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相关论文: Evolution of the Cosmological Density Distribution…

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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…

宇宙学与河外天体物理 · 物理学 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…

宇宙学与河外天体物理 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

星系天体物理 · 物理学 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…

星系天体物理 · 物理学 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…

机器学习 · 计算机科学 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…

宇宙学与河外天体物理 · 物理学 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…

流体动力学 · 物理学 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…

流体动力学 · 物理学 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…

宇宙学与河外天体物理 · 物理学 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…

宇宙学与河外天体物理 · 物理学 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.…

天体物理仪器与方法 · 物理学 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…

天体物理学 · 物理学 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…

宇宙学与河外天体物理 · 物理学 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…

宇宙学与河外天体物理 · 物理学 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…

宇宙学与河外天体物理 · 物理学 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…

高能天体物理现象 · 物理学 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,…

天体物理学 · 物理学 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…

宇宙学与河外天体物理 · 物理学 2015-03-19 Xin Wang , Mark Neyrinck , István Szapudi , Alex Szalay , Xuelei Chen , Julien Lesgourgues , Antonio Riotto , Martin Sloth