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Surrogate models have shown to be an extremely efficient aid in solving engineering problems that require repeated evaluations of an expensive computational model. They are built by sparsely evaluating the costly original model and have…

Machine Learning · Statistics 2022-12-01 M. Moustapha , B. Sudret

Muscle health is a critical component of overall health and quality of life. However, current measures of skeletal muscle health take limited account of microstructural variations within muscle, which play a crucial role in mediating muscle…

Medical Physics · Physics 2023-06-21 Noel Naughton , Stacey Cahoon , Brad Sutton , John G. Georgiadis

We train a machine learning algorithm to learn cosmological structure formation from N-body simulations. The algorithm infers the relationship between the initial conditions and the final dark matter haloes, without the need to introduce…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-02 Luisa Lucie-Smith , Hiranya V. Peiris , Andrew Pontzen , Michelle Lochner

We model the coagulation and fragmentation of dust grains during the protostellar collapse with our newly developed shark code. It solves the gas-dust hydrodynamics in a spherical geometry and the coagulation/fragmentation equation. It also…

Astrophysics of Galaxies · Physics 2022-11-16 Ugo Lebreuilly , Valentin Vallucci-Goy , Vincent Guillet , Maxime Lombart , Pierre Marchand

The set-up of the initial conditions in cosmological N-body simulations is usually implemented by rescaling the desired low-redshift linear power spectrum to the required starting redshift consistently with the Newtonian evolution of the…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-18 Matteo Zennaro , Julien Bel , Francisco Villaescusa-Navarro , Carmelita Carbone , Emiliano Sefusatti , Luigi Guzzo

Cosmological emulators of observables such as the Cosmic Microwave Background (CMB) spectra and matter power spectra commonly use training data sampled from a Latin hypercube. This method often incurs high computational costs by covering…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-03 Andreas Nygaard , Emil Brinch Holm , Steen Hannestad , Thomas Tram

HEALPix -- the Hierarchical Equal Area iso-Latitude Pixelization -- is a versatile data structure with an associated library of computational algorithms and visualization software that supports fast scientific applications executable…

Astrophysics · Physics 2011-05-05 K. M. Gorski , E. Hivon , A. J. Banday , B. D. Wandelt , F. K. Hansen , M. Reinecke , M. Bartelman

The structural and dynamic properties of the dark matter halos, though an important ingredient in understanding large-scale structure formation, require more conservative particle resolution than those required by halo mass alone in a…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-23 Sujatha Ramakrishnan , Premvijay Velmani

Understanding structure-property relations is essential to optimally design materials for specific applications. Two-scale simulations are often employed to analyze the effect of the microstructure on a component's macroscopic properties.…

Computational Engineering, Finance, and Science · Computer Science 2022-10-25 Theron Guo , Francesco A. B. Silva , Ondřej Rokoš , Karen Veroy

In this paper, we investigate the use of a mass lumped fully explicit time stepping scheme for the discretisation of the wave equation with underlying material parameters that vary at arbitrarily fine scales. We combine the leapfrog scheme…

Numerical Analysis · Mathematics 2021-09-08 Sjoerd Geevers , Roland Maier

An adaptive multi grid approach to simulating the formation of structure from collisionless dark matter is described. MLAPM (Multi-Level Adaptive Particle Mesh) is one of the most efficient serial codes available on the cosmological…

We present a new method to calculate formation of cosmological structure in the Newtonian limit. The method is based on Lagrangian perturbation theory plus two key theoretical extensions. One advance involves identifying and fixing a…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-15 Sharvari Nadkarni-Ghosh , David F. Chernoff

In this work, we derive particle schemes, based on micro-macro decomposition, for linear kinetic equations in the diffusion limit. Due to the particle approximation of the micro part, a splitting between the transport and the collision part…

Numerical Analysis · Mathematics 2017-01-19 Anaïs Crestetto , Nicolas Crouseilles , Mohammed Lemou

We present the GEOMAX algorithm and its Python implementation for a two-step compression of bispectrum measurements. The first step groups bispectra by the geometric properties of their arguments; the second step then maximises the Fisher…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-06 Davide Gualdi , Héctor Gil-Marín , Marc Manera , Benjamin Joachimi , Ofer Lahav

Multiscale systems are ubiquitous in science and technology, but are notoriously challenging to simulate as short spatiotemporal scales must be appropriately linked to emergent bulk physics. When expensive high-dimensional dynamical systems…

Machine Learning · Computer Science 2025-12-30 Quercus Hernandez , Max Win , Thomas C. O'Connor , Paulo E. Arratia , Nathaniel Trask

We present a parameter-free variant of the halo model that significantly improves the precision of matter clustering predictions, particularly in the challenging 1-halo to 2-halo transition regime, where standard halo models often fail.…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-18 Samuel Brieden , Florian Beutler , Marcos Pellejero-Ibañez

Within the framework of computational plasticity, recent advances show that the quasi-static response of an elasto-plastic structure under cyclic loadings may exhibit a time multiscale behaviour. In particular, the system response can be…

Computational Engineering, Finance, and Science · Computer Science 2023-08-25 Sebastian Rodriguez , Angelo Pasquale , Khanh Nguyen , Amine Ammar , Francisco Chinesta

Upcoming galaxy surveys will allow us to probe the growth of the cosmic large-scale structure with improved sensitivity compared to current missions, and will also map larger areas of the sky. This means that in addition to the increased…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-31 Matteo Martinelli , Roohi Dalal , Fereshteh Majidi , Yashar Akrami , Stefano Camera , Elena Sellentin

We use cosmography to present constraints on the kinematics of the Universe without postulating any underlying theoretical model a priori. To this end, we use a Markov Chain Monte Carlo analysis to perform comparisons to the supernova Ia…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-18 Alejandro Aviles , Christine Gruber , Orlando Luongo , Hernando Quevedo

$N$-body simulation serves as a critical method for modeling cosmic evolution and poses a significant challenge in high-performance computing. We present CUBE2, an open-source cosmological $N$-body code emphasizing memory efficiency,…

Instrumentation and Methods for Astrophysics · Physics 2026-03-05 Hao-Ran Yu , Bing-Hang Chen , Kun Xu , Ming-Jie Sheng , Jiaxin Han , Yipeng Jing , Huahua Cui
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