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Generalized statistical models of voids and hierarchical structure in cosmology are developed. The often quoted negative binomial model and frequently used thermodynamic model are shown to be special cases of a more general distribution…

Astrophysics · Physics 2008-11-26 Aram Z. Mekjian

A theoretical framework is developed to describe the transformation that distributes probability density functions uniformly over space. In one dimension, the cumulative distribution can be used, but does not generalize to higher…

Neural and Evolutionary Computing · Computer Science 2016-09-08 Eric Kee

The viscous Cardassian cosmology is discussed, assuming that there is a bulk viscosity in the cosmic fluid. The dynamical analysis indicates that there exists a singular curve in the phase diagram of viscous Cardassian model. In the viscous…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Chang-Bo Sun , Jia-Ling Wang , Xin-Zhou Li

Perturbation theory makes it possible to calculate the probability distribution function (PDF) of the large scale density field in the small variance limit. For top hat smoothing and scale-free Gaussian initial fluctuations, the result…

Astrophysics · Physics 2015-06-24 S. Colombi , F. Bernardeau , F. R. Bouchet , L. Hernquist

Supersonic turbulence occurs in many environments, particularly in astrophysics. In the crucial case of isothermal turbulence, the probability density function (PDF) of the logarithmic density, $s$, is well measured, but a theoretical…

Astrophysics of Galaxies · Physics 2024-10-31 Evan Scannapieco , Liubin Pan , Edward Buie , Marcus Brüggen

In this work a satisfactory, simple theoretical prediction of the data corresponding to observationally (by fine tuning condition) estimated value of the cosmological constant is given. It is supposed (in conceptually analogy with…

Astrophysics · Physics 2007-12-27 Vladan Pankovic , Simo Ciganovic , Jovan Ivanovic , Rade Glavatovic , Petar Grujic

The time evolution of the probability density function (PDF) of the mass density is formulated and solved for systems in free-fall using a simple appoximate function for the collapse of a sphere. We demonstrate that a pressure-free collapse…

Astrophysics of Galaxies · Physics 2015-06-17 Philipp Girichidis , Lukas Konstandin , Anthony P. Whitworth , Ralf S. Klessen

We first established the dynamic equations to describe the noisy circling motion of a single particle and the corresponding probability conservation equation in both two dimensions and three dimensions, and then developed the evolution…

Statistical Mechanics · Physics 2012-06-07 Tieyan Si

The one-point probability distribution function (pdf) is computed for the $25\hmpc$-smoothed density field of rich clusters of galaxies in the Abell/\aco\ catalogs. The observed pdf is compared to the pdf s drawn similarly from mock…

Astrophysics · Physics 2007-05-23 Tsafrir Kolatt

In the paper we consider the macroscopic model of plasma of scalar charged particles, obtained by means of the statistical averaging of the microscopic equations of particle dynamics in a scalar field. On the basis of kinetic equations,…

General Relativity and Quantum Cosmology · Physics 2015-06-23 Yurii Ignat'ev , Alexander Agathonov , Mikhail Mikhailov , Dmitry Ignatyev

We present the first cosmological constraints derived from the analysis of the void size function. This work relies on the final BOSS DR12 data set, a large spectroscopic galaxy catalog, ideal for the identification of cosmic voids. We…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-09 Sofia Contarini , Alice Pisani , Nico Hamaus , Federico Marulli , Lauro Moscardini , Marco Baldi

Cosmography is a model-independent phenomenological approach to observational cosmology, relying on Taylor series expansions of physical quantities as a function of the cosmological redshift or other analogous variables. A recent work…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-27 C. J. A. P. Martins

The understanding of the large-scale structure formation requires the resolution of coupled nonlinear equations describing the cosmic density and velocity fields. This is a complicated problem that, for the last decade, has been essentially…

Astrophysics · Physics 2007-05-23 F. Bernardeau

We propose the use of angular fluctuations in the galaxy redshift field as a new way to extract cosmological information in the Universe. This new probe $\delta z (\hat{n})$ consists on the statistics of sky maps built by projecting…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-07 Carlos Hernandez-Monteagudo , Jonas Chaves-Montero , Raul E. Angulo

This work presents a formalism for deriving likelihoods of the cosmological density field directly from first principles within Perturbation Theory (PT). By assuming a perturbative expansion around the Gaussian initial density field and…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-30 Rodrigo Voivodic

There is empirical evidence that the two-point correlation function of the galaxy distribution follows, for small scales, reasonably well a power-law expression $\xi(r)\propto r^{-\gamma}$ with $\gamma$ between 1.5 and 1.9. Nevertheless,…

Astrophysics · Physics 2009-11-07 Martin Snethlage , Vicent J. Martinez , Dietrich Stoyan , Enn Saar

Cosmic voids in the large-scale structure of the Universe affect the peculiar motions of objects in their vicinity. Although these motions are difficult to observe directly, the clustering pattern of their surrounding tracers in redshift…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-01 Nico Hamaus , P. M. Sutter , Guilhem Lavaux , Benjamin D. Wandelt

Cosmic voids, the large underdense regions of our Universe, have emerged over the past decade as powerful cosmological laboratories: their simple dynamics, sensitivity to local gravitational effects and cosmic expansion, and ability to span…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-22 Sofia Contarini , Giovanni Verza , Alice Pisani

Using a probabilistic neural network and Lagrangian observations from the Global Drifter Program, we model the single particle transition probability density function (pdf) of ocean surface drifters. The transition pdf is represented by a…

Atmospheric and Oceanic Physics · Physics 2023-07-12 Martin T. Brolly

Fusing probabilistic information is a fundamental task in signal and data processing with relevance to many fields of technology and science. In this work, we investigate the fusion of multiple probability density functions (pdfs) of a…

Signal Processing · Electrical Eng. & Systems 2023-01-20 Günther Koliander , Yousef El-Laham , Petar M. Djurić , Franz Hlawatsch
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