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Related papers: Velocity Differences as a Probe of Non--Gaussian D…

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Random fields in nature often have, to a good approximation, Gaussian characteristics. We present the mathematical framework for a new and simple method for investigating the non-Gaussian contributions, based on counting the maxima and…

Statistical Mechanics · Physics 2012-10-26 T. H. Beuman , A. M. Turner , V. Vitelli

Non-Gaussianity indicates complex dynamics related to extreme events or significant outliers. However, the correlation between non-Gaussianity and the dynamics of heterogeneous environments in anomalous diffusion remains uncertain. Inspired…

Soft Condensed Matter · Physics 2023-11-22 Haolan Xu , Xu Zheng , Xinghua Shi

We propose a method to probe higher-order correlators of the primordial density field through the inhomogeneity of local non-Gaussian parameters, such as f_NL, measured within smaller patches of the sky. Correlators between n-point…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-28 Christian T. Byrnes , Sami Nurmi , Gianmassimo Tasinato , David Wands

We study the one-point probability distribution functions (PDFs) of the peculiar velocity and the density fluctuation in a cosmological fluid. Within the perturbative approach to the structure formation scenario, the effect of ``pressure''…

Astrophysics · Physics 2009-11-11 Takayuki Tatekawa

Gaussian random fields pervade all areas of science. However, it is often the departures from Gaussianity that carry the crucial signature of the nonlinear mechanisms at the heart of diverse phenomena, ranging from structure formation in…

Statistical Mechanics · Physics 2015-06-05 T. H. Beuman , A. M. Turner , V. Vitelli

We investigate the evolution of the skewness of the distribution of density fluctuations in CDM models with both Gaussian and non--Gaussian initial fluctuations. We show that the method proposed by Coles \& Frenk (1991), which uses the…

Astrophysics · Physics 2015-06-24 P. Coles , L. Moscardini , F. Lucchin , S. Matarrese , A. Messina

We study the effect of randomly distributed diffusivities and speeds in two models for active particle dynamics with active and passive fluctuations. We demonstrate how non-Gaussian displacement distributions emerge in these models in the…

Statistical Mechanics · Physics 2023-02-01 Elisabeth Lemaitre , Igor M. Sokolov , Ralf Metzler , Aleksei V. Chechkin

We study the velocity distribution in spherical collapses and cluster-pair collisions by use of N-body simulations. Reflecting the violent gravitational processes, the velocity distribution of the resultant quasi-stationary state generally…

Astrophysics · Physics 2009-11-10 O. Iguchi , Y. Sota , T. Tatekawa , A. Nakamichi , M. Morikawa

Motivated by recent experiments reporting non-Gaussian velocity distributions in driven dilute granular materials, we study by numerical simulation the properties of 2D inelastic gases. We find theoretically that the form of the observed…

Soft Condensed Matter · Physics 2009-11-10 J. S. van Zon , F. C. MacKintosh

The Sachs-Wolfe temperature fluctuations produced by primordial density perturbations are proportional to the potential field \phi, which is a weighted integral over the density field \delta. Because of the central limit theorem, \phi can…

Astrophysics · Physics 2011-05-12 Robert J. Scherrer , Robert K. Schaefer

Non-Gaussian shapes, despite a linear form of the mean-squared displacement, have been observed for the displacement distribution in a large range of diffusive systems. Stochastic models for such "Brownian yet non-Gaussian" diffusion will…

Statistical Mechanics · Physics 2022-04-05 R. Metzler , A. V. Chechkin

In this work, we present a model-independent method to quantify the non-Gaussian fluctuations in the observable distributions, which are assessed by the difference between the measured observable distributions and reconstructed observable…

Nuclear Theory · Physics 2025-04-01 Xinyu Wang , Xiang Chen , Junping Yang , Ying Cui , Zhuxia Li , Kai Zhao , Yingxun Zhang

Multivariate spatial fields are of interest in many applications, including climate model emulation. Not only can the marginal spatial fields be subject to nonstationarity, but the dependence structure among the marginal fields and between…

Methodology · Statistics 2023-11-21 Paul F. V. Wiemann , Matthias Katzfuss

We analyze the deviations from Maxwell-Boltzmann statistics found in recent experiments studying velocity distributions in two-dimensional granular gases driven into a non-equilibrium stationary state by a strong vertical vibration. We show…

Statistical Mechanics · Physics 2009-11-07 Alain Barrat , Emmanuel Trizac

We explore the velocity distributions in a vibrated binary granular gas system, focusing on how these distributions are influenced by the coefficient of restitution (CoR) and the inelasticity of particle collisions. Through molecular…

Soft Condensed Matter · Physics 2024-10-07 Rameez Farooq Shah , Syed Rashid Ahmad

The probability density function of single-point velocity fluctuations in turbulence is studied systematically using Fourier coefficients in the energy-containing range. In ideal turbulence where energy-containing motions are random and…

Fluid Dynamics · Physics 2009-11-10 H. Mouri , M. Takaoka , A. Hori , Y. Kawashima

We numerically investigate non-Gaussianities in the late-time cosmological density field in Fourier space. We explore various statistics, including the two-point and three-point probability distribution function (PDF) of phase and modulus,…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-14 Jian Qin , Jun Pan , Yu Yu , Pengjie Zhang

We study the linear response in different models of driven granular gases. In some situations, even if the the velocity statistics can be strongly non-Gaussian, we do not observe appreciable violations of the Einstein formula for diffusion…

Statistical Mechanics · Physics 2009-11-13 A. Puglisi , A. Baldassarri , A. Vulpiani

This paper studies the scale and redshift variation of density and velocity distributions in self-gravitating collisionless dark matter flow by a halo-based non-projection approach. All particles are divided into halo and out-of-halo…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-28 Zhijie Xu

We study the dependence on configuration in momentum space of the primordial 3-point function of density perturbations in several different scenarios: standard slow-roll inflation, curvaton and variable decay models, ghost inflation, models…

Astrophysics · Physics 2009-07-09 Daniel Babich , Paolo Creminelli , Matias Zaldarriaga