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Matter evolved under influence of gravity from minuscule density fluctuations. Non-perturbative structure formed hierarchically over all scales, and developed non-Gaussian features in the Universe, known as the Cosmic Web. To fully…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-01 Siyu He , Yin Li , Yu Feng , Shirley Ho , Siamak Ravanbakhsh , Wei Chen , Barnabás Póczos

We study the ellipticity probability distribution function (PDF) of voids in redshift space with galaxies as tracers of the shapes of voids. We find that the redshift space distortion on the shape of voids statistically increases the…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-06 Masatoshi Shoji , Jounghun Lee

A new method for constructing exact inhomogeneous universes is presented, that allows variation in 3 dimensions. The resulting spacetime may be statistically uniform on average, or have random, non-repeating variation. The construction…

General Relativity and Quantum Cosmology · Physics 2012-03-19 Charles Hellaby

Cosmic variance is the intrinsic scatter in the number density of galaxies due to fluctuations in the large-scale dark matter density field. In this work, we present a simple analytic model of cosmic variance in the high redshift Universe…

Astrophysics of Galaxies · Physics 2020-10-21 A. C. Trapp , Steven R. Furlanetto

We propose a new, physically motivated fitting function for density PDFs in turbulent gas. Although it is known that when gas is isothermal, the PDF is approximately lognormal in the core, high-resolution simulations show large deviations…

Astrophysics of Galaxies · Physics 2013-07-02 Philip F. Hopkins

This paper investigates probability density functions (PDFs) that are continuous everywhere, nearly uniform around the mode of distribution, and adaptable to a variety of distribution shapes ranging from bell-shaped to rectangular. From the…

Machine Learning · Computer Science 2022-04-01 Osamu Fujita

This paper presents a general formalism that allows the derivation of the cumulant generating function and one-point Probability Distribution Function (PDF) of the aperture mass ($\hat{M}_{ap}$), a common observable for cosmic shear…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-31 Paulo Reimberg , Francis Bernardeau

Dispersion of a passive scalar from concentrated sources in fully developed turbulent channel flow is studied with the probability density function (PDF) method. The joint PDF of velocity, turbulent frequency and scalar concentration is…

Fluid Dynamics · Physics 2010-03-24 J. Bakosi , P. Franzese , Z. Boybeyi

We present and test a framework that models the three-dimensional distribution of mass in the Universe as a function of cosmological and astrophysical parameters. Our approach combines two different techniques: a rescaling algorithm that…

We discuss the generation and statistics of the density fluctuations in highly compressible polytropic turbulence, based on a simple model and one-dimensional numerical simulations. Observing that density structures tend to form in a…

Fluid Dynamics · Physics 2009-10-31 Thierry Passot , Enrique Vazquez-Semadeni

We measure the Voronoi density probability distribution function (PDF) for both dark matter and halos in N-body simulations. For the dark matter, Voronoi densities represent the matter density field smoothed on a uniform mass scale, which…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-26 Drew Jamieson , Marilena Loverde

The distribution of matter in the universe is, to first order, lognormal. Improving this approximation requires characterization of the third moment (skewness) of the log density field. Thus, using Millennium Simulation phenomenology and…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-02 Andrew Repp , István Szapudi

Many astrophysical analyses depend on estimates of redshifts (a proxy for distance) determined from photometric (i.e., imaging) data alone. Inaccurate estimates of photometric redshift uncertainties can result in large systematic errors.…

Instrumentation and Methods for Astrophysics · Physics 2022-05-31 Biprateep Dey , Jeffrey A. Newman , Brett H. Andrews , Rafael Izbicki , Ann B. Lee , David Zhao , Markus Michael Rau , Alex I. Malz

We discuss correlation properties of a general mass density field introducing a classification of structures based on their complexity. Standard cosmological models for primordial mass fluctuations are characterized by a sort of large-scale…

Astrophysics · Physics 2009-11-10 Francesco Sylos Labini , Andrea Gabrielli

The cosmic large scale structure encodes the formation and evolution of a weblike network of dark matter and galaxies within the Universe. The cosmological information is wrapped up in non-Gaussian statistics requiring characterisation…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-26 Alex Gough

An approach to cosmological modelling is presented that incorporates the inhomogeneous structure of the Cosmic Web, specifically focusing on the interplay between cosmic voids and density walls. We extend the standard homogeneous and…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-12 John Moffat

In this work we present cosmological N-body simulations of the Local Universe with initial conditions constrained by the Two-Micron Redshift Survey (2MRS) within a cubic volume of 180 Mpc/h side-length centred at the Local Group. We use a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Steffen Heß , Francisco-Shu Kitaura , Stefan Gottloeber

Recent direct measurements of Galactic cosmic ray spectra by balloon/space-borne detectors reveal spectral hardenings of all major nucleus species at rigidities of a few hundred GV. The all-sky diffuse gamma-ray emissions measured by the…

High Energy Astrophysical Phenomena · Physics 2018-03-21 Yi-Qing Guo , Qiang Yuan

Evolution of the statistical distribution of density field is investigated by means of a counts-in-cells method in a low-density cold-dark-matter simulated universe. Four theoretical distributions, i.e. the negative binomial distribution,…

Astrophysics · Physics 2015-06-24 Haruhiko Ueda , Jun'ichi Yokoyama

The matter density field exhibits a nearly lognormal probability density distribution (PDF) after entering into the nonlinear regime. Recently, it has been shown that the shape of the power spectrum of a logarithmically transformed density…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Xin Wang , Mark Neyrinck , István Szapudi , Alex Szalay , Xuelei Chen , Julien Lesgourgues , Antonio Riotto , Martin Sloth
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