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The recently proposed non-Gaussian Mat\'{e}rn random field models, generated through Stochastic Partial differential equations (SPDEs), are extended by considering the class of Generalized Hyperbolic processes as noise forcings. The models…

Applications · Statistics 2013-07-25 David Bolin , Jonas Wallin

We consider the 2D acoustic system with the Gaussian pulse as the initial data. This case was proposed at the first Workshop on benchmark problems in computational aeroacoustics, and it is commonly used for the verification of numerical…

Numerical Analysis · Mathematics 2024-04-17 Pavel Bakhvalov

We revisit the stochastic, or noise, contributions to the galaxy density field within the effective field theory (EFT) of large-scale structure. Starting from the general, all-order expression of the EFT partition function, we elucidate how…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-10 Henrique Rubira , Fabian Schmidt

Mathematical models for complex systems under random fluctuations often certain uncertain parameters. However, quantifying model uncertainty for a stochastic differential equation with an $\alpha$-stable L\'evy process is still lacking.…

Dynamical Systems · Mathematics 2021-02-24 Yayun Zheng , Fang Yang , Jinqiao Duan , Jürgen Kurths

Evolution and abundance of the large-scale structures we observe today, such as clusters of galaxies, is sensitive to the statistical properties of dark matter primordial density fluctuations, which is assumed to follow a Gaussian…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-29 Ziad Sakr , Damien Houguenague , Alain Blanchard

Large entropy fluctuations in a nonequilibrium steady state of classical mechanics were studied in extensive numerical experiments on a simple 2-freedom model with the so-called Gauss time-reversible thermostat. The local fluctuations (on a…

Chaotic Dynamics · Physics 2009-10-31 Boris Chirikov

We will in this paper report on suggestive similarities between density fluctuation power versus wavenumber on small (mm) and large (Mpc) scales. The small scale measurements were made in fusion plasmas and compared to predictions from…

Plasma Physics · Physics 2016-12-28 N. P. Basse

Cluster analysis faces two problems in high dimensions: first, the `curse of dimensionality' that can lead to overfitting and poor generalization performance; and second, the sheer time taken for conventional algorithms to process large…

Quantitative Methods · Quantitative Biology 2013-09-12 Shabnam N. Kadir , Dan F. M. Goodman , Kenneth D. Harris

We consider a general d-dimensional quantum system of non-interacting particles, with suitable statistics, in a very large (formally infinite) container. We prove that, in equilibrium, the fluctuations in the density of particles in a…

Mathematical Physics · Physics 2007-05-23 Joel L. Lebowitz , Marco Lenci , Herbert Spohn

We use numerical simulations of a (480 Mpc/h)^3 volume to show that the distribution of peak heights in maps of the temperature fluctuations from the kinematic and thermal Sunyaev-Zeldovich effects will be highly non-Gaussian, and very…

Astrophysics · Physics 2009-11-06 Naoki Yoshida , Ravi K. Sheth , Antonaldo Diaferio

The probability distribution function (PDF) of the mass surface density is an essential characteristic of the structure of molecular clouds or the interstellar medium in general. Observations of the PDF of molecular clouds indicate a…

Astrophysics of Galaxies · Physics 2015-06-18 Joerg Fischera

The spatial curvature of the universe is not yet known. Even though at present the Universe is very close to being essentially flat and most signatures of curvature appear to have been diluted by inflation, if the number of e-foldings…

High Energy Physics - Theory · Physics 2021-12-23 Sebastian Cespedes , Senarath de Alwis , Francesco Muia , Fernando Quevedo

The halo mass function, encoding the comoving number density of dark matter halos of a given mass, plays a key role in understanding the formation and evolution of galaxies. As such, it is a key goal of current and future deep optical…

Astrophysics of Galaxies · Physics 2018-03-14 Steven G. Murray , Aaron S. G. Robotham , Chris Power

Gaussian cosmic microwave background skies are fully specified by the power spectrum. The conventional method of characterizing non-Gaussian skies is to evaluate higher order moments, the n-point functions and their Fourier transforms. We…

Astrophysics · Physics 2011-05-10 Pedro G. Ferreira , Joao Magueijo

Modeling complex physical systems such as they arise in civil engineering applications requires finding a trade-off between physical fidelity and practicality. Consequently, deviations of simulation from measurements are ubiquitous even…

Computational Engineering, Finance, and Science · Computer Science 2026-03-18 Paolo Villani , Daniel Andrés Arcones , Jörg F. Unger , Martin Weiser

We have developed a method for calculating the two-point correlation function of nonlinearly evolved mass and collapsed halos in the Press-Schechter formalism. The nonlinear gravitational interaction is treated as the sum of various…

Astrophysics · Physics 2009-10-28 HongGuang BI , Li-Zhi FANG

We present the Multiscale non-Gaussian Segmentation (MnGSeg) analysis technique. This wavelet based method combines the analysis of the probability distribution function (PDF) of map fluctuations as a function of spatial scales and the…

Astrophysics of Galaxies · Physics 2019-08-07 J. -F. Robitaille , F. Motte , N. Schneider , D. Elia , S. Bontemps

Perturbation Theory (PT) applied to a cosmological density field with Gaussian initial fluctuations suggests a specific hierarchy for the correlation functions when the variance is small. In particular quantitative predictions have been…

Astrophysics · Physics 2009-10-30 D. Munshi , F. Bernardeau , A. L. Melott , R. Schaeffer

An implicit Euler finite-volume scheme for a nonlocal cross-diffusion system on the multidimensional torus is analyzed. The equations describe the dynamics of population species with repulsive or attractive interactions. The numerical…

Numerical Analysis · Mathematics 2026-01-06 Ansgar Jüngel , Panchi Li , Zhiwei Sun

We study non-Gaussianity, the spectral index of primordial scalar fluctuations and tensor modes in models where fluctuations from the inflaton and the curvaton can both contribute to the present cosmic density fluctuations. Even though…

Astrophysics · Physics 2008-11-26 Kazuhide Ichikawa , Teruaki Suyama , Tomo Takahashi , Masahide Yamaguchi
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