24 2018We propose a novel attention mechanism to enhance Convolutional Neural Networks for fine-grained recognition. It learns to attend to lower-level feature activations without requiring part annotations and uses these activations to update and rectify the ... More
Particulate immersed boundary method for complex fluid-particle interaction problems with heat transferFeb 04 2015In our recent work [H. Zhang, F.X. Trias, A. Oliva, D. Yang, Y. Tan, Y. Sheng. PIBM: Particulate immersed boundary method for fluid-particle interaction problems. Powder Technology. 272(2015), 1-13.], a particulate immersed boundary method (PIBM) for ... More
When parallel speedups hit the memory wallMay 03 2019After Amdahl's trailblazing work, many other authors proposed analytical speedup models but none have considered the limiting effect of the memory wall. These models exploited aspects such as problem-size variation, memory size, communication overhead, ... More
Principal values for Riesz transforms and rectifiabilityAug 01 2007Let $E\subset R^d$ with $H^n(E)<\infty$, where H^n stands for the $n$-dimensional Hausdorff measure. In this paper we prove that E is n-rectifiable if and only if the limit $$\lim_{\ve\to0}\int_{y\in E:|x-y|>\ve} \frac{x-y}{|x-y|^{n+1}} dH^n(y)$$ exists ... More
Requirements Management for Service Providers: the Case of Services for CitizensJan 19 2013Take the Internet of Things, a piece of cloud computing, a handful of smart cities, don't forget social platforms, flavour it with mobile technologies and ever-changing environments, shake it up and... voila! What a wonderful service! Oops! Wait a minute, ... More
Jump formulas for singular integrals and layer potentials on rectifiable setsNov 19 2018Nov 28 2018In this paper the jump formulas for the double layer potential and other singular integrals are proved for arbitrary rectifiable sets, by defining suitable non-tangential limits. The arguments are quite straightforward and only require some Calder\'on-Zygmund ... More
Representations semi-stables de torsion dans le cas peu ramifieJul 17 2004Oct 24 2004Let K be a local field of mixed characteristic not absolutely ramified. Fontaine-Laffaille theory gives a description of the torsion crystalline Z_p-representations of the absolute Galois group of K (p denotes the characteristic of the residual field). ... More
A new proof of the boundedness results for stable solutions to semilinear elliptic equationsJul 11 2019We consider the class of stable solutions to semilinear equations $-\Delta u=f(u)$ in a bounded smooth domain of $\mathbb{R}^n$. In dimensions $n\le 4$, an interior a priori $L^\infty$ bound for stable solutions is known to hold for all $C^1$ nonlinearities ... More
A new proof of the boundedness results for stable solutions to semilinear elliptic equationsJul 11 2019Jul 12 2019We consider the class of stable solutions to semilinear equations $-\Delta u=f(u)$ in a bounded smooth domain of $\mathbb{R}^n$. Since 2010 an interior a priori $L^\infty$ bound for stable solutions is known to hold in dimensions $n \leq 4$ for all $C^1$ ... More
Courants dynamiques pluripolairesMar 08 2010We show the existence of birational self-maps f of P^k which are algebraically stable with algebraic degree d, for which there is a unique positive closed (1,1) current T satisfying f^*T=d T and ||T||=1 and for which the current T gives total mass to ... More
Virial expansion with Feynman diagramsSep 22 2011We present a field theoretic method for the calculation of the second and third virial coefficients b2 and b3 of 2-species fermions interacting via a contact interaction. The method is mostly analytic. We find a closed expression for b3 in terms of the ... More
Simultaneous estimation of the mean and the variance in heteroscedastic Gaussian regressionJul 16 2008Dec 30 2008Let $Y$ be a Gaussian vector of $\mathbb{R}^n$ of mean $s$ and diagonal covariance matrix $\Gamma$. Our aim is to estimate both $s$ and the entries $\sigma_i=\Gamma_{i,i}$, for $i=1,...,n$, on the basis of the observation of two independent copies of ... More
BMO, H^1, and Calderon-Zygmund operators for non doubling measuresFeb 18 2000Given a Radon measure $\mu$ on $R^d$, which may be non doubling, we introduce a space of type BMO with respect to this measure. It is shown that many properties that hold when $\mu$ is doubling remain valid for the space BMO introduced in this paper, ... More
Uniform rectifiability, Calderon-Zygmund operators with odd kernel, and quasiorthogonalityMay 07 2008In this paper we study some questions in connection with uniform rectifiability and the $L^2$ boundedness of Calderon-Zygmund operators. We show that uniform rectifiability can be characterized in terms of some new adimensional coefficients which are ... More
Fano surfaces with 12 or 30 elliptic curvesJan 27 2010Feb 05 2010Curves of low genus on a surface carry important informations on that surface. We study the Fano surfaces of lines of cubic threefolds that contain 12 or 30 elliptic curves. We determine their Picard number and compute a basis of the N\'eron-Severi group ... More
Calderon-Zygmund capacities and Wolff potentials on Cantor setsJan 18 2010Jan 31 2013We show that, for some Cantor sets in R^d, the capacity g_s associated to the s-dimensional Riesz kernel x/|x|^{s+1} is comparable to the capacity C_{2(d-s)/3,3/2} from non linear potential theory. It is an open problem to show that, when s is positive ... More
Mass transport and uniform rectifiabilityMar 08 2011Aug 29 2011In this paper we characterize the so called uniformly rectifiable sets of David and Semmes in terms of the Wasserstein distance $W_2$ from optimal mass transport. To obtain this result, we first prove a localization theorem for the distance $W_2$ which ... More
On generalized Kummer surfaces and the orbifold Bogomolov-Miyaoka-Yau inequalityAug 30 2017Dec 29 2017A generalized Kummer surface $X=Km(T,G)$ is the resolution of a quotient of a torus $T$ by a finite group of symplectic automorphisms $G$. We complete the classification of generalized Kummer surfaces by studying the two last groups which have not been ... More
Bifurcation analysis in a frustrated nematic cellOct 25 2013Nov 13 2013Using Landau-de Gennes theory to describe nematic order, we study a frustrated cell consisting of nematic liquid crystal confined between two parallel plates. We prove the uniqueness of equilibrium states for a small cell width. Letting the cell width ... More
Squares in arithmetic progression over number fieldsSep 09 2009We show that there exists an upper bound for the number of squares in arithmetic progression over a number field that depends only on the degree of the field. We show that this bound is 5 for quadratic fields, and also that the result generalizes to $k$-powers ... More
Regularity of C^1 and Lipschitz domains in terms of the Beurling transformJan 25 2012Let D be a bounded planar C^1 domain, or a Lipschitz domain "flat enough", and consider the Beurling transform of 1_D, the characteristic function of D. Using a priori estimates, in this paper we solve the following free boundary problem: if the Beurling ... More
Polynomial parametrizations of length $4$ Büchi sequencesAug 18 2010B\"uchi's problem asks whether there exists a positive integer $M$ such that any sequence $(x_n)$ of at least $M$ integers, whose second difference of squares is the constant sequence $(2)$, satisifies $x_n^2=(x+n)^2$ for some $x\in\Z$. A positive answer ... More
Abelian varieties with many endomorphisms and their absolutely simple factorsFeb 04 2011We characterize the abelian varieties arising as absolutely simple factors of GL2-type varieties over a number field k. In order to obtain this result, we study a wider class of abelian varieties: the k-varieties A/k satisfying that $\End_k^0(A)$ is a ... More
An alternative view on the electroweak interactionsAug 23 2010We discuss an alternative to the Higgs mechanism which leads to gauge invariant masses for the electroweak bosons. The key idea is to reformulate the gauge invariance principle which, instead of being applied as usual at the level of the action, is applied ... More
Yang-Mills Theories on Noncommutative Space-TimeJan 27 2004We describe some recent progress in our understanding of Yang-Mills theories formulated on noncommutative spaces and in particular how to formulate the standard model on such spaces.
A review of Quantum Gravity at the Large Hadron ColliderMay 11 2010The aim of this article is to review the recent developments in the phenomenology of quantum gravity at the Large Hadron Collider. We shall pay special attention to four-dimensional models which are able to lower the reduced Planck mass to the TeV region ... More
Minimal Grand Unification Model in an Anthropic LandscapeJun 28 2004It has been recently pointed out by Arkani-Hamed and Dimopoulos that if the universe is a landscape of vacua, and if therefore fine-tuning is not a valid guidance principle for searching for physics beyond the standard model, supersymmetric unification ... More
Virtual Black Holes, Remnants and the Information ParadoxDec 19 2014We revisit the question of the contributions of Planckian quantum black holes in general and of remnants in particular to low energy physics observables. As long as quantum gravity preserves the symmetries of the low energy effective field theory, we ... More
On the 1+3 Formalism in General RelativityMay 24 2014We present in this paper the formalism for the splitting of a four-dimensional Lorentzian manifold by a set of time-like integral curves. Introducing the geometrical tensors characterizing the local spatial frames induced by the congruence (namely, the ... More
On the complexity of strongly connected components in directed hypergraphsDec 06 2011Feb 12 2013We study the complexity of some algorithmic problems on directed hypergraphs and their strongly connected components (SCCs). The main contribution is an almost linear time algorithm computing the terminal strongly connected components (i.e. SCCs which ... More
Singletons and their maximal symmetry algebrasNov 19 2011Jan 02 2012Singletons are those unitary irreducible modules of the Poincare or (anti) de Sitter group that can be lifted to unitary modules of the conformal group. Higher-spin algebras are the corresponding realizations of the universal enveloping algebra of the ... More
Effective theory for quantum gravityAug 28 2013In this paper, we discuss an effective theory for quantum gravity and discuss the bounds on the parameters of this effective action. In particular we show that measurement in pulsars binary systems are unlikely to improve the bounds on the coefficients ... More
Some properties of the nematic radial hedgehog in Landau-de Gennes' theoryDec 05 2012In the Landau-de Gennes theoretical framework of a $Q -tensor description of nematic liquid crystals, we consider a radial hedgehog defect with strong anchoring conditions in a ball $B \subset \mathbb{R}^3$ . We show that the scalar order parameter is ... More
Classical and Quantum Phenomenology in Radiation by Relativistic Electrons in Matter or in External FieldsDec 05 2014Phenomenological aspects of radiation by relativistic electrons in external field, in matter or the vicinity of matter are reviewed, among which: infrared divergence, coherence length effects, shadowing, enhancement in aligned crystals, quantum recoil ... More
Review of double beta experimentsOct 19 2012This paper is the first part of the manuscript written in April 2012 for my academic Accreditation to supervise research. It offers a review of the double beta experimental techniques. My purpose is to detail, for each technique, the different origins ... More
Cycles of links and fixed points for orientation preserving homeomorphisms of the open unit diskAug 10 2012Michael Handel proved in Handel (1999) the existence of a fixed point for an orientation preserving homeomorphism of the open unit disk that can be extended to the closed disk, provided that it has points whose orbits form an oriented cycle of links at ... More
Search for B+ to D+ K(*)0 decays with the BaBar experimentDec 07 2010We report a search for the rare decays B+ to D+ K0 and B+ to D+ K*0 in an event sample of approximately 465 million BBbar pairs collected with the BaBar detector at the PEP-II asymmetric-energy e+e- collider at SLAC. We find no significant evidence for ... More
L'application cotangente des surfaces de type generalFeb 24 2009We study surfaces of general type $S$ whose cotangent sheaf is generated by its global sections. We define a map called the cotangent map of $S$ that enables us to understand the obstructions to the ampleness of the cotangent sheaf of $S$. These obstructions ... More
Characterization of the atomic space $H^1$ for non doubling measures in terms of a grand maximal operatorMay 06 2000Let $\mu$ be a Radon measure on $R^d$, which may be non doubling. The only condition that $\mu$ must satisfy is $\mu(B(x,r))\leq C r^n$, for all $x,r$ and for some fixed $0<n\leq d$. Recently we introduced spaces of type $BMO(\mu)$ and $H^1(\mu)$ which ... More
Quasiconformal distortion of Hausdorff measuresJul 28 2009Sep 09 2009In this paper we prove that if f is a planar K-quasiconformal map and 0<t<2, t' = 2t/(2K-Kt+t), then f transforms sets of finite (t')-Hausdorff measure into sets of finite t-Hausdorff measure. We also prove the following more quantitative statement: If ... More
Regularity of minimizers of semilinear elliptic problems up to dimension fourSep 25 2009Sep 28 2009We consider the class of semi-stable solutions to semilinear equations $-\Delta u=f(u)$ in a bounded smooth domain $\Omega$ of $R^n$ (with $\Omega$ convex in some results). This class includes all local minimizers, minimal, and extremal solutions. In ... More
The zeta functions of the Fano surfaces of cubic threefoldsApr 15 2013Mar 14 2015We give an algorithm to compute the zeta function of the Fano surface of lines of a smooth cubic threefold $F$ into $\mathbb{P}^4$ defined over a finite field. We obtain some examples of Fano surfaces with supersingular reduction.
Quotients of Fano SurfacesMar 24 2011Feb 09 2012Fano surfaces parametrize the lines of smooth cubic threefolds. In this paper, we study their quotients by some of their automorphism sub-groups. We obtain in that way some interesting surfaces of general type.
Fields of definition of building blocks with quaternionic multiplicationMay 27 2009Sep 13 2011This paper investigates the fields of definition up to isogeny of the abelian varieties called building blocks. A result of Ribet characterizes the fields of definition of these varieties together with their endomorphisms, in terms of a Galois cohomology ... More
Issues in Electric-Magnetic DualitySep 20 2002Chapters : 1. Introduction to electric-magnetic duality 2. Classical duality in bosonic brane electrodynamics 3. Massless spin two gauge theory 4. Duality-symmetric actions and chiral forms 5. BRST quantization of duality-symmetric Maxwell's theory 6. ... More
Characterization of $n$-rectifiability in terms of Jones' square function: Part IJan 07 2015Nov 12 2017In this paper it is shown that if $\mu$ is a finite Radon measure in $\mathbb R^d$ which is $n$-rectifiable and $1\leq p\leq 2$, then $$\int_0^\infty \beta_{\mu,p}^n(x,r)^2\,\frac{dr}r<\infty \quad {for $\mu$-a.e. $x\in\mathbb R^d$,}$$ where $$\beta_{\mu,p}^n(x,r) ... More
Dualité de Cartier et modules de BreuilNov 16 2005Let O\_K be a complete discrete valuation ring. Denote by K its fractions field and by k its residue field. Assume that k is of characteristic p>0 and perfect. Breuil gives an anti-equivalence between the category of finite flat O\_K-group schemes killed ... More
Well-posedness for a higher order nonlinear Schrodinger equation in Sobolev spaces of negative indicesJul 31 2003We prove that, the initial value problem associated to u_{t} + i\alphau_{xx} + \beta u_{xxx} + i\gamma |u|^{2}u = 0, x,t \in R, is locally well-posed in Sobolev spaces H^{s} for s>-1/4.
Variance optimal hedging with application to Electricity marketsNov 10 2017Aug 28 2018In Electricity markets, illiquidity, transaction costs and market price characteristics prevent managers to replicate exactly contracts. A residual risk is always present and the hedging strategy depends on a risk criterion chosen. We present an algorithm ... More
Fibre derivatives: some applications to singular lagrangiansJul 27 2000The fibre derivative of a bundle map is studied in detail. In the particular case of a real function, several constructions useful to study singular lagrangians are presented. Some applications are given; in particular, a geometric construction useful ... More
On Searches for Gravitational Dark Matter with Quantum SensorsJul 12 2019The possibility of searching for dark matter with quantum sensors has recently received a lot of attention. In this short paper, we discuss the possibility of searching for gravitational dark matter with quantum sensors and identify a very narrow window ... More
On the number of equilibria with a given number of unstable directionsSep 12 2017We compute the large-dimensional asymptotics for the average number of equilibria with a fixed number of unstable directions for random Gaussian ODEs on a sphere. We also discuss the effects that the value of the Lagrange multiplier of the vector field ... More
Genus 2 curve configurations on Fano surfacesFeb 24 2010We study the configurations of genus 2 curves on the Fano surfaces of cubic threefolds. We establish a link between some involutive automorphisms acting on such a surface S and genus 2 curves on S. We give a partial classification of the Fano surfaces ... More
Rectifiable measures, square functions involving densities, and the Cauchy transformAug 29 2014Jan 31 2015This paper is devoted to the proof of two related results. The first one asserts that if $\mu$ is a Radon measure in $\mathbb R^d$ satisfying $$\limsup_{r\to 0} \frac{\mu(B(x,r))}{r}>0\quad \text{ and }\quad \int_0^1\left|\frac{\mu(B(x,r))}{r} - \frac{\mu(B(x,2r))}{2r}\right|^2\,\frac{dr}r< ... More
Schémas en groupes et poids de Diamond-SerreMay 09 2007This note is a correction of (statement and proof of) proposition 3.3.1 of Toby Gee's preprint intitled *On the weights of mod p Hilbert modular forms*. The aim is to compare Galois representations arising from extensions of some group schemes (over the ... More
Adaptive sparse grids for time dependent Hamilton-Jacobi-Bellman equations in stochastic controlAug 19 2014We introduce some sparse grids interpolations used in Semi-Lagrangian schemes for linear and fully non-linear diffusion Hamilton Jacobi Bellman equations arising in stochastic control. We prove that the method introduced converges toward the viscosity ... More
Monte Carlo for high-dimensional degenerated Semi Linear and Full Non Linear PDEsMay 14 2018We extend a recently developed method to solve semi-linear PDEs to the case of a degenerated diffusion. Being a pure Monte Carlo method it does not suffer from the so called curse of dimensionality and it can be used to solve problems that were out of ... More
Trivial points on towers of curvesJan 12 2012We define and study trivial points on towers of curves over number fields, and we show their finiteness in some cases. We relate these to the unboundeness of the gonality of the curves, which we show under some hypothesis. The problem is related to recent ... More
Regular graphs of large girth and arbitrary degreeOct 24 2011Sep 21 2013For every integer d > 9, we construct infinite families {G_n}_n of d+1-regular graphs which have a large girth > log_d |G_n|, and for d large enough > 1,33 log_d |G_n|. These are Cayley graphs on PGL_2(q) for a special set of d+1 generators whose choice ... More
The Benefits of Low Operating Voltage Devices to the Energy Efficiency of Parallel SystemsAug 13 2017Programmable circuits such as general-purpose processors or FPGAs have their end-user energy efficiency strongly dependent on the program that they execute. Ultimately, it is the programmer's ability to code and, in the case of general purpose processors, ... More
A Deep Narrowband Imaging Search for CIV and He II Emission from Ly$α$ BlobsJul 10 2014We conduct a deep narrow-band imaging survey of 13 Ly$\alpha$ blobs (LABs) located in the SSA22 proto-cluster at z~3.1 in the CIV and HeII emission lines in an effort to constrain the physical process powering the Ly$\alpha$ emission in LABs. Our observations ... More
Analysis of ProNaOS submillimeter maps in the M42 Orion Nebula - Temperature - spectral index inverse correlation in several regionsFeb 06 2001We have mapped with the French submillimeter balloon-borne telescope ProNaOS the thermal emission of the dust in the M42 Orion Nebula. The map obtained is 50' by 40' with an angular resolution of about 3' in the four efficient wavelengths 200 $\mic$, ... More
Experimental quantum randomness generation invulnerable to the detection loopholeOct 13 2014Oct 28 2014Random numbers are essential for multiple applications, including cryptography, financial security, digital rights management and scientific simulations. However, producing random numbers from a finite state machine, such as a classical computer, is impossible. ... More
Dust during the ReionizationOct 06 2003Jun 03 2004The possibility that population III stars have reionized the Universe at redshifts greater than 6 has recently gained momentum with WMAP polarization results. Here we analyse the role of early dust produced by these stars and ejected into the intergalactic ... More
Exploring EEG for Object Detection and RetrievalApr 09 2015This paper explores the potential for using Brain Computer Interfaces (BCI) as a relevance feedback mechanism in content-based image retrieval. We investigate if it is possible to capture useful EEG signals to detect if relevant objects are present in ... More
Object Segmentation in Images using EEG SignalsAug 19 2014This paper explores the potential of brain-computer interfaces in segmenting objects from images. Our approach is centered around designing an effective method for displaying the image parts to the users such that they generate measurable brain reactions. ... More
Anderson localization of light: Strong dependence with incident angleMay 25 2017Oct 01 2018This paper studies the transport of light for different incidence angles in a strongly disordered optical medium composed by core-shell nanoparticles (TiO2@Silica) suspended in ethanol solution. A decrease of optical conductance and an increase of absorption ... More
On global solutions to semilinear elliptic equations related to the one-phase free boundary problemNov 07 2018Motivated by its relation to models of flame propagation, we study globally Lipschitz solutions of $\Delta u=f(u)$ in $\mathbb{R}^n$, where $f$ is smooth, non-negative, with support in the interval $[0,1]$. In such setting, any "blow-down" of the solution ... More
Constraint algorithm for singular field theories in the $k$-cosymplectic frameworkDec 20 2018The aim of this paper is to develop a constraint algorithm for singular classical field theories in the framework of $k$-cosymplectic geometry. Since these field theories are singular, we need to introduce the notion of $k$-precosymplectic structure, ... More
Sharp isoperimetric inequalities via the ABP methodApr 05 2013Apr 15 2013We prove some old and new isoperimetric inequalities with the best constant using the ABP method applied to an appropriate linear Neumann problem. More precisely, we obtain a new family of sharp isoperimetric inequalities with weights (also called densities) ... More
Dynamical instability criterion for circular (vorton) string loopsJun 12 2003Dynamic perturbation equations are derived for a generic stationary state of an elastic string model -- of the kind appropriate for representing a superconducting cosmic string -- in a flat background. In the case of a circular equilibrium (i.e. vorton) ... More
High frequency gravitational waves generation in laser plasma interactionJan 08 2018Estimates of the emitted power and the metric perturbation of the gravitational waves generated in laser plasma interaction are performed. The expected intensities are too low to be detected with the present day instruments.
On the hyperbolicity of surfaces of general type with small $c_1 ^2$Jan 27 2012Jul 16 2012Surfaces of general type with positive second Segre number $s_2:=c_1^2-c_2>0$ are known by results of Bogomolov to be quasi-hyperbolic i.e. with finitely many rational and elliptic curves. These results were extended by McQuillan in his proof of the Green-Griffiths ... More
A Riemannian Bieberbach estimateMay 15 2009The Bieberbach estimate, a pivotal result in the classical theory of univalent functions, states that any injective holomorphic function $f$ on the open unit disc $D$ satisfies $|f"(0)|\leq 4 |f'(0)|$. We generalize the Bieberbach estimate by proving ... More
Chern slopes of simply connected complex surfaces of general type are dense in [2,3]Feb 24 2014Nov 09 2014We prove that for any number $r$ in $[2,3]$, there are spin (resp. non-spin minimal) simply connected complex surfaces of general type $X$ with $c_1^2(X)/c_2(X)$ arbitrarily close to $r$. In particular, this shows the existence of simply connected surfaces ... More
Towards an efficient deep learning model for musical onset detectionJun 18 2018Jun 19 2018In this paper, we propose an efficient and reproducible deep learning model for musical onset detection (MOD). We first review the state-of-the-art deep learning models for MOD, and identify their shortcomings and challenges: (i) the lack of hyper-parameter ... More
Singing voice phoneme segmentation by hierarchically inferring syllable and phoneme onset positionsJun 05 2018In this paper, we tackle the singing voice phoneme segmentation problem in the singing training scenario by using language-independent information -- onset and prior coarse duration. We propose a two-step method. In the first step, we jointly calculate ... More
Modular abelian varieties over number fieldsMay 15 2009Aug 31 2012The main result of this paper is a characterization of the abelian varieties $B/K$ defined over Galois number fields with the property that the zeta function $L(B/K;s)$ is equivalent to the product of zeta functions of non-CM newforms for congruence subgroups ... More
Models of mu_{p^2,K} over a discrete valuation ringJan 09 2010Let R be a discrete valuation ring with residue field of characteristic p>0. Let K be its fraction field. We prove that any finite and flat R-group scheme, isomorphic to \mu_{p^2,K} on the generic fiber, is the kernel in a short exact sequence which generically ... More
Coinfection in a stochastic model for bacteriophage systemsFeb 20 2017A system modeling bacteriophage treatments with coinfections in a noisy context is analyzed. We prove that in a small noise regime, the system converges in the long term to a bacteria free equilibrium. Moreover, we compare the treatment with coinfection ... More
Combinatoire du point de croixJan 24 2010This paper deals with a popular form of counted-thread embroidery: the cross-stitch. More precisely, we are interested in the minimal length of embroidery thread one need to fill a given picture. We give a complete answer to this problem for 4-connexe ... More
Shatter functions with polynomial growth ratesJan 23 2017We study how a single value of the shatter function of a set system restricts its asymptotic growth. Along the way, we refute a conjecture of Bondy and Hajnal which generalizes Sauer's Lemma.