The Skeleton: Connecting Large Scale Structures to Galaxy Formation (2009)
Pichon, Christophe, Gay, Christophe, Pogosyan, Dmitry, Prunet, Simon, Sousbie, Thierry, Colombi, Stephane, ...
We report on two quantitative, morphological estimators of the filamentary structure of the Cosmic Web, the so-called global and local skeletons. The first, based on a global study of the matter...
Accurate estimators of power spectra in N-body simulations (2008)
Colombi, Stephane, Jaffe, Andrew H., Novikov, Dmitri, Pichon, Christophe
abridged] A method to rapidly estimate the Fourier power spectrum of a point distribution is presented. This method relies on a Taylor expansion of the trigonometric functions. It yields the Fourier...
Full-Sky Weak Lensing Simulation with 70 Billion Particles (2008)
Teyssier, Romain, Pires, Sandrine, Prunet, Simon, Aubert, Dominique, Pichon, Christophe, Amara, Adam, ...
We have performed a 70 billion dark-matter particles N-body simulation in a 2 $h^{-1}$ Gpc periodic box, using the concordance, cosmological model as favored by the latest WMAP3 results. We have...
Towards the optimal window for the 2MASS dipole (2007)
Chodorowski, Michal, Coiffard, Jean-Baptiste, Bilicki, Maciej, Colombi, Stephane, Ciecielag, Pawel
A comparison of the 2MASS flux dipole to the CMB dipole can serve as a method to constrain a combination of the cosmological parameter Omega_m and the luminosity bias of the 2MASS survey. For this...
Cattaneo, Andrea, Blaizot, Jérémy, Weinberg, David H., Keres, Dusan, Colombi, Stephane, Davé, Romeel, ...
Cosmic variance of weak lensing surveys in the non-Gaussian regime (2006)
Semboloni, Elisabetta, Van Waerbeke, Ludovic, Heymans, Catherine, Hamana, Takashi, Colombi, Stephane, White, Martin, ...
The results from weak gravitational lensing analyses are subject to a cosmic variance error term that has previously been estimated assuming Gaussian statistics. In this letter we address the issue...
Cattaneo, Andrea, Blaizot, Jeremy, Weinberg, David H., Colombi, Stephane, Dave, Romeel, Devriendt, Julien, ...
We compare the galaxy population of an SPH simulation to those predicted by the GalICS semi-analytic model and a stripped down version without supernova and AGN feedback. The SPH simulation and the...
Baryon Dynamics, Dark Matter Substructure, and Galaxies (2006)
Weinberg, David H., Colombi, Stephane, Davé, Romeel, Katz, Neal
By comparing a collisionless cosmological N-body simulation (DM) to an SPH simulation with the same initial conditions, we investigate the correspondence between the dark matter subhalos produced by...
Caustics in Dark Matter Haloes (2005)
Mohayaee, Roya, Colombi, Stephane, Fort, Bernard, Gavazzi, Raphael, Shandarin, Sergei, Touma, Jihad
Caustics are formally singular structures, with infinite density, that form in collisionless media. The non-negligible velocity dispersion of dark matter particles renders their density finite. We...
The origin and implications of dark matter anisotropic cosmic infall on ~L* haloes (2005)
Aubert, Dominique, Pichon, Christophe, Colombi, Stephane
We measure the anisotropy of dark matter flows on small scales in the near environment of haloes using a large set of simulations. We rely on two different approaches to quantify the anisotropy of...
Reconstruction of primordial density fields (2005)
Mohayaee, Roya, Mathis, Hugues, Colombi, Stephane, Silk, Joseph
The Monge-Ampere-Kantorovich (MAK) reconstruction is tested against cosmological N-body simulations. Using only the present mass distribution sampled with particles, and the assumption of homogeneity...
The origin and implications of dark matter anisotropic cosmic infall on ~L* haloes (2004)
Aubert, Dominique, Pichon, Christophe, Colombi, Stephane
We measure the anisotropy of dark matter flows on small scales in the near environment of haloes using a large set of simulations. We rely on two different approaches to quantify the anisotropy of...
The origin and implications of dark matter anisotropic cosmic infall on ~L* haloes (2004)
Aubert, Dominique, Pichon, Christophe, Colombi, Stephane
We measure the anisotropy of dark matter flows on small scales in the near environment of haloes using a large set of simulations. We rely on two different approaches to quantify the anisotropy of...
The origin and implications of dark matter anisotropic cosmic infall on ~L* haloes (2004)
Aubert, Dominique, Pichon, Christophe, Colombi, Stephane
We measure the anisotropy of dark matter flows on small scales in the near environment of haloes using a large set of simulations. We rely on two different approaches to quantify the anisotropy of...
The origin and implications of dark matter anisotropic cosmic infall on ~L* haloes (2004)
Aubert, Dominique, Pichon, Christophe, Colombi, Stephane
We measure the anisotropy of dark matter flows on small scales in the near environment of haloes using a large set of simulations. We rely on two different approaches to quantify the anisotropy of...
The origin and implications of dark matter anisotropic cosmic infall on ~L* haloes (2004)
Aubert, Dominique, Pichon, Christophe, Colombi, Stephane
We measure the anisotropy of dark matter flows on small scales in the near environment of haloes using a large set of simulations. We rely on two different approaches to quantify the anisotropy of...
The origin and implications of dark matter anisotropic cosmic infall on ~L* haloes (2004)
Aubert, Dominique, Pichon, Christophe, Colombi, Stephane
We measure the anisotropy of dark matter flows on small scales in the near environment of haloes using a large set of simulations. We rely on two different approaches to quantify the anisotropy of...
The origin and implications of dark matter anisotropic cosmic infall on ~L* haloes (2004)
Aubert, Dominique, Pichon, Christophe, Colombi, Stephane
We measure the anisotropy of dark matter flows on small scales in the near environment of haloes using a large set of simulations. We rely on two different approaches to quantify the anisotropy of...
The Clustering of Intergalactic Metals (2003)
Pichon, Christophe, Scannapieco, Evan, Aracil, Bastien, Petitjean, Patrick, Aubert, Dominique, Bergeron, Jacqueline, ...
We measure the spatial clustering of metals in the intergalactic medium from z = 1.7 to 3.0, as traced by 643 CIV and 104 SiIV N >= 10^12 cm^-2 absorption systems in 19 high signal-to-noise (40-80)...
Skeleton as a probe of the cosmic web: the 2D case (2003)
Novikov, Dimitri, Colombi, Stephane, Doré, Olivier
We discuss the skeleton as a probe of the filamentary structures of a 2D random field. It can be defined for a smooth field as the ensemble of pairs of field lines departing from saddle points,...
Tree structure of the percolating Universe (2000)
Colombi, Stephane, Pogosyan, Dmitry, Souradeep, Tarun
We present a numerical study of topological descriptors of initially Gaussian and scale-free density perturbations evolving via gravitational instability in an expanding universe. We carefully...
Hamana, Takashi, Colombi, Stephane, Suto, Yasushi
We examine the light-cone effect on the two-point correlation functions using numerical simulations for the first time. Specifically, we generate several sets of dark matter particle distributions on...
Numerical study of the cosmic shear (2000)
Hamana, Takashi, Colombi, Stephane, Mellier, Yannick
We study cosmic shear statistics using the ray-tracing simulation combined with a set of large $N$-body simulations. In this contribution, we first describe our method. Then we show some selected...
Non-Linear Evolution of the Bispectrum of Cosmological Perturbations (1997)
Scoccimarro, Roman, Colombi, Stephane, Fry, J. N., Frieman, Joshua A., Hivon, Eric, Melott, Adrian
The bispectrum, the three-point function of density fluctuations in Fourier space, is the lowest order statistic that carries information about the spatial coherence of large-scale structures. For...
Large Scale Structure Tests of Warm Dark Matter (1995)
Colombi, Stephane, Dodelson, Scott, Widrow, Lawrence M.
Warm dark matter (WDM) is an intriguing model of structure formation from the point of view of both cosmology and particle physics. We consider a one-parameter family of WDM models. The linear power...