Guillet, T., Teyssier, R., Colombi, S.
We study the dissipative effects of baryon physics on cosmic statistics at small scales using a cosmological simulation of a (50 Mpc/h)^3 volume of the universe. The MareNostrum simulation was...
Building Merger Trees from Cosmological N-body Simulations (2009)
Tweed, D., Devriendt, J., Blaizot, J., Colombi, S., Slyz, A.
Although a fair amount of work has been devoted to growing Monte-Carlo merger trees which resemble those built from an N-body simulation, comparatively little effort has been invested in quantifying...
ASKI: towards a full-sky lensing map making pipeline (2009)
Pichon, C., Thiebaut, E., Prunet, S., Benabed, K., Colombi, S., Sousbie, T., ...
Within the context of upcoming full-sky lensing surveys, the edge-preserving non- linear algorithm Aski is presented. Using the framework of Maximum A Posteriori inversion, it recovers the full-sky...
Phase-space structures – I. A comparison of 6D density estimators (2009)
Maciejewski, M., Colombi, S., Alard, C., Bouchet, F., Pichon, C.
Phase-space structures – II. Hierarchical structure finder (2009)
Maciejewski, M., Colombi, S., Springel, V., Alard, C., Bouchet, F. R.
Phase-space structures II: Hierarchical Structure Finder (2008)
Maciejewski, M., Colombi, S., Springel, V., Alard, C., Bouchet, F. R.
A new multi-dimensional Hierarchical Structure Finder (HSF) to study the phase-space structure of dark matter in N-body cosmological simulations is presented. The algorithm depends mainly on two...
The Local Theory of the Cosmic Skeleton (2008)
Pogosyan, D., Pichon, C., Gay, C., Prunet, S., Cardoso, J. F., Sousbie, T., ...
The local theory of the critical lines of 2D and 3D Gaussian fields that underline the cosmic structures is presented. In the context of cosmological matter distribution the subset of critical lines...
Lavaux, G., Tully, R. Brent, Mohayaee, R., Colombi, S.
We generate the peculiar velocity field for the 2MASS Redshift Survey (2MRS) catalog using an orbit-reconstruction algorithm. The reconstructed velocities of individual objects in 2MRS are...
Phase-space structures I: A comparison of 6D density estimators (2008)
Maciejewski, M., Colombi, S., Alard, C., Bouchet, F., Pichon, C.
This paper reviews and analyses methods used to identify neighbours in 6D space and estimate the corresponding phase-space density. It compares SPH methods to 6D Delaunay tessellation on statical and...
The fully connected N-dimensional skeleton: probing the evolution of the cosmic web (2008)
Sousbie, T., Colombi, S., Pichon, C.
A method to compute the full hierarchy of the critical subsets of a density field is presented. It is based on a watershed technique and uses a probability propagation scheme to improve the quality...
Recovering the topology of the IGM at z~2 (2008)
Caucci, S., Colombi, S., Pichon, C., Rollinde, E., Petitjean, P., Sousbie, T.
We investigate how well the 3D density field of neutral hydrogen in the Intergalactic Medium (IGM) can be reconstructed using the Lyman-alpha absorptions observed along lines of sight to quasars...
Using Local Volume data to constrain Dark Matter dynamics (2007)
Lavaux, G., Mohayaee, R., Colombi, S., Tully, R. B.
The peculiar velocity reconstruction methods allow one to have a deeper insight into the distribution of dark matter: both to measure mean matter density and to obtain the primordial density...
Observational biases in Lagrangian reconstructions of cosmic velocity fields (2007)
Lavaux, G., Mohayaee, R., Colombi, S., Tully, R. B., Bernardeau, F., Silk, J.
Lagrangian reconstruction of large-scale peculiar velocity fields can be strongly affected by observational biases. We develop a thorough analysis of these systematic effects by relying on specially...
The three dimensional skeleton: tracing the filamentary structure of the universe (2007)
Sousbie, T., Pichon, C., Colombi, S., Novikov, D., Pogosyan, D.
The skeleton formalism aims at extracting and quantifying the filamentary structure of the universe is generalized to 3D density fields; a numerical method for computating a local approximation of...
Coppolani, F., Petitjean, P., Stoehr, F., Rollinde, E., Pichon, C., Colombi, S., ...
We present the transverse flux correlation function of the Lyman-alpha forest in quasar absorption spectra at z~2.1 from VLT-FORS and VLT-UVES observations of a total of 32 pairs of quasars; 26 pairs...
GalICS V : Low and high order clustering in mock SDSS's (2006)
Blaizot, J., Szapudi, I., Colombi, S., Budavari, T., Bouchet, F. R., Devriendt, J. E. G., ...
[Abridged] We use mock catalogues based on the GALICS model (Hatton et al. 03) to explore the nature of galaxy clustering observed in the SDSS. We measure low and high order angular clustering...
Le Fevre, O., Guzzo, L., Meneux, B., Pollo, A., Cappi, A., Colombi, S., ...
This paper presents the evolution of the clustering of the main population of galaxies from z=2.1 to z=0.2, from the first epoch VIMOS VLT Deep Survey (VVDS), a magnitude limited sample with 17.5
The VIMOS VLT Deep Survey: Evolution of the non-linear galaxy bias up to z=1.5 (2005)
Marinoni, C., Fevre, O. Le, Meneux, B., Iovino, A., Pollo, A., Ilbert, O., ...
We present the first measurements of the Probability Distribution Function (PDF) of galaxy fluctuations in the VIMOS-VLT Deep Survey (VVDS) cone, covering 0.4x0.4 deg between 0.4
MoMaF : The Mock Map Facility (2005)
Blaizot, J., Wadadekar, Y., Guiderdoni, B., Colombi, S., Bertin, E., Bouchet, F. R., ...
We present the Mock Map Facility, a powerful tool to generate mock catalogues or images from semi-analytically post-processed snapshots of cosmological N-body simulations. The paper describes in...
The correlation of the Lyman-alpha forest and metals in close pairs of hight-redshift quasars (2005)
Coppolani, F., Petitjean, P., Stoehr, F., Rollinde, E., Pichon, C., Colombi, S., ...
We derive the transverse flux correlation function in the Lyman-alpha forest at z~2.1 from VLT-FORS observations of a total of 32 pairs of quasars. The shape and correlation length of the transverse...
A cloudy Vlasov solution (2005)
We propose to integrate the Vlasov-Poisson equations giving the evolution of a dynamical system in phase-space using a continuous set of local basis functions. In practice, the method decomposes the...
The VIMOS VLT Deep Survey: Evolution of the non-linear galaxy bias up to z=1.5 (2005)
Marinoni, C., Fevre, O. Le, Meneux, B., Iovino, A., Pollo, A., Ilbert, O., ...
We present the first measurements of the Probability Distribution Function (PDF) of galaxy fluctuations in the VIMOS-VLT Deep Survey (VVDS) cone, covering 0.4x0.4 deg between 0.4
Cattaneo, A., Combes, F., Colombi, S., Bertin, E.
We present a method for generating virtual observations from smoothed-particle-hydrodynamics (SPH) simulations. This method includes stellar population synthesis models and the reprocessing of...
Le Fevre, O., Guzzo, L., Meneux, B., Pollo, A., Cappi, A., Colombi, S., ...
This paper presents the evolution of the clustering of the main population of galaxies from z=2.1 to z=0.2, from the first epoch VIMOS VLT Deep Survey (VVDS), a magnitude limited sample with 17.5
The VIMOS VLT Deep Survey: Evolution of the non-linear galaxy bias up to z=1.5 (2005)
Marinoni, C., Fevre, O. Le, Meneux, B., Iovino, A., Pollo, A., Ilbert, O., ...
We present the first measurements of the Probability Distribution Function (PDF) of galaxy fluctuations in the VIMOS-VLT Deep Survey (VVDS) cone, covering 0.4x0.4 deg between 0.4
MoMaF : The Mock Map Facility (2005)
Blaizot, J., Wadadekar, Y., Guiderdoni, B., Colombi, S., Bertin, E., Bouchet, F. R., ...
We present the Mock Map Facility, a powerful tool to generate mock catalogues or images from semi-analytically post-processed snapshots of cosmological N-body simulations. The paper describes in...
Le Fevre, O., Guzzo, L., Meneux, B., Pollo, A., Cappi, A., Colombi, S., ...
This paper presents the evolution of the clustering of the main population of galaxies from z=2.1 to z=0.2, from the first epoch VIMOS VLT Deep Survey (VVDS), a magnitude limited sample with 17.5
The VIMOS VLT Deep Survey: Evolution of the non-linear galaxy bias up to z=1.5 (2005)
Marinoni, C., Fevre, O. Le, Meneux, B., Iovino, A., Pollo, A., Ilbert, O., ...
We present the first measurements of the Probability Distribution Function (PDF) of galaxy fluctuations in the VIMOS-VLT Deep Survey (VVDS) cone, covering 0.4x0.4 deg between 0.4
MoMaF : The Mock Map Facility (2005)
Blaizot, J., Wadadekar, Y., Guiderdoni, B., Colombi, S., Bertin, E., Bouchet, F. R., ...
We present the Mock Map Facility, a powerful tool to generate mock catalogues or images from semi-analytically post-processed snapshots of cosmological N-body simulations. The paper describes in...
Le Fèvre, O., Guzzo, L., Meneux, B., Pollo, A., Cappi, A., Colombi, S., ...
The VIMOS VLT deep survey: evolution of the non-linear galaxy bias up to z = 1.5 (2005)
Marinoni, C., Le Fèvre, O., Meneux, B., Iovino, A., Pollo, A., Ilbert, O., ...
Fevre, O. Le, Guzzo, L., Meneux, B., Pollo, A., Cappi, A., Colombi, S., ...
This paper presents the evolution of the clustering of the main population of galaxies from z=2.1 to z=0.2, from the first epoch VIMOS VLT Deep Survey (VVDS), a magnitude limited sample with 17.5
A cloudy Vlasov solution (2004)
We propose to integrate the Vlasov-Poisson equations giving the evolution of a dynamical system in phase-space using a continuous set of local basis functions. In practice, the method decomposes the...
A cloudy Vlasov solution (2004)
We propose to integrate the Vlasov-Poisson equations giving the evolution of a dynamical system in phase-space using a continuous set of local basis functions. In practice, the method decomposes the...
A cloudy Vlasov solution (2004)
We propose to integrate the Vlasov-Poisson equations giving the evolution of a dynamical system in phase-space using a continuous set of local basis functions. In practice, the method decomposes the...
MoMaF : The Mock Map Facility (2003)
Blaizot, J., Wadadekar, Y., Guiderdoni, B., Colombi, S., Bertin, E., Bouchet, F. R., ...
We present the Mock Map Facility, a powerful tool to generate mock catalogues or images from semi-analytically post-processed snapshots of cosmological N-body simulations. The paper describes in...
Rollinde, E., Petitjean, P., Pichon, C., Colombi, S., Aracil, B., D'Odorico, V., ...
We study the clustering of matter in the intergalactic medium from the Lyman-alpha forests seen in the spectra of pairs or groups of z ~ 2 quasars observed with FORS2 and UVES at the VLT-UT2 Kueyen...
Probing CMB Non-Gaussianity Using Local Curvature (2002)
Doré, O., Colombi, S., Bouchet, F. R.
It is possible to classify pixels of a smoothed cosmic microwave background (CMB) fluctuation map according to their local curvature in ``hill'', ``lake'' and ``saddle'' regions. In the Gaussian...
JOE : A mobile, Inverted Pendulum (2002)
Grasser, F., D'Arrigo, A., Colombi, S., Rufer, A.
The Industrial Electronics Laboratory at the Swiss Federal Institute of Technology, Lausanne, Switzerland, has built a prototype of a revolutionary two-wheeled vehicle. Due to its configuration with...
Large-Scale Structure of the Universe and Cosmological Perturbation Theory (2001)
Bernardeau, F., Colombi, S., Gaztanaga, E., Scoccimarro, R.
We review the formalism and applications of non-linear perturbation theory (PT) to understanding the large-scale structure of the Universe. We first discuss the dynamics of gravitational instability,...
Measuring the Redshift Evolution of Clustering: the Hubble Deep Field South (2001)
Arnouts, S., Moscardini, L., Vanzella, E., Colombi, S., Cristiani, S., Fontana, A., ...
We present an analysis of the evolution of galaxy clustering in the redshift interval 0
Fast Clustering Analysis of Inhomogeneous Megapixel CMB maps (2001)
Szapudi, I., Prunet, S., Colombi, S.
Szapudi et al (2001) introduced the method of estimating angular power spectrum of the CMB sky via heuristically weighted correlation functions. Part of the new technique is that all (co)variances...
Inversion of the Lyman-$\alpha$ forest: 3D investigation of the intergalactic medium (2001)
Pichon, C., Vergely, J. L., Rollinde, E., Colombi, S., Petitjean, P.
We discuss the implementation of Bayesian inversion methods in order to recover the properties of the intergalactic medium from observations of the neutral hydrogen Lyman-$\alpha$ absorptions...
The VIRMOS-VLT Deep Survey (2001)
Fèvre, O. Le, Vettolani, G., Maccagni, D., Mancini, D., Mazure, A., Mellier, Y., ...
The aim of the VIRMOS VLT Deep Survey (VVDS) is to study of the evolution of galaxies, large scale structures and AGNs from a sample of more than 150,000 galaxies with measured redshifts in the range...
JOE : A mobile, Inverted Pendulum (2001)
Grasser, F., D'Arrigo, A., Colombi, S., Rufer, A.
The Industrial Electronics Laboratory at the Swiss Federal Institute of Technology (EPFL) in Lausanne has built a prototype of a revolutionary two-wheeled vehicle. Due to its configuration with two...
Weak Lensing Predictions at Intermediate Scales (2000)
Van Waerbeke, L., Hamana, T., Scoccimarro, R., Colombi, S., Bernardeau, F.
As pointed out in previous studies, the measurement of the skewness of the convergence field $\kappa$ will be useful in breaking the degeneracy among the cosmological parameters constrained from weak...
Cosmic Statistics of Statistics (1999)
Szapudi, I., Colombi, S., Bernardeau, F.
The errors on statistics measured in finite galaxy catalogs are exhaustively investigated. The theory of errors on factorial moments by Szapudi & Colombi (1996) is applied to cumulants via a series...
Colombi, S., Rufer, A., Zayadine, M., Girardin, M., D'Arrigo, A.
La sustentation et le guidage magnétique ont plusieurs applications industrielles: véhicules à haute vitesse, machines-outils, paliers magnétiques et convoyeurs. Dans cet article, on compare...
The Cosmic Distribution of Clustering (1998)
Colombi, S., Szapudi, I., Consortium, The VIRGO
For a given statistic, A, the cosmic distribution function, Upsilon(VA), is the probability of measuring a value VA in a finite galaxy catalog. For statistics related to count-in-cells, such as...
Control Strategies for the Electromagnetic Levitated and Guided Vehicles of SwissMetro (1998)
Colombi, S., Rufer, A., Zayadine, M., Girardin, M.
Electromagnetic levitated and guided system are commonly used in the field of high speed vehicles, tool machines, frictionless bearings and conveyor systems. This paper compares various control...
Quand la mécatronique réinvente les systèmes mécaniques (1998)
Quand la méchanique, l'électronique et l'inforamtique s'allient, elles donnent naissance à un nouvelle science appelée mécatronique. Combinée au remplacement de transmissions mécaniques par...
Effects of Sampling on Statistics of Large Scale Structure (1997)
Colombi, S., Szapudi, I., Szalay, A. S.
The effects of sampling are investigated on measurements of counts-in-cells in three-dimensional magnitude limited galaxy surveys, with emphasis on moments of the underlying smooth galaxy density...
Multivariable design of bilateral Master-Slave force reflecting servomechanisms (1997)
Bilateral Master-Slave force reflecting servomechanisms are very interesting and useful devices. The basic principle of these systems is too realise a force and position transformation between the...
Extended Perturbation Theory for the Local Density Distribution Function (1996)
Colombi, S., Bernardeau, F., Bouchet, F. R., Hernquist, L.
Perturbation theory makes it possible to calculate the probability distribution function (PDF) of the large scale density field in the small variance limit. For top hat smoothing and scale-free...
Self-similarity and scaling behavior of scale-free gravitational clustering (1995)
Colombi, S., Bouchet, F. R., Hernquist, L.
We measure the scaling properties of the probability distribution of the smoothed density field in $N$-body simulations of expanding universes with scale-free initial power-spectra, with particular...
Friction is present in almos every motion control application an effect the quality of the position, velocity or force control. This influence depends on the controls strategy itself and on the...
Load sensing and related control system for the articulated transporter of JET (1995)
The paper describes the "electronic" stiffening of the actuators developed for the articulated boom of JET. Experimental trials on a two joints Boom have confirmed the improvements of speed and...
A Count Probability Cookbook: Spurious Effects and the Scaling Model (1994)
Colombi, S., Bouchet, F. R., Schaeffer, R.
We study the errors brought by finite volume effects and dilution effects on the practical determination of the count probability distribution function P_N(n,L), which is the probability of having N...
Redshift Distortions of Clustering: A Lagrangian Approach (1994)
Hivon, E., Bouchet, F. R., Colombi, S., Juszkiewicz, R.
We study the effects of peculiar velocities on statistical measures of galaxy clustering. These effects occur when distances to the galaxies are estimated from their redshifts. It is assumed that the...
Perturbative Lagrangian Approach to Gravitational Instability (1994)
Bouchet, F. R., Colombi, S., Hivon, E., Juszkiewicz, R.
This paper deals with the time evolution in the matter era of perturbations in Friedman-Lemaitre models with arbitrary density parameter $\Omega$, with either a zero cosmological constant, $\Lambda =...
I propose a method to fit the probability distribution function (hereafter PDF) of the large scale density field rho, motivated by a Lagrangian version of the continuity equation. It consists in...
Hamilton, D., Colombi, S., Galbiati, L., Haist, B., Mills, S., Raimondi, T.
Ongoning remote handling trials are being performed at JET, using the MASCOT IV servomanipulator, in order to establish the feasibility of proposed remote handling tasks. This promotes the...
Compliance compensation in mechatronic systems (1994)
Compliance, or elasticity is present in many mechatronic system, e.g. when the transmission of a movement is done using steel cables, belts or elasti shafts. Also, compliance can be present in some...
First Results with the Modified Jet - the Jet Team (1994)
Adams, J. M., Agarici, Y., Ageladarakis, P., Alper, B., Altmann, H., Andrew, P., ...
JET was extensively modified in the 1992/93 shutdown. The new pumped divertor and many new systems were brought into operation early in 1994. Operations have progressed to 4MA plasma current and,...
Lymphocyte Lifespan in Murine Retrovirus-Induced Immunodeficiency (1994)
Moutschen, Michel, Colombi, S, Deprez, Marie-Claire, Greimers, Roland, Van Wijk, F, Hotermans, C, ...
Skewness Induced by Gravity (1993)
Juszkiewicz, R., Bouchet, F. R., Colombi, S.
Large-scale structures, observed today, are generally believed to have grown from random, small-amplitude inhomogeneities, present in the early Universe. We investigate how gravitational instability...
Actuators and control for teleoperators (1993)
The design of a mechatronic system in an industrial context is alwais affected by cost. Either the performances have to be optimized for a given cost or the cost must be minimized for the given...
Active Control of an Electromagnetic Suspension System (1993)
Electromagnetic suspension system are commonly used in the field of high speed vhicles, tool machines, frictionless bearings and conveyor systems. This paper compares three different control...
Improvement of transparency of Bilateral Master-Slave force reflecting servomanipulators (1993)
Colombi, S., Raimondi, T., Costi, G.
The "transparency" of a bilateral Master-Slave force reflecting servomanipulator depends on serval interconnected parameters . This paper presents some digital algorithms that can be used to ehnance...
Digital position and velocity determination in controlled drive systems (1992)
Motion control of robotic or manipulator joints, tool machines axes or more genrally of drive systems require accurate position, velocity and possibly acceleration control. Today, these controls are...
Improvement of brushless DC motor actuators (1992)
Today, the use of brushless DC motors (BDCM) in robotic applications is only at its beginning in spite of their remarkable features. This is due to the increased complexity of the control with...
Improvements of actuators in teleoperators (1991)
Colombi, S., Raimondi, T., Costi, G.
The main feature of a bilateral Master-Slave servomanipulator is its "transparency", i.e. the operatr has virtually to feel as if his own hands were extended to the Slave on the spot of remote...
Computer aided design of digital controls (1989)
This paper describes some powerful programs which are very useful for the design of digital controls. These programs work either on IBM personal computers and on VAX computers. This increases the...
This paper describes the numerical simulation of the stator currents, flux and torque controls of an AC motor. The control priciple used is based on the orientation on the rotor flux. The originality...
Numerical simulation of the stator currents, flux and torque controls of an AC motor (1989)
This paper describes a realtime digital train simulator which was realized to develop real braking devices. The main originalities of this simulator consists in the solution introduced in order to...