Results for "Audrey Coutens"

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New constraints on the initial parameters of low-mass star formation from chemical modelingMay 14 2019The complexity of physico-chemical models of star formation is increasing, with models that take into account new processes and more realistic setups. These models allow astrochemists to compute the evolution of chemical species throughout star formation. ... More
The ALMA-PILS survey: The sulphur connection between protostars and comets: IRAS 16293-2422 B and 67P/Churyumov-GerasimenkoFeb 08 2018Feb 21 2018The evolutionary past of our Solar System can be pieced together by comparing analogous low-mass protostars with remnants of our Protosolar Nebula - comets. Sulphur-bearing molecules may be unique tracers of the joint evolution of the volatile and refractory ... More
Detection of glycolaldehyde towards the solar-type protostar NGC1333 IRAS2AFeb 03 2015Glycolaldehyde is a key molecule in the formation of biologically relevant molecules such as ribose. We report its detection with the Plateau de Bure interferometer towards the Class 0 young stellar object NGC1333 IRAS2A, which is only the second solar-type ... More
Blind identification of an unknown interleaved convolutional codeJan 15 2015We give here an efficient method to reconstruct the block interleaver and recover the convolutional code when several noisy interleaved codewords are given. We reconstruct the block interleaver without assumption on its structure. By running some experimental ... More
Inducing odd-frequency triplet superconducting correlations in a normal metalJun 20 2011Sep 20 2011This work discusses theoretically the interplay between the superconducting and ferromagnetic proximity effects, in a diffusive normal metal strip in contact with a superconductor and a non-uniformly magnetized ferromagnetic insulator. The quasiparticle ... More
Rotational spectroscopy, dipole moment and $^{14}$N nuclear hyperfine structure of $iso$-propyl cyanideFeb 28 2011Rotational transitions of $iso$-propyl cyanide, (CH$_3$)$_2$CHCN, also known as $iso$-butyronitrile, were recorded using long-path absorption spectroscopy in selected regions between 37 and 600 GHz. Further measurements were carried out between 6 and ... More
High D$_2$O/HDO ratio in the inner regions of the low-mass protostar NGC1333 IRAS2AJul 25 2014Aug 16 2014Water plays a crucial role both in the interstellar medium and on Earth. To constrain its formation mechanisms and its evolution through the star formation process, the determination of the water deuterium fractionation ratios is particularly suitable. ... More
Protoplanetary disks: Sensitivity of the chemical composition to various model parametersJan 29 2019Protoplanetary disks are challenging objects for astrochemical models due to strong density and temperature gradients and due to the UV photons 2D propagation. In this paper, we have studied the importance of several model parameters on the predicted ... More
Spectroscopy and critical temperature of diffusive superconducting/ferromagnetic hybrid structures with spin-active interfacesApr 30 2007Nov 12 2007The description of the proximity effect in superconducting/ferromagnetic heterostructures requires to use spin-dependent boundary conditions. Such boundary conditions must take into account the spin dependence of the phase shifts acquired by electrons ... More
Probing coherent Cooper pair splitting with cavity photonsJun 18 2014Sep 18 2014This work discusses theoretically the behavior of a microwave cavity and a Cooper pair beam splitter (CPS) coupled non-resonantly. The cavity frequency pull is modified when the CPS is resonant with a microwave excitation. This provides a direct way to ... More
Gate-dependent spin-torque in a nanoconductor-based spin-valveJun 17 2011This article discusses the spin-torque effect in a spin-valve made out of two ferromagnetic leads connected through a coherent nanoconductor (NC), in the limit where a single channel of the NC lies near the Fermi energy of the leads. Due to quantum interferences ... More
Minimal seesaw models and minimal lepton flavor violationSep 13 2012We study the implications of the global $U(1)_R$ symmetry present in minimal lepton flavor violating implementations of the seesaw mechanism for neutrino masses. Our discussion is done in the context of explicit minimal type-I seesaw scenarios, where ... More
Goodness of fit statistics for sparse contingency tablesJun 14 2010Statistical data is often analyzed as a contingency table, sometimes with empty cells called zeros. Such sparse tables can be due to scarse observations classified in numerous categories, as for example in genetic association studies. Thus, classical ... More
Ends of Schreier graphs of hyperbolic groupsFeb 13 2018We study the number of ends of a Schreier graph of a hyperbolic group. Let G be a hyperbolic group and let H be a subgroup of G. In general, there is no algorithm to compute the number of ends of a Schreier graph of the pair (G, H). However, assuming ... More
The Auslander and Ringel-Tachikawa Theorem for submodule embeddingsMar 30 2009Auslander and Ringel-Tachikawa have shown that for an artinian ring R of finite representation type, every R-module is the direct sum of finitely generated indecomposable R-modules. In this paper, we will adapt this result to finite representation type ... More
Killing Forms of Isotropic Lie AlgebrasFeb 18 2010This paper presents a method for computing the Killing form of an isotropic Lie algebra defined over an arbitrary field based on the Killing form of a subalgebra containing its anisotropic kernel. This approach allows for streamlined formulas for many ... More
Water deuterium fractionation in the inner regions of two solar type protostarsApr 08 2013The [HDO]/[H2O] ratio is a crucial parameter for probing the history of water formation. So far, it has been measured for only three solar type protostars and yielded different results, possibly pointing to a substantially different history in their formation. ... More
Methyl isocyanate CH3NCO: An important missing organic in current astrochemical networksSep 28 2017Methyl isocyanate (CH3NCO) is one of the important complex organic molecules detected on the comet 67P/Churyumov-Gerasimenko by Rosetta's Philae lander. It was also detected in hot cores around high-mass protostars along with a recent detection in the ... More
Microwave spectroscopy of a Cooper pair beam splitterMay 10 2012This article discusses how to demonstrate the entanglement of the split Cooper pairs produced in a double-quantum-dot based Cooper pair beam splitter (CPS), by performing the microwave spectroscopy of the CPS. More precisely, one can study the DC current ... More
Goodness of fit statistics for sparse contingency tablesJun 11 2010Statistical data is often analyzed as a contingency table, sometimes with empty cells called zeros. Such sparse tables can be due to scarse observations classified in numerous categories, as for example in genetic association studies. Thus, classical ... More
Locally Adaptive Density Estimation on the Unit Sphere Using NeedletsApr 10 2011Dec 09 2013The problem of estimating a probability density function f on the (d-1)-dimensional unit sphere S^{d-1} from directional data using the needlet frame is considered. It is shown that the decay of needlet coefficients supported near a point of a function ... More
Methyl cyanide (CH3CN) and propyne (CH3CCH) in the low mass protostar IRAS 16293-2422Dec 13 2018Methyl cyanide (CH3CN) and propyne (CH3CCH) are two molecules commonly used as gas thermometers for interstellar gas. They are detected in several astrophysical environments and in particular towards protostars. Using data of the low-mass protostar IRAS ... More
A study of deuterated water in the low-mass protostar IRAS16293-2422Jan 09 2012Feb 16 2012The HDO/H2O ratio is a powerful diagnostic to understand the evolution of water from the first stages of star formation to the formation of planets and comets. Our aim is to determine precisely the abundance distribution of HDO towards the low-mass protostar ... More
A spin quantum bit with ferromagnetic contacts for circuit QEDMay 11 2010Oct 16 2010We theoretically propose a scheme for a spin quantum bit based on a double quantum dot contacted to ferromagnetic elements. Interface exchange effects enable an all electric manipulation of the spin and a switchable strong coupling to a superconducting ... More
The Swiss Cheese Theorem for Linear Operators with Two Invariant SubspacesSep 19 2014We study systems $(V,T,U_1,U_2)$ consisting of a finite dimensional vector space $V$, a nilpotent $k$-linear operator $T:V\to V$ and two $T$-invariant subspaces $U_1\subset U_2\subset V$. Let $\mathcal S(n)$ be the category of such systems where the operator ... More
Superconducting/ferromagnetic diffusive bilayer with a spin-active interface: a numerical studyOct 06 2008Dec 03 2008We calculate the density of states (DOS) in a diffusive superconducting/ferromagnetic bilayer with a spin-active interface. We use a self-consistent numerical treatment to make a systematic study of the effects of the Spin-Dependence of Interfacial Phase ... More
Cosmological expansion and local physicsJul 09 2007The interplay between cosmological expansion and local attraction in a gravitationally bound system is revisited in various regimes. First, weakly gravitating Newtonian systems are considered, followed by various exact solutions describing a relativistic ... More
Estimating intrinsic and extrinsic noise from single-cell gene expression measurementsJan 13 2016Gene expression is stochastic and displays variation ("noise") both within and between cells. Intracellular (intrinsic) variance can be distinguished from extracellular (extrinsic) variance by applying the law of total variance to data from two-reporter ... More
Conductance and current noise of a superconductor/ferromagnet quantum point contactFeb 22 2008We study the conductance and current noise of a superconductor/ferromagnet (S/F) single channel Quantum Point Contact (QPC) as a function of the QPC bias voltage, using a scattering approach. We show that the Spin-Dependence of Interfacial Phase Shifts ... More
Superconducting proximity effect in a diffusive ferromagnet with spin-active interfacesMay 17 2005Sep 20 2005We reconsider the problem of the superconducting proximity effect in a diffusive ferromagnet bounded by tunneling interfaces, using spin-dependent boundary conditions. This introduces for each interface a phase-shifting conductance Gphi which results ... More
Instability zones for satellites of asteroids. The example of the (87) Sylvia systemDec 22 2011We study the stability of the (87) Sylvia system and of the neighborhood of its two satellites. We use numerical integrations considering the non-sphericity of Sylvia, as well as the mutual perturbation of the satellites and the solar perturbation. Two ... More
Did the universe have a beginning?Apr 20 2012We discuss three candidate scenarios which seem to allow the possibility that the universe could have existed forever with no initial singularity: eternal infation, cyclic evolution, and the emergent universe. The first two of these scenarios are geodesically ... More
Estimating Quality in Multi-Objective Bandits OptimizationJan 04 2017Apr 20 2017Many real-world applications are characterized by a number of conflicting performance measures. As optimizing in a multi-objective setting leads to a set of non-dominated solutions, a preference function is required for selecting the solution with the ... More
From 2G TO 3G - The Evolution of International Cellular StandardsOct 22 2001The purpose of this paper is to examine the major factors surrouding and contributing to the creation (and success) of Europe's 2nd generation 'GSM' cellular system, and compare and contrast it to key events and recent developments in 3rd generation 'IMT-2000' ... More
Pebble Game Algorithms and Sparse GraphsFeb 06 2007A multi-graph $G$ on $n$ vertices is $(k,\ell)$-sparse if every subset of $n'\leq n$ vertices spans at most $kn'- \ell$ edges. $G$ is {\em tight} if, in addition, it has exactly $kn - \ell$ edges. For integer values $k$ and $\ell \in [0, 2k)$, we characterize ... More
A tighter Erdös-Pósa function for long cyclesMay 04 2012We prove that there exists a bivariate function f with f(k,l) = O(l k log k) such that for every naturals k and l, every graph G has at least k vertex-disjoint cycles of length at least l or a set of at most f(k,l) vertices that meets all cycles of length ... More
Inflation with negative potentials and the signature reversal symmetryFeb 04 2013Apr 01 2013We discuss recent papers by Hartle, Hawking and Hertog, which proposed that quantum cosmology could predict an inflating universe in models with negative scalar potentials. Here we show that this is a result of an underlying symmetry which is manifest ... More
Lightcurves and Rotational Properties of the Pristine Cold Classical Kuiper Belt ObjectsApr 03 2019We present a survey on the rotational and physical properties of the dynamically low inclination Cold Classical trans-Neptunian objects. The Cold Classicals (CCs) are primordial planetesimals and contain relevant information about the early phase of our ... More
Tunneling decay rate in quantum cosmologyMar 02 2015In canonical quantum cosmology, the wave function of the universe lacks explicit time dependence. However, time evolution may be present implicitly through the semiclassical superspace variables, which themselves depend on time in classical dynamics. ... More
Collapse of simple harmonic universeOct 18 2011Dec 16 2011In a recent paper Graham et al constructed oscillating and static universe models which are stable with respect to all classical perturbations. Here we show that such universes are quantum-mechanically unstable and can collapse by quantum tunneling to ... More
A Class of Randomized Primal-Dual Algorithms for Distributed OptimizationJun 24 2014Oct 25 2014Based on a preconditioned version of the randomized block-coordinate forward-backward algorithm recently proposed in [Combettes,Pesquet,2014], several variants of block-coordinate primal-dual algorithms are designed in order to solve a wide array of monotone ... More
A truly Newtonian softening length for disc simulationsNov 26 2014The softened point mass model is commonly used in simulations of gaseous discs including self-gravity while the value of associated length \lambda remains, to some degree, controversial. This ``parameter'' is however fully constrained when, in a discretized ... More
Observable Features of Tachyon-Dominated CosmologyApr 15 2019A Friedman-Robertson-Walker cosmological model dominated by tachyonic---faster-than-light---dark matter can exhibit features similar to those of a standard dark energy/dark matter or Lambda-CDM model. For example, it can undergo expansion which decelerates ... More
Stablizing oscillating universes against quantum decayJul 21 2014We investigate the effect of vacuum corrections, due to the trace anomaly and Casimir effect, on the stability of an oscillating universe with respect to decay by tunneling to the singularity. We find that these corrections do not generally stabilize ... More
Instability of an emergent universeMar 04 2014Mar 20 2014Oscillating solutions to the effective equations of Loop Quantum Cosmology have been suggested for the role of an `eternal seed', providing a possible starting point for the emergent universe scenario. We investigate the stability of a particular model, ... More
Magnetoresistance of a quantum dot with spin-active interfacesMay 10 2006Oct 12 2006We study the zero-bias magnetoresistance MR of an interacting quantum dot connected to two ferromagnetic leads and capacitively coupled to a gate voltage source Vg. We investigate the effects of the spin-activity of the contacts between the dot and the ... More
Water deuterium fractionation in the high-mass star-forming region G34.26+0.15 based on Herschel/HIFI dataSep 03 2014Understanding water deuterium fractionation is important for constraining the mechanisms of water formation in interstellar clouds. Observations of HDO and H$_2^{18}$O transitions were carried out towards the high-mass star-forming region G34.26+0.15 ... More
Self-gravity in curved mesh elementsJan 13 2014The local character of self-gravity along with the number of spatial dimensions are critical issues when computing the potential and forces inside massive systems like stars and disks. This appears from the discretisation scale where each cell of the ... More
Mesoscopic admittance of a double quantum dotNov 01 2010Mar 28 2011We calculate the mesoscopic admittance $G(\omega)$ of a double quantum dot (DQD),which can be measured directly using microwave techniques. This quantity reveals spectroscopic information on the DQD and is also directly sensitive to a Pauli spin blockade ... More
Nature vs. Nurture: The Role of Environmental Resources in Evolutionary Deep IntelligenceFeb 09 2018Evolutionary deep intelligence synthesizes highly efficient deep neural networks architectures over successive generations. Inspired by the nature versus nurture debate, we propose a study to examine the role of external factors on the network synthesis ... More
The ALMA-PILS survey: The sulphur connection between protostars and comets: IRAS 16293-2422 B and 67P/Churyumov-GerasimenkoFeb 08 2018The evolutionary past of our Solar System can be pieced together by comparing analogous low-mass protostars with remnants of our Protosolar Nebula - comets. Sulphur-bearing molecules may be unique tracers of the joint evolution of the volatile and refractory ... More
Squeezing light with Majorana fermionsJul 16 2013Nov 12 2013Coupling a semiconducting nanowire to a microwave cavity provides a powerfull means to assess the presence or absence of isolated Majorana fermions in the nanowire. These exotic bound states can cause a significant cavity frequency shift but also a strong ... More
Finite frequency noise of a superconductor/ferromagnet quantum point contactMar 06 2008Nov 27 2008We have calculated the finite-frequency current noise of a superconductor-ferromagnet quantum point contact (SF QPC). This signal is qualitatively affected by the spin-dependence of interfacial phase shifts (SDIPS) acquired by electrons upon reflection ... More
Subradiant split Cooper pairsNov 30 2011Apr 04 2012We suggest a way to characterize the coherence of the split Cooper pairs emitted by a double-quantum-dot based Cooper pair splitter (CPS), by studying the radiative response of such a CPS inside a microwave cavity. The coherence of the split pairs manifests ... More
Geometric minimization of highly symmetric potentialsNov 21 2012Apr 29 2013In non-minimal Higgs mechanisms, one often needs to minimize highly symmetric Higgs potentials. Here we propose a geometric way of doing it, which, surprisingly, is often much more efficient than the usual method. By construction, it gives the global ... More
A regularized tri-linear approach for optical interferometric imagingSep 02 2016In the context of optical interferometry, only under-sampled power spectrum and bispectrum data are accessible. It poses an ill-posed inverse problem for image recovery. Recently, a tri-linear model was proposed for monochromatic imaging, leading to an ... More
Biomimetic bluff body drag reduction by self-adaptive porous flapsJul 25 2011The performances of an original passive control system based on a biomimetic approach are assessed by investigating the flow over a bluff-body. This control device consists in a couple of flaps made from the combination of a rigid plastic skeleton coated ... More
Streaming kernel regression with provably adaptive mean, variance, and regularizationAug 02 2017We consider the problem of streaming kernel regression, when the observations arrive sequentially and the goal is to recover the underlying mean function, assumed to belong to an RKHS. The variance of the noise is not assumed to be known. In this context, ... More
Mitigating Architectural Mismatch During the Evolutionary Synthesis of Deep Neural NetworksNov 19 2018Evolutionary deep intelligence has recently shown great promise for producing small, powerful deep neural network models via the organic synthesis of increasingly efficient architectures over successive generations. Existing evolutionary synthesis processes, ... More
Multi-terminal spin-dependent transport in ballistic carbon nanotubesMar 23 2009We study theoretically nonlocal spin transport in a ballistic carbon nanotube contacted to two ferromagnetic leads and two normal-metal leads. When the magnetizations of the two ferromagnets are changed from a parallel to an antiparallel configuration, ... More
Sparse interferometric Stokes imaging under polarization constraint (Polarized SARA)Jan 08 2018We develop a novel algorithm for sparse Stokes parameters imaging in radio interferometry under the polarization constraint. The latter is a physical non-linear relation between the Stokes parameters, imposing that the polarization intensity is a lower ... More
Capillary force on a tilted cylinder: AFM measurementsFeb 22 2017We investigate the capillary force that applies on a tilted cylinder as a function of its dipping angle i, using a home-built tilting Atomic Force Microscope (AFM) with custom made probes. A micrometric-size rod is glued at the end of an AFM cantilever ... More
Logics of Temporal-Epistemic ActionsNov 23 2014We present Dynamic Epistemic Temporal Logic, a framework for reasoning about operations on multi-agent Kripke models that contain a designated temporal relation. These operations are natural extensions of the well-known "action models" from Dynamic Epistemic ... More
Electron-photon coupling in Mesoscopic Quantum ElectrodynamicsJan 05 2015May 09 2015Understanding the interaction between cavity photons and electronic nanocircuits is crucial for the development of Mesoscopic Quantum Electrodynamics (QED). One has to combine ingredients from atomic Cavity QED, like orbital degrees of freedom, with tunneling ... More
Optical dispersion of composite particles consisting of millicharged constituentsJul 15 2016Composite dark matter (DM) comprised of electrically charged constituents can interact with the electromagnetic field via the particle's dipole moment. This interaction results in a dispersive optical index of refraction for the DM medium. We compute ... More
Functionalized AFM probes for force spectroscopy: eigenmodes shape and stiffness calibration through thermal noise measurementsFeb 11 2013May 08 2013The functionalization of an Atomic Force Microscope (AFM) cantilever with a colloidal bead is a widely used technique when the geometry between the probe and the sample must be controlled, particularly in force spectroscopy. But some questions remain: ... More
A regularized tri-linear approach for optical interferometric imagingSep 02 2016Jul 10 2017In the context of optical interferometry, only undersampled power spectrum and bispectrum data are accessible. It poses an ill-posed inverse problem for image recovery. Recently, a tri-linear model was proposed for monochromatic imaging, leading to an ... More
Polca SARA - Full polarization, direction-dependent calibration and sparse imaging for radio interferometryApr 01 2019New generation of radio interferometers are envisaged to produce high quality, high dynamic range Stokes images of the observed sky from the corresponding under-sampled Fourier domain measurements. In practice, these measurements are contaminated by the ... More
Reanalyzing the visible colors of Centaurs and KBOs: what is there and what we might be missingFeb 13 2015Visible colors (BVRI) are a reasonable proxy for real spectra of Centaurs and Kuiper Belt Objects, which are rather linear in this range. Colors provide limited information but remain the best tool to study the bulk surface properties. We explore recurrent ... More
Assessing Architectural Similarity in Populations of Deep Neural NetworksApr 19 2019Evolutionary deep intelligence has recently shown great promise for producing small, powerful deep neural network models via the synthesis of increasingly efficient architectures over successive generations. Despite recent research showing the efficacy ... More
An Experiment About Parallel Circuit And The Lorentz Forces On WiresOct 27 2015Parallel circuit and the Lorentz forces on current carrying wires are important concepts in introductory physics courses. Here we describe an experiment that illustrates these two concepts. We mount a circuit with multiple grounding points onto a torsion ... More
Astrophysical constraints on millicharged atomic dark matterDec 01 2014Some models of inelastic dark matter posit the existence of bound states under some new $U(1)'$ gauge symmetry. If this new dark photon kinetically mixes with the standard model photon, then the constituent particles in these bound states can acquire ... More
Primordial Perturbations from Multifield Inflation with Nonminimal CouplingsApr 21 2010Sep 24 2010Realistic models of particle physics include many scalar fields. These fields generically have nonminimal couplings to the Ricci curvature scalar, either as part of a generalized Einstein theory or as necessary counterterms for renormalization in curved ... More
Self-gravity in thin discs and edge effects: an extension of Paczynski's approximationJan 13 2014As hydrostatic equilibrium of gaseous discs is partly governed by the gravity field, we have estimated the component caused by a vertically homogeneous disc, with a special attention for the outer regions where self-gravity classically appears. The accuracy ... More
Combinatorics and the Rigidity of CAD SystemsOct 01 2012Oct 17 2012We study the rigidity of body-and-cad frameworks which capture the majority of the geometric constraints used in 3D mechanical engineering CAD software. We present a combinatorial characterization of the generic minimal rigidity of a subset of body-and-cad ... More
Graded Sparse Graphs and MatroidsNov 19 2007Dec 21 2007Sparse graphs and their associated matroids play an important role in rigidity theory, where they capture the combinatorics of generically rigid structures. We define a new family called {\bf graded sparse graphs}, arising from generically pinned (completely ... More
Scalable Bayesian uncertainty quantification in imaging inverse problems via convex optimizationMar 02 2018Nov 06 2018We propose a Bayesian uncertainty quantification method for large-scale imaging inverse problems. Our method applies to all Bayesian models that are log-concave, where maximum-a-posteriori (MAP) estimation is a convex optimization problem. The method ... More
Eppur si espandeDec 06 2006Apr 11 2007The rather wide-spread belief that cosmological expansion of a flat 3D--space (with spatial curvature k=0) cannot be observationally distinguished from a kinematics of galaxies moving in a flat and non-expanding space is erroneous. We suggest that the ... More
A short answer to critics of our article "Eppur si espande" [arXiv:astro-ph/0612155]Dec 17 2008Recently [arXiv:astro-ph/0612155] we presented a formal mathematical proof that, contrary to a widespread misconception, cosmological expansion cannot be understood as the motion of galaxies in non-expanding space. We showed that the cosmological redshift ... More
Microrheology measurements with a hanging-fiber AFM probeNov 09 2013A method to measure the viscosity of liquids at microscales is presented. It uses a thin glass fiber fixed on the tip of the cantilever of an extremely low noise Atomic Force Microscope (AFM), which accurately measures the cantilever {deflection}. When ... More
MRPC: An R package for accurate inference of causal graphsJun 05 2018We present MRPC, an R package that learns causal graphs with improved accuracy over existing packages, such as pcalg and bnlearn. Our algorithm builds on the powerful PC algorithm, the canonical algorithm in computer science for learning directed acyclic ... More
First experimental data of sulphur ions sputtering water iceApr 25 2018This paper presents the first experimental sputtering yields for sulphur ions with energies between 10 keV and 140 keV irradiating water ice films on a microbalance. The measured sputtering yields exceed theoretical predictions based on other ion species ... More
EdgeSpeechNets: Highly Efficient Deep Neural Networks for Speech Recognition on the EdgeOct 18 2018Nov 13 2018Despite showing state-of-the-art performance, deep learning for speech recognition remains challenging to deploy in on-device edge scenarios such as mobile and other consumer devices. Recently, there have been greater efforts in the design of small, low-footprint ... More
Toward Biochemical Probabilistic ComputationNov 09 2015Living organisms survive and multiply even though they have uncertain and incomplete information about their environment and imperfect models to predict the consequences of their actions. Bayesian models have been proposed to face this challenge. Indeed, ... More
Charged fluid structures around a rotating compact object with a magnetic dipole fieldApr 30 2018We study stationary, electrically charged fluid structures encircling a rotating compact object with a dipole magnetic field oriented along the rotation axis. This situation is described in an idealized way by the Kerr metric and a magnetic dipole "test" ... More
Dynamics of the freezing front during the solidification of a colloidal alumina aqueous suspension: in situ X-ray radiography, tomography and modelingMar 29 2018Ice templating of colloidal suspension is gaining interest in material science because it offers the possibility to shape advanced materials, and in particular porous ceramics. Recent investigations on this peculiar process show that a correlation between ... More
Optimal undulating swimming for a single fish-like body and for a pair of interacting swimmersApr 04 2016We establish through numerical simulation conditions for optimal undulatory propulsion for a single fish, and for a pair of hydrodynamically interacting fish, accounting for linear and angular recoil. We first employ systematic 2D simulations to identify ... More
Assessing Time-Varying Causal Effect Moderation in Mobile HealthJan 03 2016Aug 17 2016In mobile health interventions aimed at behavior change and maintenance, treatments are provided in real time to manage current or impending high risk situations or promote healthy behaviors in near real time. Currently there is great scientific interest ... More
Optimal traffic organisation in ants under crowded conditionsMar 04 2004Efficient transportation, a hot topic in nonlinear science, is essential for modern societies and the survival of biological species. Biological evolution has generated a rich variety of successful solutions, which have inspired engineers to design optimized ... More
Non-convex optimization for self-calibration of direction-dependent effects in radio interferometric imagingJan 13 2017Jul 24 2017Radio interferometric imaging aims to estimate an unknown sky intensity image from degraded observations, acquired through an antenna array. In the theoretical case of a perfectly calibrated array, it has been shown that solving the corresponding imaging ... More
Minimal lepton flavor violating realizations of minimal seesaw modelsMay 24 2012Aug 22 2012We study the implications of the global U(1)R symmetry present in minimal lepton flavor violating implementations of the seesaw mechanism for neutrino masses. In the context of minimal type I seesaw scenarios with a slightly broken U(1)R, we show that, ... More
Rotation set and EntropyNov 29 2007Apr 25 2009In 1991 Llibre and MacKay proved that if $f$ is a 2-torus homeomorphism isotopic to identity and the rotation set of $f$ has a non empty interior then $f$ has positive topological entropy. Here, we give a converselike theorem. We show that the interior ... More
Mutation classes of skew-symmetric 3x3-matricesOct 20 2006In this paper, we establish a bijection between the set of mutation classes of mutation-cyclic skew-symmetric integral 3x3-matrices and the set of triples of integers (a,b,c) which are all greater than 1 and where the product of the two smaller numbers ... More
Hard X-rays and Fluorescent Iron Emission from the Embedded Infrared Cluster in NGC 2071Dec 19 2006We present first results of XMM-Newton X-ray observations of the infrared cluster lying near the NGC 2071 reflection nebula in the Orion B region. This cluster is of interest because it is one of the closest regions known to harbor embedded high-mass ... More
SED-dependent Galactic Extinction Prescription for Euclid and Future Cosmological SurveysSep 27 2016The outcome of upcoming cosmological surveys will depend on the accurate estimates of photometric redshifts. In the framework of the implementation of the photo-z algorithm for Euclid, we are exploring new avenues to improve template-fitting methods. ... More
Analytical and Numerical Investigation of Ant Behavior Under Crowded ConditionsOct 25 2008Swarm intelligence is widely recognized as a powerful paradigm of self-organized optimization, with numerous examples of successful applications in distributed artificial intelligence. However, the role of physical interactions in the organization of ... More
Temporal Regularization in Markov Decision ProcessNov 01 2018Several applications of Reinforcement Learning suffer from instability due to high variance. This is especially prevalent in high dimensional domains. Regularization is a commonly used technique in machine learning to reduce variance, at the cost of introducing ... More
Model of collective fish behavior with hydrodynamic interactionsMay 22 2017May 03 2018Fish schooling is often modeled with self-propelled particles subject to phenomenological behavioral rules. Although fish are known to sense and exploit flow features, these models usually neglect hydrodynamics. Here, we propose a novel model that couples ... More
Particles redistribution and structural defects development during ice templatingMar 29 2018The freezing of colloidal suspensions is encountered in many natural and engineering processes. It can be harnessed through a process known as ice templating, to produce porous materials and composites exhibiting unique functional properties. The phenomenon ... More
Characterizing Sparse Graphs by Map DecompositionsApr 29 2007A {\bf map} is a graph that admits an orientation of its edges so that each vertex has out-degree exactly 1. We characterize graphs which admit a decomposition into $k$ edge-disjoint maps after: (1) the addition of {\it any} $\ell$ edges; (2) the addition ... More