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We comprehensively analyse the cosmology dependence of counts-in-cell statistics. We focus on the shape of the one-point probability distribution function (PDF) of the matter density field at mildly nonlinear scales. Based on…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-13 Cora Uhlemann , Oliver Friedrich , Francisco Villaescusa-Navarro , Arka Banerjee , Sandrine Codis

In this paper, we study the role of shear fields on the evolution of density perturbations embedded in a Friedmann flat background universe, by studying the evolution of a homogeneous ellipsoid model. In this context, we show that while the…

Astrophysics · Physics 2018-03-14 A. Del Popolo , E. N. Ercan , M. Gambera

We derive cosmological constraints from the probability distribution function (PDF) of evolved large-scale matter density fluctuations. We do this by splitting lines of sight by density based on their count of tracer galaxies, and by…

We calculate the maximum fraction of matter which is able to condense out of the expanding background universe, for any universe which will expand forever. We use a simple spherical model for the growth of density fluctuations in the…

Astrophysics · Physics 2007-05-23 Hugo Martel , Paul R. Shapiro

We conduct numerical experiments in which we systematically vary the initial density over four orders of magnitude and the turbulent velocity over a factor ten. In a companion paper, we investigate the dependence of this distribution on the…

Astrophysics of Galaxies · Physics 2018-04-04 Yueh-Ning Lee , Patrick Hennebelle

We revisit the non-sphericity of cluster-mass scale halos from cosmological N-body simulation on the basis of triaxial modelling. In order to understand the difference between the simulation results and the conventional ellipsoidal collapse…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-12 Daichi Suto , Tetsu Kitayama , Takahiro Nishimichi , Shin Sasaki , Yasushi Suto

The collapse of a rotating 3-axis ellipsoid is approximated by a system of ordinary differential equations. Violent relaxation, mass and angular momentum losses are taken into account phenomenologically. The formation of the equilibrium…

Astrophysics · Physics 2007-05-23 O. Yu. Tsupko , G. S. Bisnovatyi-Kogan

We derive a multifractal model for the velocity probability density distribution function (PDF), which is valid from the inertial range to the viscous range. The model gives a continuous evolution of velocity PDFs from large to small…

chao-dyn · Physics 2008-02-03 Jens Eggers , Z. Jane Wang

Accurate modelling of redshift-space distortions (RSD) is challenging in the non-linear regime for two-point statistics e.g. the two-point correlation function (2PCF). We take a different perspective to split the galaxy density field…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-14 Enrique Paillas , Yan-Chuan Cai , Nelson Padilla , Ariel Sánchez

An analytic approximation to the mass function for gravitationally bound objects is presented. We base on the Zel'dovich approximation to extend the Press-Schechter formalism to a nonspherical dynamical model. A simple extrapolation of that…

Astrophysics · Physics 2009-10-30 Jounghun Lee , Sergei F. Shandarin

We reconstruct the dark matter density field from spatially overlapping spectroscopic and photometric redshift catalogs through a forward modelling approach. Instead of directly inferring the underlying density field, we find the best…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-01 Benjamin Horowitz , Peter Melchior

At any given scale, 3$\times$2-point statistics extract only three numbers from the joint distribution of the cosmic matter density and galaxy density fluctuations: their variances and their covariance. It is well known that the full shape…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-07 Oliver Friedrich , Lina Castiblanco , Anik Halder , Cora Uhlemann

We present application of a highly-scalable overlapping grid-based nonconforming Schwarz-spectral element method (Schwarz-SEM) to study the dynamics of rotating ellipsoidal particles. The current study is one of the first to explore the…

Fluid Dynamics · Physics 2021-04-19 Ketan Mittal , Som Dutta , Paul Fischer

The large-scale structure is a major source of cosmological information. However, next-generation photometric galaxy surveys will only provide a distorted view of cosmic structures due to large redshift uncertainties. To address the need…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-10 Eleni Tsaprazi , Jens Jasche , Guilhem Lavaux , Florent Leclercq

One of the consequences of entering the era of precision cosmology is the widespread adoption of photometric redshift probability density functions (PDFs). Both current and future photometric surveys are expected to obtain images of…

Instrumentation and Methods for Astrophysics · Physics 2015-06-19 M. Carrasco Kind , R. J. Brunner

As a step towards a more accurate modelling of redshift-space distortions in galaxy surveys, we develop a general description of the probability distribution function of galaxy pairwise velocities within the framework of the so-called…

Cosmology and Nongalactic Astrophysics · Physics 2015-02-04 Davide Bianchi , Matteo Chiesa , Luigi Guzzo

Weak lensing measurements are starting to provide statistical maps of the distribution of matter in the universe that are increasingly precise and complementary to cosmic microwave background maps. The probability distribution (PDF)…

Astrophysics · Physics 2009-11-10 Tong-Jie Zhang , Ue-Li Pen

One way of recovering information about the initial conditions of the Universe is by measuring features of the cosmological density field which are preserved during gravitational evolution and galaxy formation. In this paper we study the…

Astrophysics · Physics 2016-08-30 Rupert A. C. Croft , Enrique Gaztanaga

In this paper, we propose a new ellipsoidal mixture model. This model is based a new probability density function belonging to the family of elliptical distributions and designed to model points spread around an ellipsoidal surface. Then,…

Methodology · Statistics 2023-09-22 Denis Brazey , Antoine Godichon-Baggioni , Bruno Portier

Intermittency in MHD turbulence has been analyzed using high resolution 2D numerical simulations. We show that the Probability Distribution Functions (PDFs) of the fluctuations of the Elsasser fields, magnetic field and velocity field…

Chaotic Dynamics · Physics 2015-06-26 L. Sorriso-Valvo , V. Carbone , P. Veltri , H. Politano , A. Pouquet
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