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We develop a non-perturbative method to derive the probability distribution $P(\delta_R)$ of the density contrast within spherical cells in the quasi-linear regime. Indeed, since this corresponds to a rare-event limit a steepest-descent…

Astrophysics · Physics 2009-11-06 P. Valageas

Weak gravitational lensing surveys are rapidly becoming important tools to probe directly the mass density fluctuations in the universe and its background dynamics. Earlier studies have shown that it is possible to model the statistics of…

Astrophysics · Physics 2009-11-07 Patrick Valageas , Andrew J. Barber , Dipak Munshi

We present in this article an analysis of some of the properties of the density field realized in numerical simulations for power-law initial power-spectra in the case of a critical density universe. We compare our numerical results in the…

Astrophysics · Physics 2009-10-31 P. Valageas , C. Lacey , R. Schaeffer

We carry out N-body simulations of several non-Gaussian structure formation models, including Peebles' isocurvature cold dark matter model, cosmic string models, and a model with primordial voids. We compare the evolution of the cluster…

Astrophysics · Physics 2009-10-31 James Robinson , Jonathan E. Baker

The population of rich galaxy clusters evolves much more rapidly in a universe with critical density than one with low density, thus offering the possibility of determining the cosmological density parameter, Omega_0. We quantify this…

Astrophysics · Physics 2015-06-24 Vincent R. Eke , Shaun Cole , Carlos S. Frenk

Using a non-perturbative method developed in a previous work (paper II), we derive the probability distribution $P(\delta_R)$ of the density contrast within spherical cells in the quasi-linear regime for some non-Gaussian initial…

Astrophysics · Physics 2009-11-06 P. Valageas

Using a non-perturbative method developed in a previous article (paper II) we investigate the tails of the probability distribution $P(\rho_R)$ of the overdensity within spherical cells. We show that our results for the low-density tail of…

Astrophysics · Physics 2009-11-06 P. Valageas

We studied the spherical collapse model in the flat $\Lambda$CDM cosmology and provided exact and analytical formulaes for the calculation of the two important parameters in the application of Press-Schechter theory, the critical density…

Astrophysics · Physics 2007-05-23 Ding-fang Zeng , Yi-hong Gao

The one-point probability distribution function (pdf) of the large-scale density field is an important tool to follow the evolution of cosmological structures. In this paper we present a new model for this pdf for all regimes and all…

Astrophysics · Physics 2009-11-10 Patrick Valageas , Dipak Munshi

The adhesion model has been proposed in the past as an improvement of the Zel'dovich approximation, providing a good description of the formation of the cosmic web. We recast the model as a field theory for cosmological large scale…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Gerasimos Rigopoulos

In recent years, important progress has been made in the field of two-dimensional statistical physics. One of the most striking achievements is the proof of the Cardy-Smirnov formula. This theorem, together with the introduction of…

Probability · Mathematics 2013-06-10 Vincent Beffara , Hugo Duminil-Copin

We calculate the cosmological evolution of the 1-point probability distribution function (PDF), using an analytic approximation that combines gravitational perturbation theory with the Edgeworth expansion of the PDF. Our method applies…

Astrophysics · Physics 2009-10-22 R. Juszkiewicz , D. Weinberg , P. Amsterdamski , M. Chodorowski , F. Bouchet

Weak lensing convergence can be used directly to map and probe the dark mass distribution in the universe. Building on earlier studies, we recall how the statistics of the convergence field are related to the statistics of the underlying…

Astrophysics · Physics 2009-11-07 Andrew J. Barber , Dipak Munshi , Patrick Valageas

We present a self-consistent approach to the modeling of X-ray clusters of galaxies in a flat universe. Employing the Press and Schechter (1974) formalism to derive the mass function and relating the observable properties of clusters to…

Astrophysics · Physics 2016-08-30 J. Oukbir , J. G. Bartlett , A. Blanchard

Modelling the build-up of halos is important for linking the formation of galaxies with cosmological models. A simple model of halo growth is provided by Press-Schechter (PS) theory, where the initial field of density fluctuations is…

Astrophysics · Physics 2009-11-06 Will J. Percival

An inside-out model for the formation of haloes in a hierarchical clustering scenario is studied. The method combines the picture of the spherical infall model and a modification of the extended Press-Schechter theory. The mass accretion…

Astrophysics · Physics 2009-11-07 Nicos Hiotelis

The local Universe provides a unique opportunity for testing cosmology and theories of structure formation. To facilitate this opportunity we present a new method for the reconstruction of the quasi-linear matter density and velocity fields…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-11 Yehuda Hoffman , Edoardo Carlesi , Daniel Pomarède , Hélène M. Courtois , Stefan Gottlöber , Noam I. Libeskind , Jenny G. Sorce , Gustavo Yepes

In the context of count-in-cells statistics, the joint probability distribution of the density in two concentric spherical shells is predicted from first first principle for sigmas of the order of one. The agreement with simulation is found…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Francis Bernardeau , Sandrine Codis , Christophe Pichon

A semi-analytic model is proposed that couples the Press-Schechter formalism for the number of galaxies with a prescription for galaxy-galaxy interactions that enables to follow the evolution of galaxy morphologies along the Hubble…

Astrophysics · Physics 2009-11-07 Christophe Balland , Julien E. G. Devriendt , Joe Silk

This paper presents a stochastic approach to the clustering evolution of dark matter haloes in the Universe. Haloes, identified by a Press-Schechter-type algorithm in Lagrangian space, are described in terms of `counting fields', acting as…

Astrophysics · Physics 2009-10-30 P. Catelan , F. Lucchin , S. Matarrese , C. Porciani
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