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We study the growth of structures in modified gravity models where the Poisson equation and the relationship between the two Newtonian potentials are modified by explicit functions of space and time. This parameterisation applies to the…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-24 Philippe Brax , Patrick Valageas

In engineering design, surrogate models are widely employed to replace computationally expensive simulations by leveraging design variables and geometric parameters from computer-aided design (CAD) models. However, these models often lose…

Machine Learning · Computer Science 2024-06-05 Jangseop Park , Namwoo Kang

We implement a spatially fixed mesh refinement under spherical symmetry for the characteristic formulation of General Relativity. The Courant-Friedrich-Levy (CFL) condition lets us deploy an adaptive resolution in (retarded-like) time, even…

General Relativity and Quantum Cosmology · Physics 2017-07-27 W. Barreto , H. P. de Oliveira , B. Rodriguez-Mueller

We describe and test a new version of the adaptive mesh refinement (AMR) cosmological code MASCLET. The new version of the code includes all the ingredients of its previous version plus a description of the evolution of the magnetic field…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-15 Vicent Quilis , José Ma. Martí , Susana Planelles

In this paper, we develop the residual based a posteriori error estimates and the corresponding adaptive mesh refinement algorithm for atomistic/continuum (a/c) coupling with finite range interactions in two dimensions. We have…

Numerical Analysis · Mathematics 2018-07-02 Mingjie Liao , Ping Lin , Lei Zhang

We present MG-GLAM, a code developed for the very fast production of full $N$-body cosmological simulations in modified gravity (MG) models. We describe the implementation, numerical tests and first results of a large suite of cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-13 Cheng-Zong Ruan , César Hernández-Aguayo , Baojiu Li , Christian Arnold , Carlton M. Baugh , Anatoly Klypin , Francisco Prada

In this review we present a thoroughly comprehensive survey of recent work on modified theories of gravity and their cosmological consequences. Amongst other things, we cover General Relativity, Scalar-Tensor, Einstein-Aether, and Bimetric…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Timothy Clifton , Pedro G. Ferreira , Antonio Padilla , Constantinos Skordis

Accurate calibration of gravity adaptation zones is of great significance in fields such as underwater navigation, geophysical exploration, and marine engineering. With the increasing application of gravity field data in these areas,…

Machine Learning · Computer Science 2024-10-08 Chen Yu

We introduce a cosmological model based on the normal branch of DGP braneworld gravity with a smooth dark energy component on the brane. The expansion history in this model is identical to LambdaCDM, thus evading all geometric constraints…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-02 Fabian Schmidt

We have extended Cosmos++, a multi-dimensional unstructured adaptive mesh code for solving the covariant Newtonian and general relativistic radiation magnetohydrodynamic (MHD) equations, to accommodate both discrete finite volume and…

Instrumentation and Methods for Astrophysics · Physics 2017-08-23 Peter Anninos , Colton Bryant , P. Chris Fragile , A. Miguel Holgado , Cheuk Lau , Daniel Nemergut

We present a convolutional neural network to classify distinct cosmological scenarios based on the statistically similar weak-lensing maps they generate. Modified gravity (MG) models that include massive neutrinos can mimic the standard…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-17 Austin Peel , Florian Lalande , Jean-Luc Starck , Valeria Pettorino , Julian Merten , Carlo Giocoli , Massimo Meneghetti , Marco Baldi

We systematically validate the static local mesh refinement capabilities of a recently proposed IMEX-DG scheme implemented in the framework of the deal.II library. Non-conforming meshes are employed in atmospheric flow simulations to…

Atmospheric and Oceanic Physics · Physics 2025-08-27 Giuseppe Orlando , Tommaso Benacchio , Luca Bonaventura

High-resolution simulations of particle-based kinetic plasma models typically require a high number of particles and thus often become computationally intractable. This is exacerbated in multi-query simulations, where the problem depends on…

Numerical Analysis · Mathematics 2023-07-10 Jan S. Hesthaven , Cecilia Pagliantini , Nicolò Ripamonti

We extend the scale-dependent Gaussian Streaming Model (GSM) to produce analytical predictions for the anisotropic redshift-space correlation function for biased tracers in modified gravity models. Employing the Convolution Lagrangian…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-03 Georgios Valogiannis , Rachel Bean , Alejandro Aviles

A machine-learnable variational scheme using Gaussian radial basis functions (GRBFs) is presented and used to approximate linear problems on bounded and unbounded domains. In contrast to standard mesh-free methods, which use GRBFs to…

Numerical Analysis · Mathematics 2024-10-10 Jonas A. Actor , Anthony Gruber , Eric C. Cyr , Nathaniel Trask

Recent and upcoming experimental data as well as the possibility of rich phenomenology have spiked interest in studying the quantum effects in cosmology at low (inflation-era) energy scales. One of the approaches to find covariant quantum…

General Relativity and Quantum Cosmology · Physics 2020-07-28 Sandeep Aashish

Extended Theories of Gravity with additional scalar degrees of freedom have recently acquired increasing interest due to the presence of a screening mechanism that allows suppressing at small scales (e.g., the Solar System scale) every…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-09 Enrico Laudato , Vincenzo Salzano , Keiichi Umetsu

This paper presents a comparative analysis of algorithmic strategies for fitting tessellation models to 3D image data of materials such as polycrystals and foams. In this steadily advancing field, we review and assess optimization-based…

Computer Vision and Pattern Recognition · Computer Science 2025-07-22 Andreas Alpers , Orkun Furat , Christian Jung , Matthias Neumann , Claudia Redenbach , Aigerim Saken , Volker Schmidt

Gaussian processes are used in many machine learning applications that rely on uncertainty quantification. Recently, computational tools for working with these models in geometric settings, such as when inputs lie on a Riemannian manifold,…

Machine Learning · Statistics 2023-10-31 Paul Rosa , Viacheslav Borovitskiy , Alexander Terenin , Judith Rousseau

We employ Gaussian process (GP) regression to adjust for systematic errors in D3-type dispersion corrections introducing the associated, statistically improved model D3-GP. We generated a data set containing interaction energies for 1,248…

Chemical Physics · Physics 2019-12-03 Jonny Proppe , Stefan Gugler , Markus Reiher