Results for "Jean-Francois Donati"

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Pollux: a stable weak dipolar magnetic field but no planet ?Oct 25 2013Pollux is considered as an archetype of a giant star hosting a planet: its radial velocity (RV) presents sinusoidal variations with a period of about 590 d, which have been stable for more than 25 years. Using ESPaDOnS and Narval we have detected a weak ... More
Quaternionic Gamma functions and their logarithmic derivatives as spectral functionsApr 12 1999Nov 10 2000We establish Connes's local trace formula (related to the explicit formulae of number theory) for the quaternions. This is done as an application of a study of the central operator H = log(|x|) + log(|y|) in the context of invariant harmonic analysis. ... More
Diffusion processes with weak constraint through penalization approximationApr 05 2017Apr 19 2017In this paper, we investigate the construction of a diffusion process whose time-marginal densities are constrained to belong to a given set at all time. The construction is obtained from a penalization approximation to the constraint set, acting on the ... More
Gravitational Waves from the Non-Perturbative Decay of Condensates along Supersymmetric Flat DirectionsFeb 16 2009Sep 01 2009It has recently been shown that specific non-perturbative effects may lead to an explosive decay of flat direction condensates in supersymmetric theories. We confirm explicitly the efficiency of this process with lattice simulations: after few rotations ... More
Geodesics in large planar maps and in the Brownian mapApr 18 2008May 30 2008We study geodesics in the random metric space called the Brownian map, which appears as the scaling limit of large planar maps. In particular, we completely describe geodesics starting from the distinguished point called the root, and we characterize ... More
Generating Compatibility Conditions in Mathematical PhysicsNov 23 2018The search for generating compatibility conditions (CC) for a given operator is a very recent problem met in General Relativity in order to study the Killing operator for various standard useful metrics (Minkowski, Schwarschild and Kerr). In this paper, ... More
Algebraic Analysis and Mathematical PhysicsJun 13 2017This paper aims to revisit the mathematical foundations of both General Relativity and Electromagnetism after one century, in the light of the formal theory of systems of partial differential equations and Lie pseudogroups (D.C. Spencer, 1970) or Algebraic ... More
Correspondance locale de Langlands et monodromie des espaces de DrinfeldJul 05 2004The conjecture stated by Carayol in [{\em Non-abelian Lubin-Tate theory.} Automorphic forms, Shimura varieties and $L$-functions, vol II: 15--39, Academic Press,1990] predicted that the {\em supercuspidal part} of the l-adic cohomology of the moduli spaces ... More
Theorie de Lubin-Tate non-abelienne et representations elliptiquesApr 03 2006Harris and Taylor proved that the supercuspidal part of the cohomology of the Lubin-Tate tower realizes both the local Langlands and Jacquet-Langlands correspondences, as conjectured by Carayol. Recently, Boyer computed the remaining part of the cohomology ... More
Quasistatic evolution of a brittle thin filmApr 26 2006This paper deals with the quasistatic crack growth of a homogeneous elastic brittle thin film. It is shown that the quasistatic evolution of a three-dimensional cylinder converges, as its thickness tends to zero, to a two-dimensional quasistatic evolution ... More
The Explicit Formula and a PropagatorSep 21 1998Nov 22 1998I give a new derivation of the Explicit Formula for the general number field K, which treats all primes in exactly the same way, whether they are discrete or archimedean, and also ramified or not. In another token, I advance a probabilistic interpretation ... More
Scattering on the p-adic field and a trace formulaJan 12 1999Feb 01 1999I apply the set-up of Lax-Phillips Scattering Theory to a non-archimedean local field. It is possible to choose the outgoing space and the incoming space to be Fourier transforms of each other. Key elements of the Lax-Phillips theory are seen to make ... More
Spectral Analysis of the local Conductor OperatorNov 07 1998Nov 22 1998The conductor operator acts on a function through multiplying it with the logarithm of the norm of the variable both in position and in momentum space and adding the outcomes. It makes sense at each completion of an arbitrary number field and arose in ... More
Mesures limites pour l'equation de Helmholtz dans le cas non captifJul 05 2007Cet article est consacre a l'etude des mesures limites associees a la solution de l'equation de Helmholtz avec un terme source se concentrant en un point. Le potentiel est suppose regulier et l'operateur non-captif. La solution de l'equation de Schrodinger ... More
Stable and Unstable Regimes of Mass Accretion onto RW Aur AFeb 24 2016Apr 18 2016We present monitoring observations of the active T Tauri star RW Aur, from 2010 October to 2015 January, using optical high-resolution (R>10000) spectroscopy with CFHT-ESPaDOnS. Optical photometry in the literature shows bright, stable fluxes over most ... More
Low-lying eigenvalues of semiclassical Schrödinger operator with degenerate wellsFeb 08 2018In this article, we consider the semiclassical Schr\"odinger operator $P = - h^{2} \Delta + V$ in $\mathbb{R}^{d}$ with confining non-negative potential $V$ which vanishes, and study its low-lying eigenvalues $\lambda_{k} ( P )$ as $h \to 0$. First, we ... More
A pinching theorem for the first eigenvalue of the laplacian on hypersurface of the euclidean spaceSep 18 2006In this paper, we give pinching Theorems for the first nonzero eigenvalue $\lambda$ of the Laplacian on the compact hypersurfaces of the Euclidean space. Indeed, we prove that if the volume of $M$ is 1 then, for any $\epsilon>0$, there exists a constant ... More
Geometric optics for surface waves in nonlinear elasticityApr 15 2016This work is devoted to the analysis of high frequency solutions to the equations of nonlinear elasticity in a half-space. We consider surface waves (or more precisely, Rayleigh waves) arising in the general class of isotropic hyperelastic models, which ... More
Changing the branching mechanism of a continuous state branching process using immigrationSep 19 2006Oct 15 2007We construct a continuous state branching process with immigration (CBI) whose immigration depends on the CBI itself and we recover a continuous state branching process (CB). This provides a dual construction of the pruning at nodes of CB introduced by ... More
Antichains for the Automata-Based Approach to Model-CheckingFeb 23 2009Mar 02 2009We propose and evaluate antichain algorithms to solve the universality and language inclusion problems for nondeterministic Buechi automata, and the emptiness problem for alternating Buechi automata. To obtain those algorithms, we establish the existence ... More
Modules formels locaux de feuilletages holomorphesFeb 16 2004We give a complete list of formal invariants for a large class of formal differential 1-forms $\w \in \Bbb C [[ x, y]]dx + \Bbb C [[ x, y]]dy$. \indent A $\hat{SL}$-equisingular deformation is an equireducible deformation which leaves invariant both the ... More
A variational approach to the local character of G-closure: the convex caseMar 14 2007Aug 21 2007This article is devoted to characterize all possible effective behaviors of composite materials by means of periodic homogenization. This is known as a $G$-closure problem. Under convexity and $p$-growth conditions ($p>1$), it is proved that all such ... More
On the Hausdorff dimension of CAT($κ$) surfacesMar 01 2016We prove that a closed surface with a CAT($\kappa$) metric has Hausdorff dimension = 2, and that there are uniform upper and lower bounds on the two-dimensional Hausdorff measure of small metric balls. We also discuss a connection between this uniformity ... More
Homogenization of variational problems in manifold valued BV-spacesApr 03 2008Nov 04 2008This paper extends the result of \cite{BM} on the homogenization of integral functionals with linear growth defined for Sobolev maps taking values in a given manifold. Through a $\Gamma$-convergence analysis, we identify the homogenized energy in the ... More
Lagrangian stochastic models with specular boundary conditionApr 22 2013Dec 09 2014In this paper, we prove the well-posedness of a conditional McKean Lagrangian stochastic model endowing the specular boundary condition and the mean no--permeability condition in smooth bounded confinement domain D. This result extend our previous work, ... More
Homogenization of variational problems in manifold valued Sobolev spacesDec 11 2007Apr 22 2008Homogenization of integral functionals is studied under the constraint that admissible maps have to take their values into a given smooth manifold. The notion of tangential homogenization is defined by analogy with the tangential quasiconvexity introduced ... More
Eigenvalue pinching and application to the stability and the almost umbilicity of hypersurfacesSep 06 2007Feb 14 2011In this paper we give pinching theorems for the first nonzero eigenvalue of the Laplacian on the compact hypersurfaces of ambient spaces with bounded sectional curvature. As application we deduce rigidity results for stable constant mean curvature hypersurfaces ... More
Superstructures par agrégation contrôlée de nanocolloïdes: caractérisation structurale par diffusion de neutrons aux petits angles et simulation numériqueFeb 01 2011The complexation of micelles or charged nanoparticles with neutral-charged block copolymers in aqueous solutions leads to the formation of colloidal superstructures also termed 'colloidal complexes'. Their primary interest relies in their monodispersity ... More
The first eigenvalue of Dirac and Laplace operators on surfacesSep 18 2006Let $(M,g,\sigma)$ be a compact Riemmannian surface equipped with a spin structure $\sigma$. For any metric $\tilde{g}$ on $M$, we denote by $\mu\_1(\tilde{g})$ (resp. $\lambda\_1(\tilde{g})$) the first positive eigenvalue of the Laplacian (resp. the ... More
3D-2D analysis of a thin film with periodic microstructureApr 26 2006The purpose of this article is to study the behavior of a heterogeneous thin film whose microstructure oscillates on a scale that is comparable to that of the thickness of the domain. The argument is based on a 3D-2D dimensional reduction through a $\Gamma$-convergence ... More
Semiclassical estimates of the cut-off resolvent for trapping perturbationsJan 26 2012Sep 21 2012This paper is devoted to the study of a semiclassical "black box" operator $P$. We estimate the norm of its resolvent truncated near the trapped set by the norm of its resolvent truncated on rings far away from the origin. For $z$ in the unphysical sheet ... More
Local energy decay for several evolution equations on asymptotically euclidean manifoldsAug 13 2010Let P be a long range metric perturbation of the Euclidean Laplacian on R^d, d>1. We prove local energy decay for the solutions of the wave, Klein-Gordon and Schroedinger equations associated to P. The problem is decomposed in a low and high frequency ... More
Resolvent smoothness and local decay at low energies for the standard model of non-relativistic QEDApr 15 2011We consider an atom interacting with the quantized electromagnetic field in the standard model of non-relativistic QED. The nucleus is supposed to be fixed. We prove smoothness of the resolvent and local decay of the photon dynamics for quantum states ... More
Charge transport in purple membrane monolayers: A sequential tunneling approachMay 04 2011Current voltage (I-V) characteristics in proteins can be sensitive to conformational change induced by an external stimulus (photon, odour, etc.). This sensitivity can be used in medical and industrial applications besides shedding new light in the microscopic ... More
An explicit Euler scheme with strong rate of convergence for financial SDEs with non-Lipschitz coefficientsMay 14 2014Apr 10 2016We consider the approximation of stochastic differential equations (SDEs) with non-Lipschitz drift or diffusion coefficients. We present a modified explicit Euler-Maruyama discretisation scheme that allows us to prove strong convergence, with a rate. ... More
Formal and Informal Methods for Multi-Core Design Space ExplorationJun 09 2014We propose a tool-supported methodology for design-space exploration for embedded systems. It provides means to define high-level models of applications and multi-processor architectures and evaluate the performance of different deployment (mapping, scheduling) ... More
Springer theory in braid groups and the Birman-Ko-Lee monoidOct 26 2000We state a conjecture about centralizers of certain roots of central elements in braid groups, and check it for Artin braid groups and some other cases. Our proof makes use of results by Birman-Ko-Lee; we give a new intrinsic account of these results. ... More
Future supernovae data and quintessence modelsJul 16 2002Feb 14 2003The possibility to unambiguously determine the equation-of-state of the cosmic dark energy with existing and future supernovae data is investigated. We consider four evolution laws for this equation-of-state corresponding to four quintessential models, ... More
Pruning Galton-Watson Trees and Tree-valued Markov ProcessesJul 02 2010Feb 07 2011We present a new pruning procedure on discrete trees by adding marks on the nodes of trees. This procedure allows us to construct and study a tree-valued Markov process $\{{\cal G}(u)\}$ by pruning Galton-Watson trees and an analogous process $\{{\cal ... More
Comparison of integral structures on spaces of modular forms of weight two, and computation of spaces of forms mod 2 of weight one, with appendices by Jean-Francois Mestre and Gabor WieseDec 01 2003Two integral structures on the Q-vector space of modular forms of weight two on X_0(N) are compared at primes p exactly dividing N. When p=2 and N is divisible by a prime that is 3 mod 4, this comparison leads to an algorithm for computing the space of ... More
Relations between Potts and RSOS models on a torusJul 19 2005We study the relationship between Q-state Potts models and staggered RSOS models of the A\_{p-1} type on a torus, with sqrt(Q)=2 cos(pi / p). In general the partition functions of these models differ due to clusters of non-trivial topology. However we ... More
Resolvent and scattering matrix at the maximum of the potentialNov 06 2007We study the microlocal structure of the resolvent of the semi-classical Schrodinger operator with short range potential at an energy which is a unique non-degenerate global maximum of the potential. We prove that it is a semi-classical Fourier integral ... More
Homology of spaces of regular loops in the sphereNov 20 2008Mar 27 2009In this paper we compute the singular homology of the space of immersions of the circle into the $n$-sphere. Equipped with Chas-Sullivan's loop product these homology groups are graded commutative algebras, we also compute these algebras. We enrich Morse ... More
Escape probabilities for branching Brownian motion among mild obstaclesMar 19 2010Jan 17 2011We derive asymptotics for the quenched probability that a critical branching Brownian motion killed at a small rate in Poissonian obstacles exits a large domain. Results are formulated in terms of the solution to a semilinear partial differential equation ... More
Stochastic integral representation and regularity of the density for the Exit measure of super-Brownian motionMar 25 2005This paper studies the regularity properties of the density of the exit measure for super-Brownian motion with (1+\beta)-stable branching mechanism. It establishes the continuity of the density in dimension d=2 and the unboundedness of the density in ... More
Spatial heterogeneity in 3D-2D dimensional reductionApr 26 2006A justification of heterogeneous membrane models as zero-thickness limits of a cylindral three-dimensional heterogeneous nonlinear hyperelastic body is proposed in the spirit of Le Dret & Raoult. Specific characterizations of the 2D elastic energy are ... More
Lattice Diagram polynomials in one set of variablesMar 27 2001The space $M_{\mu/i,j}$ spanned by all partial derivatives of the lattice polynomial $\Delta_{\mu/i,j}(X;Y)$ is investigated in math.CO/9809126 and many conjectures are given. Here, we prove all these conjectures for the $Y$-free component $M_{\mu/i,j}^0$ ... More
Separating cycles and isoperimetric inequalities in the uniform infinite planar quadrangulationOct 09 2017Jun 11 2018We study geometric properties of the infinite random lattice called the uniform infinite planar quadrangulation or UIPQ. We establish a precise form of a conjecture of Krikun stating that the minimal size of a cycle that separates the ball of radius $R$ ... More
On the cohomology algebra of some classes of geometrically formal manifoldsJun 05 2006Oct 10 2008We investigate harmonic forms of geometrically formal metrics, which are defined as those having the exterior product of any two harmonic forms still harmonic. We prove that a formal Sasakian metric can exist only on a real cohomology sphere and that ... More
Spectrum of the product of Toeplitz matrices with application in probabilityDec 10 2007We study the spectrum of the product of two Toeplitz operators. Assume that the symbols of these operators are continuous and real-valued and that one of them is non-negative. We prove that the spectrum of the product of finite section Toeplitz matrices ... More
Semiclassical scattering amplitude at the maximum point of the potentialApr 12 2007Apr 13 2007We compute the scattering amplitude for Schr\"odinger operators at a critical energy level, corresponding to the maximum point of the potential. We follow the wrok of Robert and Tamura, '89, using Isozaki and Kitada's representation formula for the scattering ... More
A variational approach to some transport inequalitiesAug 30 2015Apr 26 2016We relate transport-entropy inequalities to the study of critical points of functionals defined on the space of probability measures. This approach leads in particular to a new proof of a result by Otto and Villani [43] showing that the logarithmic Sobolev ... More
Hypersurfaces with small extrinsic radius or large $λ_1$ in Euclidean spacesSep 10 2010Nov 25 2010We prove that hypersurfaces of $\R^{n+1}$ which are almost extremal for the Reilly inequality on $\lambda_1$ and have $L^p$-bounded mean curvature ($p>n$) are Hausdorff close to a sphere, have almost constant mean curvature and have a spectrum which asymptotically ... More
The Hausdorff measure of stable treesSep 29 2005We study fine properties of the so-called stable trees, which are the scaling limits of critical Galton-Watson trees conditioned to be large. In particular we derive the exact Hausdorff measure function for Aldous' continuum random tree and for its level ... More
CMB and SZ effect separation with Constrained Internal Linear CombinationsJun 29 2010The `Internal Linear Combination' (ILC) component separation method has been extensively used on the data of the WMAP space mission, to extract a single component, the CMB, from the WMAP multifrequency data. We extend the ILC approach for reconstructing ... More
Toward perfect reads: self-correction of short reads via mapping on de Bruijn graphsNov 09 2017Feb 08 2018Motivations Short-read accuracy is important for downstream analyses such as genome assembly and hybrid long-read correction. Despite much work on short-read correction, present-day correctors either do not scale well on large data sets or consider reads ... More
Counting function of characteristic values and magnetic resonancesSep 19 2011We consider the meromorphic operator-valued function 1-K(z) = 1-A(z)/z where A(z) is holomorphic on the domain D, and has values in the class of compact operators acting in a given Hilbert space. Under the assumption that A(0) is a selfadjoint operator ... More
Mean--field limit of a particle approximation of the one-dimensional parabolic--parabolic Keller-Segel model without smoothingDec 20 2017Oct 16 2018In this work, we prove the well--posedness of a singularly interacting stochastic particle system and we establish propagation of chaos result towards the one-dimensional parabolic-parabolic Keller-Segel model.
Dimensional reduction for energies with linear growth involving the bending momentNov 05 2007Apr 24 2008A $\Gamma$-convergence analysis is used to perform a 3D-2D dimension reduction of variational problems with linear growth. The adopted scaling gives rise to a nonlinear membrane model which, because of the presence of higher order external loadings inducing ... More
The roughness of stylolites: Implications of 3D high resolution topography measurementsJan 04 2005Stylolites are natural pressure-dissolution surfaces in sedimentary rocks. We present 3D high resolution measurements at laboratory scales of their complex roughness. The topography is shown to be described by a self-affine scaling invariance. At large ... More
Estimating magnetic filling factors from Zeeman-Doppler magnetogramsMar 13 2019Low-mass stars are known to have magnetic fields that are believed to be of dynamo origin. Two complementary techniques are principally used to characterise them. Zeeman-Doppler imaging (ZDI) can determine the geometry of the large-scale magnetic field ... More
ABC likelihood-freee methods for model choice in Gibbs random fieldsJul 17 2008Apr 03 2009Gibbs random fields (GRF) are polymorphous statistical models that can be used to analyse different types of dependence, in particular for spatially correlated data. However, when those models are faced with the challenge of selecting a dependence structure ... More
Barrier-top resonances for non globally analytic potentialsOct 20 2016We give the semiclassical asymptotic of barrier-top resonances for Schr\"{o}dinger operators on ${\mathbb R}^{n}$, $n \geq 1$, whose potential is $C^{\infty}$ everywhere and analytic at infinity. In the globally analytic setting, this has already been ... More
Propagation des singularités et résonancesApr 12 2017In the framework of semiclassical resonances, we make more precise the link between polynomial estimates of the extension of the resolvent and propagation of the singularities through the trapped set. This approach makes it possible to eliminate infinity ... More
Signal Processing for Pico-second Resolution Timing MeasurementsOct 30 2008The development of large-area homogeneous photo-detectors with sub-millimeter path lengths for direct Cherenkov light and for secondary-electrons opens the possibility of large time-of-flight systems for relativistic particles with resolutions in the ... More
Velocity profiles in shear-banding wormlike micellesNov 21 2002Using Dynamic Light Scattering in heterodyne mode, we measure velocity profiles in a much studied system of wormlike micelles (CPCl/NaSal) known to exhibit both shear-banding and stress plateau behavior. Our data provide evidence for the simplest shear-banding ... More
Gravitational Waves from Abelian Gauge Fields and Cosmic Strings at PreheatingJun 01 2010Sep 23 2010Primordial gravitational waves provide a very important stochastic background that could be detected soon with interferometric gravitational wave antennas or indirectly via the induced patterns in the polarization anisotropies of the cosmic microwave ... More
Thermal photon anisotropic flow serves as a quark-gluon plasma viscometerMar 28 2014Photons are a penetrating probe of the hot and dense medium created in heavy-ion collisions. We present state-of-the-art calculations of viscous photon emission from nuclear collisions at RHIC and LHC. Thermal photons anisotropic flow coefficients v_n ... More
Automated Model Selection with Bayesian QuadratureFeb 26 2019Feb 28 2019We present a novel technique for tailoring Bayesian quadrature (BQ) to model selection. The state-of-the-art for comparing the evidence of multiple models relies on Monte Carlo methods, which converge slowly and are unreliable for computationally expensive ... More
Complex-temperature phase diagram of Potts and RSOS modelsNov 02 2005Feb 17 2006We study the phase diagram of Q-state Potts models, for Q=4 cos^2(PI/p) a Beraha number (p>2 integer), in the complex-temperature plane. The models are defined on L x N strips of the square or triangular lattice, with boundary conditions on the Potts ... More
Selfduality for coupled Potts models on the triangular latticeFeb 16 2004We present selfdual manifolds for coupled Potts models on the triangular lattice. We exploit two different techniques: duality followed by decimation, and mapping to a related loop model. The latter technique is found to be superior, and it allows to ... More
Maximal velocity of photons in non-relativistic QEDOct 18 2011We consider the problem of propagation of photons in the quantum theory of non-relativistic matter coupled to electromagnetic radiation, which is, presently, the only consistent quantum theory of matter and radiation. Assuming that the matter system is ... More
Predictive Control of a Permanent Magnet Synchronous Machine based on Real-Time Dynamic OptimizationDec 01 2012A predictive control scheme for a permanent-magnet synchronous machine (PMSM) is presented. It is based on a suboptimal method for computationally efficient trajectory generation based on continuous parameterization and linear programming. The torque ... More
Identifying combinations of tetrahedra into hexahedra: a vertex based strategyMay 06 2017Jan 04 2018Indirect hex-dominant meshing methods rely on the detection of adjacent tetrahedra an algorithm that performs this identification and builds the set of all possible combinations of tetrahedral elements of an input mesh T into hexahedra, prisms, or pyramids. ... More
Probing fragmentation functions from same-side hadron-jet momentum correlations in p-p collisionsNov 28 2013A next-to-leading order (NLO) analysis of hadron-jet momentum correlations in p-p collisions at the LHC is carried out. We show that the inclusive charged hadron momentum distributions inside jets is a very sensitive observable which allows one to disentangle ... More
On the accurate computation of the true contact-area in mechanical contact of random rough surfacesDec 31 2016We introduce a corrective function to compensate errors in contact area computations coming from mesh discretization. The correction is based on geometrical arguments and requires only one additional quantity to be computed: the length of contact/non-contact ... More
Gaussian Process Forecast with multidimensional distributional entriesMay 02 2018In this work, we propose to define Gaussian Processes indexed by multidimensional distributions. In the framework where the distributions can be modeled as i.i.d realizations of a measure on the set of distributions, we prove that the kernel defined as ... More
The Neumann sieve problem and dimensional reduction: a multiscale approachMay 30 2006We perform a multiscale analysis for the elastic energy of a $n$-dimensional bilayer thin film of thickness $2\delta$ whose layers are connected through an $\epsilon$-periodically distributed contact zone. Describing the contact zone as a union of $(n-1)$-dimensional ... More
Linear response theory for magnetic Schroedinger operators in disordered mediaAug 18 2004Jan 21 2005We justify the linear response theory for an ergodic Schroedinger operator with magnetic field within the non-interacting particle approximation, and derive a Kubo formula for the electric conductivity tensor. To achieve that, we construct suitable normed ... More
Modelling stellar coronal magnetic fieldsAug 28 2010Our understanding of the structure and dynamics of stellar coronae has changed dramatically with the availability of surface maps of both star spots and also magnetic field vectors. Magnetic field extrapolations from these surface maps reveal surprising ... More
Direct magnetic field detection in the innermost regions of an accretion discNov 24 2005Models predict that magnetic fields play a crucial role in the physics of astrophysical accretion disks and their associated winds and jets. For example, the rotation of the disk twists around the rotation axis the initially vertical magnetic field, which ... More
Magnetohydrostatic modelling of stellar coronaeNov 19 2015We introduce to the stellar physics community a method of modelling stellar coronae that can be considered to be an extension of the potential field. In this approach, the magnetic field is coupled to the background atmosphere. The model is magnetohydrostatic ... More
Study of Short Bunches at the Free Electron Laser CLIOApr 28 2016May 05 2016CLIO is a Free Electron Laser based on a thermionic electron gun. In its normal operating mode it delivers electron 8 pulses but studies are ongoing to shorten the pulses to about 1 ps. We report on simulations showing how the pulse can be shortened and ... More
CP violation in the B0s systemJun 28 2007Jul 06 2007In this paper the most recent Tevatron results concerning CP violation in the B0s system are reviewed. These are the measurement of the direct CP asymmetry in the B0s->K-\pi+ decay performed by CDF and the measurement of \Delta\Gamma_s and \phi_s performed ... More
A small survey of the magnetic fields of planet-host starsJul 23 2013Jul 24 2013Using spectropolarimetry, we investigate the large-scale magnetic topologies of stars hosting close-in exoplanets. A small survey of ten stars has been done with the twin instruments TBL/NARVAL and CFHT/ESPaDOnS between 2006 and 2011. Each target consists ... More
Modelling the Corona of HD 189733 in 3DNov 10 2014The braking of main sequence stars originates mainly from their stellar wind. The efficiency of this angular momentum extraction depends on the rotation rate of the star, the acceleration profile of the wind and the coronal magnetic field. The derivation ... More
In-situ diagnostics of the crystalline nature of single organic nanocrystals by nonlinear microscopySep 02 2003We elucidate the crystalline nature and the three-dimensional orientation of isolated organic nanocrystals embedded in a sol-gel matrix, using a polarized nonlinear microscopy technique that combines two-photon fluorescence and second harmonic generation. ... More
Laboratory verification of 'Fast & Furious' phase diversity: Towards controlling the low wind effect in the SPHERE instrumentMar 08 2018The low wind effect (LWE) refers to a characteristic set of quasi-static wavefront aberrations seen consistently by the SPHERE instrument when dome-level wind speeds drop below 3 m/s. This effect produces bright low-order speckles in the stellar PSF, ... More
Event-by-event direct photon anisotropic flow in relativistic heavy-ion collisionsJul 31 2014We consider directly emitted and hadronic decay photons from event-by-event hydrodynamic simulations. We compute the direct photon anisotropic flow coefficients and compare with recent experimental measurements. We find that it is crucial to include the ... More
A Radio-Frequency-over-Fiber link for large-array radio astronomy applicationsAug 26 2013Oct 02 2013A prototype 425-850 MHz Radio-Frequency-over-Fiber (RFoF) link for the Canadian Hydrogen Intensity Mapping Experiment (CHIME) is presented. The design is based on a directly modulated Fabry-Perot (FP) laser, operating at ambient temperature, and a single-mode ... More
Large spheres motion in a non homogeneous turbulent flowSep 09 2013We investigate the dynamics of very large particles freely advected in a turbulent von Karman flow. Contrary to other experiments for which the particle dynamics is generally studied near the geometrical center of the flow, we track the particles in the ... More
Asymmetric EPR entanglement in continuous variable systemsMar 09 2012Continuous variable entanglement can be produced in nonlinear systems or via interference of squeezed states. In many of optical systems, such as parametric down conversion or interference of optical squeezed states, production of two perfectly symmetric ... More
A Generic and Extensible Framework for Monitoring Energy Consumption of OpenStack CloudsAug 27 2014Although cloud computing has been transformational to the IT industry, it is built on large data centres that often consume massive amounts of electrical power. Efforts have been made to reduce the energy clouds consume, with certain data centres now ... More
Modeling Representation of Minorities Under Multiwinner Voting RulesApr 08 2016The goal of this paper is twofold. First and foremost, we aim to experimentally and quantitatively show that the choice of a multiwinner voting rule can play a crucial role on the way minorities are represented. We also test the possibility for some of ... More
Radio Astrometry Of The Triple Systems Algol And UX ArietisApr 26 2011We have used multi-epoch long-baseline radio interferometry to determine the proper motion and orbital elements of Algol and UX Arietis, two radio-bright, close binary stellar systems with distant tertiary components. For Algol, we refine the proper motion ... More
A peculiar galaxy appears at redshift 11: properties of a moderate redshift interloperMay 30 2012Laporte et al. (2011) reported a very high redshift galaxy candidate: a lensed J-band dropout (A2667-J1). J1 has a photometric redshift of z=9.6-12, the probability density function for which permits no low or intermediate z solution. We here report new ... More
Phase Behavior of Polyelectrolyte Block Copolymers in Mixed SolventsJan 25 2008We have studied the phase behavior of the poly(n-butyl acrylate)-b-poly(acrylic acid) block copolymer in a mixture of two miscible solvents, water and tetrahydrofuran (THF). The techniques used to examine the different polymers, structures and phases ... More
Asynchronous Neighbor Discovery Using Coupled Compressive SensingNov 02 2018The neighbor discovery paradigm finds wide application in Internet of Things networks, where the number of active devices is orders of magnitude smaller than the total device population. Designing low-complexity schemes for asynchronous neighbor discovery ... More
Revisiting Matrix Product on Master-Worker PlatformsDec 06 2006This paper is aimed at designing efficient parallel matrix-product algorithms for heterogeneous master-worker platforms. While matrix-product is well-understood for homogeneous 2D-arrays of processors (e.g., Cannon algorithm and ScaLAPACK outer product ... More
Probing the early-time dynamics of relativistic heavy-ion collisions with electromagnetic radiationApr 14 2014Aug 07 2014Using 3+1D viscous relativistic fluid dynamics, we show that electromagnetic probes are sensitive to the initial conditions and to the out-of-equilibrium features of relativistic heavy-ion collisions. Within the same approach, we find that hadronic observables ... More