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In this work, we study non-parametric estimation of joint probabilities of a given set of discrete and continuous random variables from their (empirically estimated) 2D marginals, under the assumption that the joint probability could be…

Machine Learning · Computer Science 2022-03-04 Shaan ul Haque , Ajit Rajwade , Karthik S. Gurumoorthy

Langevin (stochastic differential) equations are routinely used to describe particle-laden flows. They predict Gaussian probability density functions (PDFs) of a particle's trajectory and velocity, even though experimentally observed…

Mathematical Physics · Physics 2024-03-11 Daniel Domínguez-Vázquez , Gustaaf B. Jacobs , Daniel M. Tartakovsky

Primordial non-Gaussianity of the local type induces a strong scale-dependent bias on the clustering of halos in the late-time Universe. This signature is particularly promising to provide constraints on the non-Gaussianity parameter…

Perturbation theory makes it possible to calculate the probability distribution function (PDF) of the large scale density field in the small variance limit. For top hat smoothing and scale-free Gaussian initial fluctuations, the result…

Astrophysics · Physics 2015-06-24 S. Colombi , F. Bernardeau , F. R. Bouchet , L. Hernquist

We study the effect of the non-Gaussianity induced by gravitational evolution upon the statistical properties of absorption in quasar (QSO) spectra. Using the generic hierarchical ansatz and the lognormal approximation we derive the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Dipak Munshi , Peter Coles , Matteo Viel

We investigate the effects of non-Gaussianity in the primordial density field on the reionization history. We rely on a semi-analytic method to describe the processes acting on the intergalactic medium (IGM), relating the distribution of…

Astrophysics · Physics 2010-03-26 D. Crociani , L. Moscardini , M. Viel , S. Matarrese

This article presents a rigorous analysis for efficient statistically accurate algorithms for solving the Fokker-Planck equations associated with high-dimensional nonlinear turbulent dynamical systems with conditional Gaussian structures.…

Statistics Theory · Mathematics 2017-09-19 Nan Chen , Andrew J. Majda , Xin T. Tong

State-of-the-art image-set matching techniques typically implicitly model each image-set with a Gaussian distribution. Here, we propose to go beyond these representations and model image-sets as probability distribution functions (PDFs)…

Computer Vision and Pattern Recognition · Computer Science 2015-08-03 Mehrtash Harandi , Mathieu Salzmann , Mahsa Baktashmotlagh

The behavior of the probability density function (PDF) transport equation at the limits of the probability space is studied from the point of view of fluid mechanics. Different boundary conditions are considered depending on the nature of…

Fluid Dynamics · Physics 2025-02-04 Luis Valiño , Juan Hierro

We present an analysis of the constraints on the amplitude of primordial non-Gaussianity of local type described by the dimensionless parameter $f_{\rm NL}$. These constraints are set by the auto-correlation functions (ACFs) of two large…

Cosmology and Nongalactic Astrophysics · Physics 2010-08-11 Jun-Qing Xia , Anna Bonaldi , Carlo Baccigalupi , Gianfranco De Zotti , Sabino Matarrese , Licia Verde , Matteo Viel

The statistical meaning of the local non-Gaussianity parameters f_NL and g_NL is examined in detail. Their relations to the skewness and the kurtosis of the probability distribution of density fluctuations are shown to obey simple fitting…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-22 Sirichai Chongchitnan , Joseph Silk

The velocity distributions of stellar tracers in general exhibit weak non-Gaussianity encoding information on the orbital composition of a galaxy and the underlying potential. The standard solution for measuring non-Gaussianity involves…

Astrophysics of Galaxies · Physics 2020-10-28 Jason L. Sanders , N. Wyn Evans

This Letter provides a theoretical interpretation of numerically generated probability density functions (PDFs) of intermittent plasma transport events. Specifically, nonlinear gyrokinetic simulations of ion-temperature-gradient turbulence…

Plasma Physics · Physics 2010-11-10 Johan Anderson , Pavlos Xanthopoulos

Fusing probabilistic information is a fundamental task in signal and data processing with relevance to many fields of technology and science. In this work, we investigate the fusion of multiple probability density functions (pdfs) of a…

Signal Processing · Electrical Eng. & Systems 2023-01-20 Günther Koliander , Yousef El-Laham , Petar M. Djurić , Franz Hlawatsch

This paper provides an improved flamelet/progress variable (FPV) model for the simulation of turbulent combustion, employing the statistically most likely distribution (SMLD) approach for the joint probability density function (PDF) of the…

Fluid Dynamics · Physics 2015-04-21 Alessandro Coclite , Giuseppe Pascazio , Pietro De Palma , Luigi Cutrone , Matthias Ihme

We present probability distribution functions (PDFs) of the surface densities of ionized and neutral gas in the nearby spiral galaxies M31 and M51, as well as of dust emission and extinction Av in M31. The PDFs are close to lognormal and…

Astrophysics of Galaxies · Physics 2015-06-23 Elly M. Berkhuijsen , Andrew Fletcher

The formula for probability density functions (PDFs) has been extended to include PDF for energy dissipation rates in addition to other PDFs such as for velocity fluctuations, velocity derivatives, fluid particle accelerations, energy…

Statistical Mechanics · Physics 2009-11-11 T. Arimitsu , N. Arimitsu

Probability density function (PDF) methods are a promising alternative to predicting the transport of solutes in groundwater under uncertainty. They make it possible to derive the evolution equations of the mean concentration and the…

Fluid Dynamics · Physics 2016-03-15 Lennart Schüler , Nicolae Suciu , Peter Knabner , Sabine Attinger

A $\delta N$ formalism is used to study the non-Gaussianity of the primordial curvature perturbation on an uniform density hypersurfaces generated by the warm inflation for the first time. After introducing the framework of the warm…

General Relativity and Quantum Cosmology · Physics 2016-04-01 Xiao-Min Zhang , Hong-Yang Ma , Peng-Cheng Chu , Jun-Ting Liu , Jian-Yang Zhu

Any hint of non-gaussianity in the cosmological initial conditions will provide us with a unique window into the physics of early universe. We show that the impact of a small local primordial non-gaussianity (generated on super-horizon…

Astrophysics · Physics 2008-12-18 Niayesh Afshordi , Andrew J. Tolley