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We analyzed the performance of a perturbation theory for nonlinear cosmological dynamics, based on the Lagrangian description of hydrodynamics. In our previous paper, we solved hydrodynamic equations for a self-gravitating fluid with…

Astrophysics · Physics 2009-11-10 Takayuki Tatekawa

The probability density function (PDF) of a global measure in a large class of highly correlated systems has been suggested to be of the same functional form. Here, we identify the analytical form of the PDF of one such measure, the order…

We investigate the form of the one-point probability distribution function (pdf) for the density field of the interstellar medium using numerical simulations that successively reduce the number of physical processes included.…

Astrophysics · Physics 2014-10-13 J. Scalo , E. Vazquez-Semadeni , D. Chappell , T. Passot

We revisit the case of fast Monte-Carlo simulations of galaxy positions for a non-gaussian field. More precisely we address the question of generating a 3D field with a given one-point function (as a log-normal one, but not only) and some…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-08 Philippe Baratta , Julien Bel , Stephane Plaszczynski , Anne Ealet

We study Spatial Logistic Gaussian Process (SLGP) models for non-parametric estimation of probability density fields using scattered samples of heterogeneous sizes. SLGPs are examined from the perspective of random measures and their…

Statistics Theory · Mathematics 2025-02-20 Athénaïs Gautier , David Ginsbourger

While learning the maximum likelihood value of parameters of an undirected graphical model is hard, modelling the posterior distribution over parameters given data is harder. Yet, undirected models are ubiquitous in computer vision and text…

Machine Learning · Computer Science 2012-07-02 Max Welling , Sridevi Parise

We have continued the development of Lagrangian, cosmological perturbation theory for the low-order correlators of the matter density field. We provide a new route to understanding how the effective field theory (EFT) of large-scale…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-16 Zvonimir Vlah , Martin White , Alejandro Aviles

We demonstrate the capabilities of probabilistic diffusion models to reduce dramatically the computational cost of expensive hydrodynamical simulations to study the relationship between observable baryonic cosmological probes and dark…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-22 Satvik Mishra , Roberto Trotta , Matteo Viel

At any given scale, 3$\times$2-point statistics extract only three numbers from the joint distribution of the cosmic matter density and galaxy density fluctuations: their variances and their covariance. It is well known that the full shape…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-07 Oliver Friedrich , Lina Castiblanco , Anik Halder , Cora Uhlemann

Modern physics simulation often involves multiple functions of interests, and traditional numerical approaches are known to be complex and computationally costly. While machine learning-based surrogate models can offer significant cost…

Machine Learning · Computer Science 2025-06-10 Da Long , Zhitong Xu , Guang Yang , Akil Narayan , Shandian Zhe

The properties of the probability distribution function of the cosmological continuous density field are studied. We present further developments and compare dynamically motivated methods to derive the PDF. One of them is based on the…

Astrophysics · Physics 2009-10-22 F. Bernardeau , L. Kofman

We present a comparison of simulation-based inference to full, field-based analytical inference in cosmological data analysis. To do so, we explore parameter inference for two cases where the information content is calculable analytically:…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-08 T. Lucas Makinen , Tom Charnock , Justin Alsing , Benjamin D. Wandelt

Key non-Gaussian properties of cosmological fields can be captured by their one-point statistics, providing a complement to two-point statistical measurements from power spectra or correlation functions. Large deviation theory can robustly…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-31 Aoife Boyle , Alexandre Barthelemy , Sandrine Codis , Cora Uhlemann , Oliver Friedrich

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…

Astrophysics of Galaxies · Physics 2013-07-02 Philip F. Hopkins

The inclusion of convection in stellar evolution models lacks realism, especially near convective-radiative interfaces. Furthermore, the interaction of convection with oscillations prevent us from accurately predicting seismic frequencies,…

Solar and Stellar Astrophysics · Physics 2025-10-31 J. Philidet , K. Belkacem

Structure formation in our Universe creates non-Gaussian random fields that will soon be observed over almost the entire sky by the Euclid satellite, the Vera-Rubin observatory, and the Square Kilometre Array. An unsolved problem is how to…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-10 Joey R. Braspenning , Elena Sellentin

We present a new analytic calculation for the redshift-space evolution of the 1-point galaxy Probability Distribution Function (PDF). The nonlinear evolution of the matter density field is treated by second-order Eulerian perturbation…

Astrophysics · Physics 2009-10-31 Peter Watts , Andrew Taylor

We present a non-perturbative calculation of the 1-point probability distribution function (PDF) for the spherically-averaged matter density field. The PDF is represented as a path integral and is evaluated using the saddle-point method. It…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-20 Mikhail M. Ivanov , Alexander A. Kaurov , Sergey Sibiryakov

A variational method is used to derive a self-consistent macro-particle model for relativistic electromagnetic kinetic plasma simulations. Extending earlier work [E. G. Evstatiev and B. A. Shadwick, J. Comput. Phys., vol. 245, pp. 376-398,…

Computational Physics · Physics 2014-04-22 A. B. Stamm , B. A. Shadwick , E. G. Evstatiev