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Cosmic structure simulations have improved enormously over the past decade, both in terms of the resolution which can be achieved, and with the addition of hydrodynamic and other techniques to formerly purely gravitational methods. This is…

Astrophysics · Physics 2007-05-23 H. M. P. Couchman

Numerical simulations play a key important role in modern cosmology. Examples are plenty including the cosmic web - large scale structure of the distribution of galaxies in space - which was first observed in N-body simulations and later…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-07 Anatoly Klypin , Francisco Prada , Johan Comparat

Boundary constraints in physical, environmental and engineering models restrict smooth states such as temperature to follow known physical laws at the edges of their spatio-temporal domain. Examples include fixed-state or fixed-derivative…

Methodology · Statistics 2025-12-05 Yue Ma , Oksana A. Chkrebtii , Stephen R. Niezgoda

A major aim of cosmological surveys is to test deviations from the standard $\Lambda$CDM model, but the full scientific value of these surveys will only be realised through efficient simulation methods that keep up with the increasing…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-06 Yash Gondhalekar , Sownak Bose , Baojiu Li , Carolina Cuesta-Lazaro

We present a quantum algorithm for efficiently sampling transformed Gaussian random fields on $d$-dimensional domains, based on an enhanced version of the classical moving average method. Pointwise transformations enforcing boundedness are…

Quantum Physics · Physics 2025-08-20 Matthias Deiml , Daniel Peterseim

Energy loss through optically thin radiative cooling plays an important part in the evolution of astrophysical gas dynamics and should therefore be considered a necessary element in any numerical simulation. Although the addition of this…

Instrumentation and Methods for Astrophysics · Physics 2010-11-12 Allard Jan van Marle , Rony Keppens

We conduct simulations of $\sim$kpc-scale cool clouds in the circumgalactic medium (CGM), using initial conditions sampled from a highly resolved cosmological magneto-hydrodynamical zoom-in of a Milky Way-like galaxy. We select ten distinct…

Astrophysics of Galaxies · Physics 2026-03-02 Rahul Ramesh , Dylan Nelson , Drummond Fielding , Marcus Brüggen

The conventional method of generating initial conditions for cosmological N-body simulations introduces a significant error in the real-space statistical properties of the particles. More specifically, the finite box size leads to a…

Astrophysics · Physics 2009-11-10 Edwin Sirko

Understanding of the structure evolution in the Universe has been greatly advanced with a rapid progress in high-resolution cosmological simulations. In this contribution, we report a new set of cosmological simulations with $512^3$ ($\sim…

Astrophysics · Physics 2007-05-23 Y. P. Jing , Yasushi Suto

The Gaussian Kinematic Formula (GKF, see Adler and Taylor (2007,2011)) is an extremely powerful tool allowing for explicit analytic predictions of expected values of Minkowski functionals under realistic experimental conditions for…

Instrumentation and Methods for Astrophysics · Physics 2015-03-18 Yabebal Fantaye , Frode Hansen , Davide Maino , Domenico Marinucci

We present the 'simage' software suite for the simulation of artificial extragalactic images, based empirically around real observations of the Hubble Ultra Deep Field (UDF). The simulations reproduce galaxies with realistic and complex…

Instrumentation and Methods for Astrophysics · Physics 2015-05-19 Benjamin M. Dobke , David E. Johnston , Richard Massey , F. William High , Matthew Ferry , Jason Rhodes , R. Ali Vanderveld

Reconstructing the Gaussian initial conditions at the beginning of the Universe from the survey data in a forward modeling framework is a major challenge in cosmology. This requires solving a high dimensional inverse problem with an…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-28 Chirag Modi , François Lanusse , Uroš Seljak , David N. Spergel , Laurence Perreault-Levasseur

Computations have helped elucidate the dynamics of Earth's mantle for several decades already. The numerical methods that underlie these simulations have greatly evolved within this time span, and today include dynamically changing and…

Computational Engineering, Finance, and Science · Computer Science 2017-05-09 Timo Heister , Juliane Dannberg , Rene Gassmöller , Wolfgang Bangerth

We develop an algorithm for setting up initial Gaussian random density and velocity fields containing one or more peaks or dips, in an arbitrary cosmological scenario. The intention is to generate appropriate initial conditions for…

Astrophysics · Physics 2015-06-24 Rien van de Weygaert , Edmund Bertschinger

We investigate the information on cosmology contained in Gaussianised weak gravitational lensing convergence fields. Employing Box-Cox transformations to determine optimal transformations to Gaussianity, we develop analytical models for the…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 B. Joachimi , A. N. Taylor , A. Kiessling

The last two decades have seen a major expansion in the availability, size, and precision of time-domain datasets in astronomy. Owing to their unique combination of flexibility, mathematical simplicity and comparative robustness, Gaussian…

Instrumentation and Methods for Astrophysics · Physics 2022-11-11 Suzanne Aigrain , Daniel Foreman-Mackey

We introduce Koenderink filters as novel tools for statistical cosmology. Amongst several promising applications, they provide a test for the Gaussianity of random fields. We focus on this application and present some preliminary results…

Astrophysics · Physics 2007-05-23 Jens Schmalzing

We extend field-level inference to jointly constrain the cosmological parameters $\{A,\omega_{\rm cdm},H_0\}$, in both real and redshift space. Our analyses are based on mock data generated using a perturbative forward model, with noise…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-25 Kazuyuki Akitsu , Marko Simonović , Shi-Fan Chen , Giovanni Cabass , Matias Zaldarriaga

This paper proposes a general framework for internal patch-based image restoration based on Conditional Random Fields (CRF). Unlike related models based on Markov Random Fields (MRF), our approach explicitly formulates the posterior…

Computer Vision and Pattern Recognition · Computer Science 2018-07-10 Milad Niknejad , Jose M. Bioucas-Dias , Mario A. T. Figueiredo

Computational meshes, as a way to partition space, form the basis of much of PDE simulation technology, for instance for the finite element and finite volume discretization methods. In complex simulations, we are often driven to modify an…

Mathematical Software · Computer Science 2025-06-23 Matthew G. Knepley