Stéphane Colombi

Cosmic velocity--gravity relation in redshift space (2008)

Colombi, Stéphane, Chodorowski, Michał, Teyssier, Romain

We propose a simple way to estimate the parameter beta = Omega_m^(0.6)/b from three-dimensional galaxy surveys. Our method consists in measuring the relation between the cosmological velocity and...

Experimental Cosmic Statistics I: Variance (2007)

Stéphane Colombi, István Szapudi, Adrian Jenkins, Jörg Colberg

Counts-in-cells are measured in the CDM Virgo Hubble Volume simulation. This large N-body experiment has 10 9 particles in a cubic box of size 2000 h \Gamma1 Mpc. The unprecedented combination of...

Experimental Cosmic Statistics II: Distribution (2007)

István Szapudi, Stéphane Colombi, Adrian Jenkins, Jörg Colberg

Colombi et al. 1999 (paper I) investigated the counts-in-cells statistics and their respective errors in the CDM Virgo Hubble Volume simulation. This extremely large N-body experiment also allows a...

The 3D skeleton of the SDSS (2006)

Sousbie, Thierry, Pichon, Christophe, Courtois, Hélène, Colombi, Stéphane, Novikov, Dmitri

The length of the three-dimensional filaments observed in the fourth public data-release of the SDSS is measured using the {\em local skeleton} method. It consists in defining the set of points where...

3D Spatial Distribution of the Intergalactic Medium (2001)

Petitjean, Patrick, Rollinde, Emmanuel, Aracil, Bastien, Pichon, Christophe, Colombi, Stéphane

Very recently a new inversion method has been developped to analyze the intergalactic medium seen in absorption in quasar spectra (the so-called Lyman-alpha forest). This method is applied to recover...

Experimental Cosmic Statistics I: Variance (1999)

Colombi, Stéphane, Szapudi, István, Jenkins, Adrian, Colberg, Jörg

Counts-in-cells are measured in the $\tau$CDM Virgo Hubble Volume simulation. This large N-body experiment has 10^9 particles in a cubic box of size 2000 h^{-1} Mpc. The unprecedented combination of...

Experimental Cosmic Statistics II: Distribution (1999)

Szapudi, István, Colombi, Stéphane, Jenkins, Adrian, Colberg, Jörg

Colombi et al. 1999 (paper I) investigated the counts-in-cells statistics and their respective errors in the $\tau$CDM Virgo Hubble Volume simulation. This extremely large $N$-body experiment also...

Cosmic Error and the Statistics of Large Scale Structure (1995)

Szapudi, István, Colombi, Stéphane

We examine the errors on counts in cells extracted from galaxy surveys. The measurement error, related to the finite number of sampling cells, is disentangled from the ``cosmic error'', due to the...