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Related papers: Speeding up N-body simulations of modified gravity…

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N-body simulations are the most powerful method to study the non-linear evolution of large-scale structure. However, they require large amounts of computational resources, making unfeasible their direct adoption in scenarios that require…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-14 Miguel Conceição , Alberto Krone-Martins , Antonio da Silva , Ángeles Moliné

Model-independent constraints on modified gravity models hitherto exist mainly on linear scales. A recently developed formalism presented a consistent parameterisation that is valid on all scales. Using this approach, we perform…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-15 Sankarshana Srinivasan , Daniel B Thomas , Francesco Pace , Richard Battye

We use the Millennium Simulation to quantify the statistical accuracy and precision of the escape velocity technique for measuring cluster-sized halo masses at z~0.1. We show that in 3D, one can measure nearly unbiased (<4%) halo masses…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-02 Daniel Gifford , Christopher J. Miller

We consider the extent to which future imaging surveys of galaxies can distinguish between dark energy and modified gravity models for the origin of the cosmic acceleration. Dynamical dark energy models may have similar expansion rates as…

We describe the construction of an N-body simulation that mimics the true velocity and mass-density fields in a box of side 256\hmpc about the Local Group , and the production of mock catalogs that mimic in detail current catalogs of…

Astrophysics · Physics 2009-10-28 Tsafrir Kolatt , Avishai Dekel , Galit Ganon , Jeffrey Willick

High-fidelity physics simulations are powerful tools in the design and optimization of charged particle accelerators. However, the computational burden of these simulations often limits their use in practice for design optimization and…

Accelerator Physics · Physics 2020-04-15 Auralee Edelen , Nicole Neveu , Yannick Huber , Mattias Frey , Christopher Mayes , Andreas Adelmann

The effects of discreteness arising from the use of the N-body method on the accuracy of simulations of cosmological structure formation are not currently well understood. After a discussion of how the relevant discretisation parameters…

Astrophysics · Physics 2009-11-13 Michael Joyce , Bruno Marcos , Thierry Baertschiger

Within the landscape of modified theories of gravity, progress in understanding the behaviour of, and developing tests for, screening mechanisms has been hindered by the complexity of the field equations involved, which are nonlinear in…

General Relativity and Quantum Cosmology · Physics 2021-03-31 Jonathan Braden , Clare Burrage , Benjamin Elder , Daniela Saadeh

Even though Nearest Neighbor Gaussian Processes (NNGP) alleviate considerably MCMC implementation of Bayesian space-time models, they do not solve the convergence problems caused by high model dimension. Frugal alternatives such as response…

Computation · Statistics 2021-09-15 Sébastien Coube-Sisqueille , Benoît Liquet

We generalize a recently developed method for accelerated Monte Carlo calculation of path integrals to the physically relevant case of generic many-body systems. This is done by developing an analytic procedure for constructing a hierarchy…

Statistical Mechanics · Physics 2011-08-08 Aleksandar Bogojevic , Ivana Vidanovic , Antun Balaz , Aleksandar Belic

(Abridged) We describe a new iterative approach for the realization of equilibrium N-body systems for given density distributions. Our method uses elements of Schwarzschild's technique and of the made-to-measure method, but is based on a…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-20 Denis Yurin , Volker Springel

In a mean-field approximation within Kinetic Field Theory, it is possible to derive an accurate analytic expression for the power spectrum of present-day non-linear cosmic density fluctuations. It depends on the theory of gravity and the…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-13 Alexander Oestreicher , Harshda Saxena , Niklas Reinhardt , Elena Kozlikin , Johannes Dombrowski , Matthias Bartelmann

The evolution of disk galaxies in modified gravity is studied by using high-resolution N-body simulations. More specifically, we use the weak field limit of two modified gravity theories, i.e., nonlocal gravity (NLG) and…

Astrophysics of Galaxies · Physics 2020-05-28 Neda Ghafourian , Mahmood Roshan , Shahram Abbassi

We apply a halo velocity bias model, $\gamma_{f}$, within the Aemulus simulation suite for General Relativity (GR) to investigate its efficacy in identifying the signature of assembly bias and Modified Gravity (MG). In the investigation of…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-01 Yirong Wang , Zhongxu Zhai , Xiaohu Yang , Jeremy L. Tinker

We present an algorithm which is designed to allow the efficient identification and preliminary dynamical analysis of thousands of structures and substructures in large N-body simulations. First we utilise a refined density gradient system…

Astrophysics · Physics 2009-11-10 Jochen Weller , Jeremiah P Ostriker , Paul Bode , Laurie Shaw

Measuring the sum of the three active neutrino masses, $M_\nu$, is one of the most important challenges in modern cosmology. Massive neutrinos imprint characteristic signatures on several cosmological observables in particular on the…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-25 Elena Giusarma , Mauricio Reyes Hurtado , Francisco Villaescusa-Navarro , Siyu He , Shirley Ho , ChangHoon Hahn

We present two new algebraic multilevel hierarchical matrix algorithms to perform fast matrix-vector product (MVP) for $N$-body problems in $d$ dimensions, namely efficient $\mathcal{H}^2_{*}$ (fully nested algorithm, i.e., $\mathcal{H}^2$…

Numerical Analysis · Mathematics 2026-04-13 Ritesh Khan , Sivaram Ambikasaran

Discovering the mass of neutrinos is a principle goal in high energy physics and cosmology. In addition to cosmological measurements based on two-point statistics, the neutrino mass can also be estimated by observations of neutrino wakes…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-08 Derek Inman , J. D. Emberson , Ue-Li Pen , Alban Farchi , Hao-Ran Yu , Joachim Harnois-Deraps

We present an approach for the inclusion of non-spherical constituents in high-resolution N-body discrete element method (DEM) simulations. We use aggregates composed of bonded spheres to model non-spherical components. Though the method…

Earth and Planetary Astrophysics · Physics 2023-11-21 Julian C. Marohnic , Joseph V. DeMartini , Derek C. Richardson , Yun Zhang , Kevin J. Walsh

We introduce $\texttt{Hi-COLA}$, a code designed to run fast, approximate $\textit{N}$-body simulations of non-linear structure formation in reduced Horndeski gravity. Given an input Lagrangian, $\texttt{Hi-COLA}$ dynamically constructs the…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-24 Bill S. Wright , Ashim Sen Gupta , Tessa Baker , Georgios Valogiannis , Bartolomeo Fiorini