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We study the quasilinear evolution of the one-point probability density functions (PDFs) of the smoothed density and velocity fields in a cosmological gravitating system beginning with Gaussian initial fluctuations. Our analytic results are…

Astrophysics · Physics 2009-10-22 Lev Kofman , Edmund Bertschinger , James M. Gelb , Adi Nusser , Avishai Dekel

We test tree-level perturbation theory for Gaussian initial conditions with power spectra $P(k)\propto k^n$ by comparing the probability distribution function (PDF) for the density predicted by the Local Lagrangian Approximation (LLA) with…

Astrophysics · Physics 2015-06-24 Zacharias A. M. Protogeros , Adrian L. Melott , Robert J. Scherrer

Understanding $\textit{galaxy bias}$ -- that is the statistical relation between matter and galaxies -- is of key importance for extracting cosmological information from galaxy surveys. While the bias function $f$ -- that is the probability…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-05 Jens Stücker , Marcos Pellejero-Ibáñez , Rodrigo Voivodic , Raul E. Angulo

We calculate the one-point probability distribution function (PDF) for cosmic density in non-linear regime of the gravitational evolution. Under the local approximation that the evolution of cosmic fluid fields can be characterized by the…

Astrophysics · Physics 2009-11-10 Yasuhiro Ohta , Issha Kayo , Atsushi Taruya

We present a comparative analysis of several methods, known as local Lagrangian approximations, which are aimed to the description of the nonlinear evolution of large-scale structure. We have investigated various aspects of these…

Astrophysics · Physics 2009-11-06 Martin Makler , Takeshi Kodama , Mauricio O. Calvao

Many applications of Gaussian random fields and Gaussian random processes are limited by the computational complexity of evaluating the probability density function, which involves inverting the relevant covariance matrix. In this work, we…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-26 Theodor Bjorkmo , M. C. David Marsh

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

We present a general framework to treat the evolution of one-point probability distribution function (PDF) for cosmic density $\delta$ and velocity-divergence fields $\theta$. In particular, we derive an evolution equation for the one-point…

Astrophysics · Physics 2009-11-07 Yasuhiro Ohta , Issha Kayo , Atsushi Taruya

We compare different nonlinear approximations to gravitational clustering in the weakly nonlinear regime, using as a comparative statistic the evolution of non-Gaussianity which can be characterised by a set of numbers $S_p$ describing…

Astrophysics · Physics 2009-10-22 Dipak Munshi , Varun Sahni , Alexei A. Starobinsky

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

We discuss various analytical approximation methods for the evolution of the density fluctuation in the Universe. From primordial density fluctuation, the large-scale structure is formed via its own self-gravitational instability. For this…

Astrophysics · Physics 2007-05-23 Takayuki Tatekawa

A key obstacle to developing a satisfying theory of galaxy evolution is the difficulty in extending analytic descriptions of early structure formation into full nonlinearity, the regime in which galaxy growth occurs. Extant techniques,…

The gravitational evolution of the cosmic one-point probability distribution function (PDF) has been estimated using an analytic approximation that combines gravitational perturbation theory with the Edgeworth expansion around a Gaussian…

Astrophysics · Physics 2009-10-31 E. Gaztanaga , P. Fosalba , E. Elizalde

The gravitational evolution of the cosmic one-point Probability Distribution Function (PDF) can be estimated using an analytic approximation that combines gravitational Perturbation Theory (PT) with the Edgeworth expansion around a Gaussian…

Astrophysics · Physics 2007-05-23 P. Fosalba , E. Gaztanaga , E. Elizalde

By summarizing and extending the Lagrangian densities of the general relativity and the Kibble's gauge theory of gravitation,a further generalized Lagrangian density for a gravitational system is obtained and analyzed in greater detail,…

General Physics · Physics 2009-11-13 Fang-Pei Chen

This paper compares the continuum evolution for density equation modelling and the Gaussian mixture model on the 2D phase space long-term density propagation problem in the context of high-altitude and high area-to-mass ratio satellite…

Numerical Analysis · Mathematics 2022-05-09 Pan Sun , Camilla Colombo , Mirko Trisolini , Shuang Li

The evolution of probability distribution functions (PDFs) of continuous density, velocity and velocity derivatives ( deformation tensor) fields in the theory of cosmological gravitational instability are considered. We show that in the…

Astrophysics · Physics 2007-05-23 Lev Kofman

Gravitational lensing allows to quantify the angular distribution of the convergence field around clusters of galaxies to constrain their connectivity to the cosmic web. We describe in this paper the corresponding theory in Lagrangian space…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-20 Sandrine Codis , Raphael Gavazzi , Christophe Pichon , Celine Gouin

The non-Gaussian distribution of primordial perturbations has the potential to reveal the physical processes at work in the very early Universe. Local models provide a well-defined class of non-Gaussian distributions that arise naturally…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 David Wands

Deriving exact density functions for Gibbs point processes has been challenging due to their general intractability, stemming from the intractability of their normalising constants/partition functions. This paper offers a solution to this…

Probability · Mathematics 2024-06-12 Ottmar Cronie
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