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

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We study experimentally the particle velocity fluctuations in an electrostatically driven dilute granular gas. The experimentally obtained velocity distribution functions have strong deviations from Maxwellian form in a wide range of…

Statistical Mechanics · Physics 2016-08-31 I. S. Aranson , J. S. Olafsen

We investigate the non-gaussian properties of cosmic-string-seeded linear density perturbations with cold and hot dark matter backgrounds, using high-resolution numerical simulations. We compute the one-point probability density function of…

Astrophysics · Physics 2009-10-30 P. P. Avelino , E. P. S. Shellard , J. H. P. Wu , B. Allen

Padmanabhan (1996) has suggested a model to relate the nonlinear two - point correlation function to the linear two - point correlation function. In this paper, we extend this model in two directions: (1) By averaging over the initial…

Astrophysics · Physics 2015-06-24 Dipak Munshi , T. Padmanabhan

Granular gases are commonly characterized through their velocity distribution, which provides access to the granular temperature. In experiments, velocity distributions are typically obtained by particle tracking, which however becomes…

In this work we study the simultaneous effect of primordial non-Gaussianity and the modification of the gravity in $f(R)$ framework on large scale structure observations. We show that non-Gaussianity and modified gravity introduce a scale…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-12 Nareg Mirzatuny , Shahram Khosravi , Shant Baghram , Hossein Moshafi

We study the spectrum P_\zeta and bispectrum B_\zeta of the primordial curvature perturbation \zeta when the latter is generated by scalar and vector field perturbations. The tree-level and one-loop contributions from vector field…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-23 Cesar A. Valenzuela-Toledo , Yeinzon Rodriguez , David H. Lyth

The non-Gaussian normal diffusion, i.e., the probability distribution function (PDF) is non-Gaussian but the mean squared displacement (MSD) depends on time linearly, has been observed in particle motions. Here we show by numerical…

Disordered Systems and Neural Networks · Physics 2016-04-06 Jianjin Wang , Yong Zhang , Hong Zhao

We compute in detail how deviations from Einstein gravity at the inflation energy scale could appear as non-Gaussian features in the sky. To illustrate this we use multi-field $\alpha-$attractor models in the framework of supergravity to…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-14 Nicola Bartolo , Domenico Matteo Bianco , Raul Jimenez , Sabino Matarrese , Licia Verde

The velocity distribution of galaxies in clusters is not universal; rather, galaxies are segregated according to their spectral type and relative luminosity. We examine the velocity distributions of different populations of galaxies within…

The analytical formalism to obtain the probability distribution functions (PDFs) of spherically-averaged cosmic densities and velocity divergences in the mildly non-linear regime is presented. A large-deviation principle is applied to those…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-03 Cora Uhlemann , Sandrine Codis , Oliver Hahn , Christophe Pichon , Francis Bernardeau

We study the generation of non-Gaussianity in models of hybrid inflation with two inflaton fields, (2-brid inflation). We analyse the region in the parameter and the initial condition space where a large non-Gaussianity may be generated…

Astrophysics · Physics 2010-04-30 Christian T. Byrnes , Ki-Young Choi , Lisa M. H. Hall

Recent studies unveiled the Fickian yet non-Gaussian (FNG) dynamics of many soft matter systems and suggested this phenomenon as a general characteristic of the diffusion in complex fluids. In particular, it was shown that the distribution…

Soft Condensed Matter · Physics 2018-10-24 Alejandro Cuetos , Neftalí Morillo , Alessandro Patti

We compute the probability density distribution of maxima for a scalar random field in the presence of local non-gaussianities. The physics outcome of this analysis is the following. If we focus on maxima whose curvature is larger than a…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-08 Flavio Riccardi , Marco Taoso , Alfredo Urbano

We show that the acceleration-difference of neighboring free-falling particles (= geodesic deviation) measured in the local reference frame of a GR-noninertial observer is not given by the Riemann tensor. With the gravito-electric field of…

General Relativity and Quantum Cosmology · Physics 2023-04-18 Christoph Schmid

Primordial perturbations with wavelengths greater than the observable universe shift the effective background fields in our observable patch from their global averages over the inflating space. This leads to a landscape picture where the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Sami Nurmi , Christian T. Byrnes , Gianmassimo Tasinato

We introduce a simple linear equation relating the line-of-sight peculiar velocity and density contrast correlation functions. The relation, which we call the "Gaussian cell two-point energy-like equation", is valid in the…

Astrophysics · Physics 2009-11-10 Saleem Zaroubi , Enzo Branchini

We analyze multi-field inflationary systems which yield strongly scale dependent non-Gaussianity with a shape that is very close to the local shape. As in usual multi-field models, the non-Gaussianity arises from the non-linear transfer of…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-27 Jason Kumar , Louis Leblond , Arvind Rajaraman

We address the problem of the so-called ``granular gases'', i.e. gases of massive particles in rapid movement undergoing inelastic collisions. We introduce a class of models of driven granular gases for which the stationary state is the…

Statistical Mechanics · Physics 2009-10-31 A. Puglisi , V. Loreto , U. Marini Bettolo Marconi , A. Vulpiani

We derive the distribution of particle currents for a system of interacting active Brownian particles in the long time limit using large deviation theory and a weighted many body expansion. We find the distribution is non-Gaussian, except…

Statistical Mechanics · Physics 2018-12-19 Trevor GrandPre , David T. Limmer

We consider the description of the clustering of halos for physically-motivated types of non-Gaussian initial conditions. In particular we include non-Gaussianity of the type arising from single field slow-roll, multi fields, curvaton…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Licia Verde , Sabino Matarrese