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Related papers: Tailoring triaxial N-body models via a novel made-…

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We use the Made-to-Measure method to construct N-body realizations of self-similar, triaxial ellipsoidal halos having cosmologically realistic density profiles. Our implementation parallels previous work with a few numerical refinements,…

Astrophysics of Galaxies · Physics 2015-06-23 J. C. Malvido , J. A. Sellwood

We describe an algorithm for constructing N-body realisations of equilibrium stellar systems. The algorithm complements existing orbit-based modelling techniques using linear programming or other optimization algorithms. The equilibria are…

Astrophysics · Physics 2015-06-24 D. Syer , S. Tremaine

The parallel code NMAGIC is an implementation of a particle-based method to create made-to-measure models in agreement with observations of galaxies. It works by slowly correcting the particle weights of an evolving N-body system, until a…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-30 Lucia Morganti , Ortwin Gerhard

(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

An iterative approach is used to construct spherically symmetric equilibrium models with an anisotropic velocity distribution. The potentialities of the method have been tested on models with known distribution functions, the…

Astrophysics · Physics 2009-11-13 N. Ya. Sotnikova , S. A. Rodionov

We describe a semi-analytic model to predict the triaxial shapes of dark matter halos utilizing the sequences of random merging events captured in merger trees to follow the evolution of each halo's energy tensor. When coupled with a simple…

Astrophysics of Galaxies · Physics 2026-03-18 Paul Menker , Andrew J. Benson

We present a new high-resolution N-body algorithm for cosmological simulations. The algorithm employs a traditional particle-mesh technique on a cubic grid and successive multilevel relaxations on the finer meshes, introduced recursively in…

Astrophysics · Physics 2009-10-30 Andrey V. Kravtsov , Anatoly A. Klypin , Alexei M. Khokhlov

The three body problem is a special case of the n body problem where one takes the initial positions and velocities of three point masses and attempts to predict their motion over time according to Newtonian laws of motion and universal…

Machine Learning · Computer Science 2021-01-22 Pratyush Kumar , Aishwarya Das , Debayan Gupta

Numerous previous studies have investigated the phenomenon wherein initially spherical N-body systems are distorted to triaxial shapes. We report on an investigation of a previously described orbital instability that should oppose…

Astrophysics of Galaxies · Physics 2018-04-25 Eric I. Barnes , Evan Dowling

Gas-poor galaxies can be modelled as composite collisionless stellar systems, with a dark matter halo and one or more stellar components, representing different stellar populations. The dynamical evolution of such composite systems is often…

Astrophysics of Galaxies · Physics 2021-03-24 Carlo Nipoti , Giacomo Cherchi , Giuliano Iorio , Francesco Calura

Aims: We aim to develop an algorithm for constructing equilibrium initial conditions for simulations of disk galaxies with a triaxial halo and/or a gaseous component. This will pave the way for N-body simulations of realistic disk galaxies.…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-16 S. A. Rodionov , E. Athanassoula

We present a technique for constructing equilibrium triaxial N-body haloes with nearly arbitrary density profiles, axial ratios and spin parameters. The method is based on the way in which structures form in hierarchical cosmological…

Astrophysics · Physics 2009-11-10 Ben Moore , Stelios Kazantzidis , Juerg Diemand , Joachim Stadel

We present an efficient method for building equilibrium multi-component galaxies with non-spherical haloes and bulges. The gist of our approach is to tailor the velocity ellipsoid directly to the geometry of the mass distribution. Thus we…

Astrophysics · Physics 2009-11-06 C. M. Boily , P. Kroupa , J. Penarrubia-Garrido

We enhance the Syer & Tremaine made-to-measure (M2M) particle method of stellar dynamical modelling to model simultaneously both kinematic data and absorption line strength data thus creating a `chemo-M2M' modelling scheme. We apply the…

Astrophysics of Galaxies · Physics 2016-12-14 Richard Long

This research proposes a novel adjustable algorithm for reconstructing 3D body shapes from front and side silhouettes. Most recent silhouette-based approaches use a deep neural network trained by silhouettes and key points to estimate the…

Computer Vision and Pattern Recognition · Computer Science 2023-01-03 Aref Hemati , Azam Bastanfard

We present a novel method for including the impact of massive neutrinos in cold dark matter N-body simulations. Our approach is compatible with widely employed Newtonian N-body codes and relies on only three simple modifications. First, we…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-05 Pol Heuschling , Christian Partmann , Christian Fidler

Reshaping accurate and realistic 3D human bodies from anthropometric parameters (e.g., height, chest size, etc.) poses a fundamental challenge for person identification, online shopping and virtual reality. Existing approaches for creating…

Computer Vision and Pattern Recognition · Computer Science 2021-04-06 Yanhong Zeng , Jianlong Fu , Hongyang Chao

N-body simulations are essential for understanding the formation and evolution of structure in the Universe. However, the discrete nature of these simulations affects their accuracy when modelling collisionless systems. We introduce a new…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-18 Oliver Hahn , Raul E. Angulo

We present a framework for general relativistic N-body simulations in the regime of weak gravitational fields. In this approach, Einstein's equations are expanded in terms of metric perturbations about a Friedmann-Lema\^itre background,…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-18 Julian Adamek , Ruth Durrer , Martin Kunz

We describe an algorithm for constructing N-body realizations of equilibrium spherical systems. A general form for the mass density rho(r) is used, making it possible to represent most of the popular density profiles found in the…

Astrophysics · Physics 2009-11-10 Stelios Kazantzidis , John Magorrian , Ben Moore
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