Results for "Elodie Choquet"

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Posterior consistency for nonparametric hidden Markov models with finite state spaceNov 13 2013Jul 08 2014In this paper we study posterior consistency for different topologies on the parameters for hidden Markov models with finite state space. We first obtain weak and strong posterior consistency for the marginal density function of finitely many consecutive ... More
Non Parametric Hidden Markov Models with Finite State Space: Posterior Concentration RatesNov 27 2015The use of non parametric hidden Markov models with finite state space is flourishing in practice while few theoretical guarantees are known in this framework. Here, we study asymptotic guarantees for these models in the Bayesian framework. We obtain ... More
A new proof of Delsarte, Goethals and Mac Williams theorem on minimal weight codewords of generalized Reed-Muller codeJan 14 2010We give a new proof of Delsarte, Goethals and Mac williams theorem on minimal weight codewords of generalized Reed-Muller codes published in 1970. To prove this theorem, we consider intersection of support of minimal weight codewords with affine hyperplanes ... More
Pushing the Limits of Exoplanet Discovery via Direct Imaging with Deep LearningApr 12 2019Further advances in exoplanet detection and characterisation require sampling a diverse population of extrasolar planets. One technique to detect these distant worlds is through the direct detection of their thermal emission. The so-called direct imaging ... More
High-contrast imager for Complex Aperture Telescopes (HiCAT): 2. Design overview and first light resultsJul 03 2014We present a new high-contrast imaging testbed designed to provide complete solutions in wavefront sensing, control and starlight suppression with complex aperture telescopes. The testbed was designed to enable a wide range of studies of the effects of ... More
James Webb Space Telescope Optical Simulation Testbed V: Wide-field phase retrieval assessmentOct 15 2018The James Webb Space Telescope (JWST) Optical Simulation Testbed (JOST) is a hardware simulator for wavefront sensing and control designed to produce JWST-like images. A model of the JWST three mirror anas- tigmat is realized with three lenses in the ... More
Reference star differential imaging of close-in companions and circumstellar disks with the NIRC2 vortex coronagraph at W.M. Keck ObservatoryJan 13 2019Jan 15 2019Reference star differential imaging (RDI) is a powerful strategy for high contrast imaging. Using example observations taken with the vortex coronagraph mode of Keck/NIRC2 in $L^\prime$ band, we demonstrate that RDI provides improved sensitivity to point ... More
The SHARDDS survey: first resolved image of the HD114082 debris disk in Lower Centaurus Crux with SPHERENov 17 2016We present the first resolved image of the debris disk around the 16+/-8 Myr old star, HD 114082. The observation was made in the H-band using the SPHERE instrument. The star is at a distance of 92+/-6 pc in the Lower Centaurus Crux association. Using ... More
Study of a finite volume - finite element scheme for a nuclear transport modelApr 10 2007We consider a problem of nuclear waste contamination. It takes into account the thermal effects. The temperature and the contaminant's concentration fulfill convection-diffusion-reaction equations. The velocity and the pressure in the flow satisfy the ... More
An Integrated Framework for Diagnosis and Prognosis of Hybrid SystemsAug 24 2013Complex systems are naturally hybrid: their dynamic behavior is both continuous and discrete. For these systems, maintenance and repair are an increasing part of the total cost of final product. Efficient diagnosis and prognosis techniques have to be ... More
Cumulative distribution function estimation under interval censoring case 1Mar 18 2008Jan 29 2009We consider projection methods for the estimation of the cumulative distribution function under interval censoring, case 1. Such censored data also known as current status data, arise when the only information available on the variable of interest is ... More
MAMBO image of the debris disk around epsilon Eridani : robustness of the azimuthal structureMar 10 2015The debris disk closest to Earth is the one around the star epsilon Eridani at a distance of 3.2 pc. It is the prime target for detailed studies of a belt of planetesimals left from the early phase of planet formation other than the Kuiper Belt. The non-uniform ... More
Non linear stability of einsteinian spacetimes with U(1) isometry groupFeb 07 2003We prove global completeness in the expanding direction of spacetimes satisfying the vacuum Einstein equations on a manifold of the form $\Sigma \times S^{1}\times R$ where $\Sigma $ is a compact surface of genus $G>1.$ The Cauchy data are supposed to ... More
Half polarized U(1) symmetric vacuum spacetimes with AVTD behaviorJun 10 2005In a previous work, we used a polarization condition to show that there is a family of U(1) symmetric solutions of the vacuum Einstein equations such that each exhibits AVTD (Asymptotic Velocity Term Dominated) behavior in the neighborhood of its singularity. ... More
Motion of Isolated bodiesMay 17 2006It is shown that sufficiently smooth initial data for the Einstein-dust or the Einstein-Maxwell-dust equations with non-negative density of compact support develop into solutions representing isolated bodies in the sense that the matter field has spatially ... More
Lessons for WFIRST CGI from ground-based high-contrast systemsJan 13 2019The Coronagraph Instrument (CGI) for NASA's Wide Field Infrared Survey Telescope (WFIRST) will constitute a dramatic step forward for high-contrast imaging, integral field spectroscopy, and polarimetry of exoplanets and circumstellar disks, aiming to ... More
Future Global in time einsteinian spacetimes with U(1) isometry groupDec 19 2001We prove that spacetimes satisfying the vacuum Einstein equations on a manifold of the form $\Sigma \times U(1)\times R$ where $\Sigma $ is a compact surface of genus $G>1$ and where the Cauchy data is invariant with respect to U(1) and sufficiently small ... More
Discovery of a low-mass companion inside the debris ring surrounding the F5V star HD206893Dec 01 2016Dec 06 2016Uncovering the ingredients and the architecture of planetary systems is a very active field of research that has fuelled many new theories on giant planet formation, migration, composition, and interaction with the circumstellar environment. We aim at ... More
Global Hyperbolicity and CompletenessJan 17 2002Jan 21 2002We prove global hyperbolicity of spacetimes under generic regularity conditions on the metric. We then show that these spacetimes are timelike and null geodesically complete if the gradient of the lapse and the extrinsic curvature $K$ are integrable. ... More
Lower bounds for the dyadic Hilbert transformMay 18 2016May 21 2016In this paper, we seek lower bounds of the dyadic Hilbert transform (Haar shift) of the form $\Vert f\Vert_{L^2(K)} \ge C(I, K)\Vert f\Vert_{L^2(I)}$ where $I$ and $K$ are two dyadic intervals and $f$ is supported in $I$. If $I \subset K$ such bounds ... More
Machine Assisted Analysis of Vowel Length Contrasts in WolofJun 01 2017Growing digital archives and improving algorithms for automatic analysis of text and speech create new research opportunities for fundamental research in phonetics. Such empirical approaches allow statistical evaluation of a much larger set of hypothesis ... More
A Bayesian nonparametric approach for generalized Bradley-Terry models in random environmentAug 24 2018This paper deals with the estimation of the unknown distribution of hidden random variables from the observation of pairwise comparisons between these variables. This problem is inspired by recent developments on Bradley-Terry models in random environment ... More
Approximation of Riemannian Distances and Applications to Distance-Based Learning on ManifoldsApr 26 2019Several important algorithms for machine learning and data analysis use pairwise distances as input. On Riemannian manifolds these distances may be prohibitively costly to compute, in particular for large datasets. To tackle this problem, we propose a ... More
The constraint equations for the Einstein-scalar field system on compact manifoldsOct 10 2006Dec 11 2006We study the constraint equations for the Einstein-scalar field system on compact manifolds. Using the conformal method we reformulate these equations as a determined system of nonlinear partial differential equations. By introducing a new conformal invariant, ... More
Cauchy problem with data on a characteristic cone for the Einstein-Vlasov equationsJun 02 2012We show how to solve the Cauchy problem for the Einstein-Vlasov equations with geometric initial data on a light-cone.
Einstein Bianchi equations with sourcesNov 07 2005In this article, dedicated to one of the best specialist of the FOSH systems, we couple the Bianchi equations with the equations satisfied by the dynamical acceleration of a charged fluid and the derivatives of the associated Maxwell field.
Applications of theorems of Jean Leray to the Einstein-scalar field equationsNov 02 2006The Einstein-scalar field theory can be used to model gravitational physics with scalar field matter sources. We discuss the initial value formulation of this field theory, and show that the ideas of Leray can be used to show that the Einstein-scalar ... More
The Einstein-scalar field constraints on asymptotically Euclidean manifoldsJun 20 2005We use the conformal method to obtain solutions of the Einstein-scalar field gravitational constraint equations. Handling scalar fields is a bit more challenging than handling matter fields such as fluids, Maxwell fields or Yang-Mills fields, because ... More
WFIRST-AFTA Coronagraphic Operations: Lessons Learned from the Hubble Space Telescope and the James Webb Space TelescopeNov 19 2015The coronagraphic instrument currently proposed for the WFIRST-AFTA mission will be the first example of a space-based coronagraph optimized for extremely high contrasts that are required for the direct imaging of exoplanets reflecting the light of their ... More
New constraints on the dust surrounding HR 4796AJul 09 2014Feb 24 2015HR 4796A is surrounded by a well-structured and very bright circumstellar disc shaped like an annulus with many interesting features: very sharp inner and outer edges, brightness asymmetries, centre offset, and suspected distortions in the ring. We aim ... More
Mixed Elliptic and Hyperbolic Systems for the Einstein EquationsJan 20 1996We analyse the mathematical underpinnings of a mixed hyperbolic-elliptic form of the Einstein equations of motion in which the lapse function is determined by specified mean curvature and the shift is arbitrary. We also examine a new recently-published ... More
Topologically general U(1) symmetric Einstein spacetimes with AVTD behaviorFeb 24 2005We use Fuchsian methods to show that, for any two dimensional manifold $\Sigma^2$, there is a large family of U(1) symmetric solutions of the vacuum Einstein equations on the manifold $\Sigma \times S^1 \times \mathbb{R}$, each of which has AVTD behavior ... More
Efficient semiparametric estimation and model selection for multidimensional mixturesJul 19 2016Dec 13 2017In this paper, we consider nonparametric multidimensional finite mixture models and we are interested in the semiparametric estimation of the population weights. Here, the i.i.d. observations are assumed to have at least three components which are independent ... More
Non-asymptotic Adaptive Prediction in Functional Linear ModelsJan 14 2013Functional linear regression has recently attracted considerable interest. Many works focus on asymptotic inference. In this paper we consider in a non asymptotic framework a simple estimation procedure based on functional Principal Regression. It revolves ... More
Characterizing the Atmospheres of the HR8799 Planets with HST/WFC3Aug 10 2015We present results from a Hubble Space Telescope (HST) program characterizing the atmospheres of the outer two planets, in the HR8799 system. The images were taken over 15 orbits in three near-infrared medium-band filters - F098M, F127M and F139M - using ... More
Bianchi - Euler system for relativistice fluids and Bel - Robinson type energyJun 29 2002We write a first order symmetric hyperbolic system coupling the Riemann with the dynamical acceleration of a relativistic fluid. W determine the associated, coupled, Bel - Robinson energy, and the integral equality that it satisfies.
Convergence to the Reynolds approximation with a double effect of roughnessFeb 17 2010We prove that the lubrication approximation is perturbed by a non-regular roughness of the boundary. We show how the flow may be accelerated using adequate rugosity profiles on the bottom. We explicit the possible effects of some abrupt changes in the ... More
Efficient semiparametric estimation and model selection for multidimensional mixturesJul 19 2016In this paper, we consider nonparametric multidimensional finite mixture models and we are interested in the semiparametric estimation of the population weights. Here, the i.i.d. observations are assumed to have at least three components which are independent ... More
Lower bounds for the dyadic Hilbert transformMay 18 2016Nov 28 2016In this paper, we seek lower bounds of the dyadic Hilbert transform (Haar shift) of the form $\left\Vert S f\right\Vert_{L^2(K)}\geq C(I,K)\left\Vert f\right\Vert_{L^2(I)}$ where $I$ and $K$ are two dyadic intervals and $f$ supported in $I$. If $I\subset ... More
Cryomagma ascent on EuropaApr 03 2018Aug 28 2018Europa's surface exhibits morphological features which, associated with a low crater density demonstrate a recent cryovolcanic activity. In particular, the morphology of the smooth plains covering parts of the surface, and their relationship to the surrounding ... More
Well Posed Reduced Systems for the Einstein EquationsJun 03 1996We review some well posed formulations of the evolution part of the Cauchy problem of General Relativity that we have recently obtained. We include also a new first order symmetric hyperbolic system based directly on the Riemann tensor and the full Bianchi ... More
Geometrical Well Posed Systems for the Einstein EquationsJun 28 1995We show that, given an arbitrary shift, the lapse $N$ can be chosen so that the extrinsic curvature $K$ of the space slices with metric $\overline g$ in arbitrary coordinates of a solution of Einstein's equations satisfies a quasi-linear wave equation. ... More
On H. Friedrich's formulation of Einstein'equations with fluid sourcesFeb 05 2002We establish a variant, which has the advantage of introducing only physical characteristics, of the symmetric quasi linear first order system given by H.\ Friedrich for the evolution equations of gravitating fluid bodies in General Relativity which can ... More
Constraints and evolution in cosmologyFeb 05 2002We review some old and new results about strict and non strict hyperbolic formulations of the Einstein equations.
A Quenched Functional Central Limit Theorem for Random Walks in Random Environments under $(T)_γ$Sep 19 2014We prove a quenched central limit theorem for random walks in i.i.d. weakly elliptic random environments in the ballistic regime. Such theorems have been proved recently by Rassoul-Agha and Sepp\"al\"ainen in [10] and Berger and Zeitouni in [2] under ... More
Population synthesis modelling of luminous infrared galaxies at intermediate redshiftJun 29 2010Jul 27 2010Luminous InfraRed Galaxies (LIRGs) are particularly important for studying the build-up of the stellar mass from z=1 to z=0. We perform a multiwavelength study of an LIRGs sample in the Extended Chandra Deep Field South at z=0.7, selected at 24 \mu\m ... More
Fragmentation and Limits to Dynamical Scaling in Viscous Coarsening: An Interrupted in situ X-Ray Tomographic StudySep 06 2013Sep 04 2014X-Ray microtomography was used to follow the coarsening of the structure of a ternary silicate glass experiencing phase separation in the liquid state. The volumes, surfaces, mean and Gaussian curvatures of the domains of minority phase were measured ... More
Observing Exoplanets with High-Dispersion Coronagraphy. II. Demonstration of an Active Single-Mode Fiber Injection UnitMar 02 2017High-dispersion coronagraphy (HDC) optimally combines high contrast imaging techniques such as adaptive optics/wavefront control plus coronagraphy to high spectral resolution spectroscopy. HDC is a critical pathway towards fully characterizing exoplanet ... More
High-contrast imager for Complex Aperture Telescopes (HiCAT): 1. Testbed designJul 03 2014Searching for nearby habitable worlds with direct imaging and spectroscopy will require a telescope large enough to provide angular resolution and sensitivity to planets around a significant sample of stars. Segmented telescopes are a compelling option ... More
Curvature-based Hyperbolic Systems for General RelativityFeb 12 1998Feb 26 1998We review curvature-based hyperbolic forms of the evolution part of the Cauchy problem of General Relativity that we have obtained recently. We emphasize first order symmetrizable hyperbolic systems possessing only physical characteristics.
Einstein constraints on a characteristic coneFeb 07 2010We analyse the Cauchy problem on a characteristic cone, including its vertex, for the Einstein equations in arbitrary dimensions. We use a wave map gauge, solve the obtained constraints and show gauge conservation.
The light-cone theoremMay 13 2009Jun 11 2009We prove that the area of cross-sections of light-cones, in space-times satisfying suitable energy conditions, is smaller than or equal to that of the corresponding cross-sections in Minkowski, or de Sitter, or anti-de Sitter space-time. The equality ... More
Einstein's Equations and Equivalent Hyperbolic Dynamical SystemsJul 28 1999Aug 06 1999We discuss several explicitly causal hyperbolic formulations of Einstein's dynamical 3+1 equations in a coherent way, emphasizing throughout the fundamental role of the ``slicing function,'' $\alpha$---the quantity that relates the lapse $N$ to the determinant ... More
Einstein Constraints on Asymptotically Euclidean ManifoldsJun 23 1999Jul 06 1999We consider the Einstein constraints on asymptotically euclidean manifolds $M$ of dimension $n \geq 3$ with sources of both scaled and unscaled types. We extend to asymptotically euclidean manifolds the constructive method of proof of existence. We also ... More
An existence theorem for the Cauchy problem on the light-cone for the vacuum Einstein equations with near-round analytic dataDec 03 2010We prove that analytic initial data on a light cone arising from a metric satisfying a "near-roundness" condition near the vertex lead to a solution of the vacuum Einstein equations to the future of the light-cone.
The Cauchy problem on a characteristic cone for the Einstein equations in arbitrary dimensionsJun 23 2010We derive explicit formulae for a set of constraints for the Einstein equations on a null hypersurface, in arbitrary dimensions. We solve these constraints and show that they provide necessary and sufficient conditions so that a spacetime solution of ... More
Composition operators on generalized Hardy spacesOct 16 2013Let $\Omega_1,\Omega_2\subset {\mathbb C}$ be bounded domains. Let $\phi:\Omega_1\rightarrow \Omega_2$ holomorphic in $\Omega_1$ and belonging to $W^{1,\infty}_{\Omega_2}(\Omega_1)$. We study the composition operators $f\mapsto f\circ\phi$ on generalized ... More
Biodegradation of 2-ethylhexyl nitrate (2-EHN) by Mycobacterium austroafricanum IFP 2173Apr 23 20092-Ethyhexyl nitrate (2-EHN) is a major additive of fuel which is used to comply with the cetane number of diesel. Because of its wide use and possible accidental release, 2-EHN is a potential pollutant of the environment. In this study, Mycobacterium ... More
Einstein-Bianchi Hyperbolic System for General RelativityOct 07 1997Feb 26 1998By employing the Bianchi identities for the Riemann tensor in conjunction with the Einstein equations, we construct a first order symmetric hyperbolic system for the evolution part of the Cauchy problem of general relativity. In this system, the metric ... More
Kalman-filter control schemes for fringe tracking. Development and application to VLTI/GRAVITYMar 20 2012The implementation of fringe tracking for optical interferometers is inevitable when optimal exploitation of the instrumental capacities is desired. Fringe tracking allows continuous fringe observation, considerably increasing the sensitivity of the interferometric ... More
Global solutions of the Einstein-Maxwell equations in higher dimensionsAug 24 2006Nov 01 2006We consider the Einstein-Maxwell equations in space-dimension $n$. We point out that the Lindblad-Rodnianski stability proof applies to those equations whatever the space-dimension $n\ge 3$. In even space-time dimension $n+1\ge 6$ we use the standard ... More
An existence theorem for the Cauchy problem on a characteristic cone for the Einstein equationsJun 29 2010We prove an existence theorem for the Cauchy problem on a characteristic cone for the vacuum Einstein equations.
Modelling of shallow aquifers in interaction with overland waterMar 16 2019In this work, we present a class of new efficient models for water flow in shallow unconfined aquifers, giving an alternative to the classical but less tractable 3D-Richards model. Its derivation is guided by two ambitions: any new model should be low ... More
Mapping charge transport effects in thick CCDs with a dithered array of 40,000 starsJul 09 2015We characterize the astrometric distortion at the edges of thick, fully-depleted CCDs in the lab using a bench-top simulation of LSST observing. By illuminating an array of forty thousand pinholes (30mu m diameter) at the object plane of a f/1.2 optical ... More
Calculated spectra for HeH+ and its effect on the opacity of cool metal poor starsNov 10 2004The wavelength and Einstein A coefficient are calculated for all rotation-vibration transitions of $^4$He$^1$H$^+$, $^3$He$^1$H$^+$, $^4$He$^2$H$^+$ and $^3$He$^2$H$^+$, giving a complete line list and the partition function for $^4$HeH$^+$ and its isotopologues. ... More
Lithiation of silicon via lithium Zintl-defect complexesMay 27 2013An extensive search for low-energy lithium defects in crystalline silicon using density-functional-theory methods and the ab initio random structure searching (AIRSS) method shows that the four-lithium-atom substitutional point defect is exceptionally ... More
Universal behaviour of a wave chaos based electromagnetic reverberation chamberAug 09 2013In this article, we present a numerical investigation of three-dimensional electromagnetic Sinai-like cavities. We computed around 600 eigenmodes for two different geometries: a parallelepipedic cavity with one half- sphere on one wall and a parallelepipedic ... More
Solutions to inverse moment estimation problems in dimension 2, using best constrained approximationMar 27 2019We study an inverse problem that consists in estimating the first (zero-order) moment of some R2-valued distribution m supported within a closed interval S $\subset$ R, from partial knowledge of the solution to the Poisson-Laplace partial differential ... More
CIGALEMC: Galaxy Parameter Estimation using a Markov Chain Monte Carlo Approach with CigaleMar 16 2011Jul 19 2011We introduce a fast Markov Chain Monte Carlo (MCMC) exploration of the astrophysical parameter space using a modified version of the publicly available code CIGALE (Code Investigating GALaxy emission). The original CIGALE builds a grid of theoretical ... More
Improved brain pattern recovery through ranking approachesJul 15 2012Inferring the functional specificity of brain regions from functional Magnetic Resonance Images (fMRI) data is a challenging statistical problem. While the General Linear Model (GLM) remains the standard approach for brain mapping, supervised learning ... More
Elastometry of Deflated Capsules: Elastic Moduli from Shape and Wrinkle AnalysisSep 12 2013Elastic capsules, prepared from droplets or bubbles attached to a capillary (as in a pendant drop tensiometer), can be deflated by suction through the capillary. We study this deflation and show that a combined analysis of the shape and wrinkling characteristics ... More
Applying Active Diagnosis to Space Systems by On-Board Control ProceduresMar 05 2019The instrumentation of real systems is often designed for control purposes and control inputs are designed to achieve nominal control objectives. Hence, the available measurements may not be sufficient to isolate faults with certainty and diagnoses are ... More
Learning to rank from medical imaging dataJul 16 2012Sep 30 2012Medical images can be used to predict a clinical score coding for the severity of a disease, a pain level or the complexity of a cognitive task. In all these cases, the predicted variable has a natural order. While a standard classifier discards this ... More
High-contrast imager for complex aperture telescopes (HiCAT): 5. first results with segmented-aperture coronagraph and wavefront controlMar 13 2019Segmented telescopes are a possibility to enable large-aperture space telescopes for the direct imaging and spectroscopy of habitable worlds. However, the complexity of their aperture geometry, due to the central obstruction, support structures and segment ... More
Hyperbolic Formulation of General RelativityMar 04 1997Two geometrical well-posed hyperbolic formulations of general relativity are described. One admits any time-slicing which preserves a generalized harmonic condition. The other admits arbitrary time-slicings. Both systems have only the physical characteristic ... More
A non-strictly hyperbolic system for the Einstein equations with arbitrary lapse and shiftJul 03 1996We obtain a system for the spatial metric and extrinsic curvature of a spacelike slice that is hyperbolic non-strict in the sense of Leray and Ohya and is equivalent to the Einstein equations. Its characteristics are the light cone and the normal to the ... More
Geometrical Hyperbolic Systems for General Relativity and Gauge TheoriesMay 08 1996The evolution equations of Einstein's theory and of Maxwell's theory---the latter used as a simple model to illustrate the former--- are written in gauge covariant first order symmetric hyperbolic form with only physically natural characteristic directions ... More
James Webb Space Telescope Optical Simulation Testbed II. Design of a Three-Lens Anastigmat Telescope SimulatorJun 29 2014The James Webb Space Telescope (JWST) Optical Simulation Testbed (JOST) is a tabletop experiment designed to reproduce the main aspects of wavefront sensing and control (WFSC) for JWST. To replicate the key optical physics of JWST's three-mirror anastigmat ... More
The evolving relation between star-formation rate and stellar mass in the VIDEO Survey since $z=3$Jul 27 2015We investigate the star-formation rate (SFR) and stellar mass ($M_*$) relation of a star-forming (SF) galaxy sample in the XMM-LSS field to $z\sim 3.0$ using the near-infrared data from the VISTA Deep Extragalactic Observations (VIDEO) survey. Combining ... More
Einstein and Yang-Mills theories in hyperbolic form without gauge-fixingJun 28 1995The evolution of physical and gauge degrees of freedom in the Einstein and Yang-Mills theories are separated in a gauge-invariant manner. We show that the equations of motion of these theories can always be written in flux-conservative first-order symmetric ... More
Single metallic nanoparticle imaging for protein detection in cellsApr 28 2007We performed a visualization of membrane proteins labeled with 10-nm gold nanoparticles in cells, using an all-optical method based on photothermal interference contrast. The high sensitivity of the method and the stability of the signals allows 3D imaging ... More
Post-processing of the HST STIS coronagraphic observationsSep 28 2017In the past 20 years, the Hubble Space Telescope (HST) STIS coronagraphic instrument has observed more than 100 stars, obtaining more than 4,000 readouts since its installment on HST in 1997 and the numbers are still increasing. We reduce the whole STIS ... More
A Bayesian approach for energy-based estimation of acoustic aberrations in high intensity focused ultrasound treatmentFeb 24 2016High intensity focused ultrasound is a non-invasive method for treatment of diseased tissue that uses a beam of ultrasound in order to generate heat within a small volume. A common challenge in application of this technique is that heterogeneity of the ... More
A Bayesian approach for energy-based estimation of acoustic aberrations in high intensity focused ultrasound treatmentFeb 24 2016Jun 07 2018High intensity focused ultrasound is a non-invasive method for treatment of diseased tissue that uses a beam of ultrasound to generate heat within a small volume. A common challenge in application of this technique is that heterogeneity of the biological ... More
Comparison of fringe-tracking algorithms for single-mode near-infrared long-baseline interferometersJun 17 2014Jun 28 2014To enable optical long baseline interferometry toward faint objects, long integrations are necessary despite atmospheric turbulence. Fringe trackers are needed to stabilize the fringes and thus increase the fringe visibility and phase signal-to-noise ... More
Active optics for high-dynamic variable curvature mirrorsNov 18 2014Variable curvature mirrors of large amplitude are designed by using finite element analysis. The specific case studied reaches at least a 800 {\mu}m sag with an optical quality better than {\lambda}/5 over a 120 mm clear aperture. We highlight the geometrical ... More
Near-field to far-field characterization of speckle patterns generated by disordered nanomaterialsJan 07 2016We study the intensity spatial correlation function of optical speckle patterns above a disordered dielectric medium in the multiple scattering regime. The intensity distributions are recorded by scanning near-field optical microscopy (SNOM) with sub-wavelength ... More
Discovery of a low-mass companion inside the debris ring surrounding the F5V star HD206893Dec 01 2016Uncovering the ingredients and the architecture of planetary systems is a very active field of research that has fuelled many new theories on giant planet formation, migration, composition, and interaction with the circumstellar environment. We aim at ... More
Hydrodynamic coarsening in phase-separated silicate meltsFeb 12 2015Using in-situ synchrotron tomography, we investigate the coarsening dynamics of barium borosilicate melts during phase separation. The 3-D geometry of the two interconnected phases is determined thanks to image processing. We observe a linear growth of ... More
Comprehensive analysis of HD 105, a young Solar System analogNov 15 2018HD~105 is a nearby, pre-main sequence G0 star hosting a moderately bright debris disc ($L_{\rm dust}/L_{\star} \sim 2.6\times10^{-4}$). HD~105 and its surroundings might therefore be considered an analogue of the young Solar System. We refine the stellar ... More
Deep exploration of $ε$ Eridani with Keck Ms-band vortex coronagraphy and radial velocities: mass and orbital parameters of the giant exoplanetOct 09 2018Oct 29 2018We present the most sensitive direct imaging and radial velocity (RV) exploration of $\epsilon$ Eridani to date. $\epsilon$ Eridani is an adolescent planetary system, reminiscent of the early Solar system. It is surrounded by a prominent and complex debris ... More
Discovery of a low-mass companion inside the debris ring surrounding the F5V star HD206893Dec 01 2016Dec 04 2016Uncovering the ingredients and the architecture of planetary systems is a very active field of research that has fuelled many new theories on giant planet formation, migration, composition, and interaction with the circumstellar environment. We aim at ... More
Archival Legacy Investigations of Circumstellar Environments (ALICE): Statistical assessment of point source detectionsSep 25 2015The ALICE program, for Archival Legacy Investigation of Circumstellar Environment, is currently conducting a virtual survey of about 400 stars, by re-analyzing the HST-NICMOS coronagraphic archive with advanced post-processing techniques. We present here ... More
Neutral genomic regions refine models of recent rapid human population growthSep 25 2013Nov 15 2013Human populations have experienced dramatic growth since the Neolithic revolution. Recent studies that sequenced a very large number of individuals observed an extreme excess of rare variants, and provided clear evidence of recent rapid growth in effective ... More
Dynamic stratification in drying films of colloidal mixturesFeb 02 2016Mar 06 2016In simulations and experiments, we study the drying of films containing mixtures of large and small colloidal particles in water. During drying, the mixture stratifies into a layer of the larger particles at the bottom with a layer of the smaller particles ... More
Math in the Black Forest: Workshop on New Directions in Shape AnalysisNov 04 2018These are the proceedings of the workshop "Math in the Black Forest", which brought together researchers in shape analysis to discuss promising new directions. Shape analysis is an inter-disciplinary area of research with theoretical foundations in infinite-dimensional ... More
Correlated evolution of structure and mechanical loss of a sputtered silica filmJun 09 2017Energy dissipation in amorphous coatings severely affects high-precision optical and quantum transducers. In order to isolate the source of coating loss, we performed an extensive study of Raman scattering and mechanical loss of a thermally-treated sputtered ... More
Monitoring the orientation of rare-earth-doped nanorods for flow shear tomographyDec 06 2017Rare-earth phosphors exhibit unique luminescence polarization features originating from the anisotropic symmetry of the emitter ion's chemical environment. However, to take advantage of this peculiar property, it is necessary to control and measure the ... More
High-Reflection Coatings for Gravitational-Wave Detectors: State of The Art and Future DevelopmentsDec 14 2017We report on the optical, mechanical and structural characterization of the sputtered coating materials of Advanced LIGO, Advanced Virgo and KAGRA gravitational-waves detectors. We present the latest results of our research program aiming at decreasing ... More
The close environment of high-mass X-ray binaries at high angular resolution I. VLTI/AMBER and VLTI/PIONIER near-infrared interferometric observations of Vela X-1Nov 16 2013Recent improvements on the sensitivity and spectral resolution of X-ray observations have led to a better understanding of the properties of matter in the vicinity of High Mass X-ray Binaries hosting a supergiant star and a compact object. However the ... More