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Related papers: A new approach to simulating collisionless dark ma…

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For problems in astrophysics, planetary science and beyond, numerical simulations are often limited to simulating fewer particles than in the real system. To model collisions, the simulated particles (aka superparticles) need to be inflated…

Earth and Planetary Astrophysics · Physics 2020-06-03 David Nesvorny , Andrew N. Youdin , Raphael Marschall , Derek C. Richardson

We use numerical simulations of critically-closed cold dark matter (CDM) models to study the effects of numerical resolution on observable quantities. We study simulations with up to $256^3$ particles using the particle-mesh (PM) method and…

Astrophysics · Physics 2009-10-22 James M. Gelb , Edmund Bertschinger

Previous studies using numerical simulations have demonstrated that the shape of the cosmic web can be described by studying the Lagrangian displacement field. We extend these analyses, showing that it is now possible to perform a…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-28 Florent Leclercq , Jens Jasche , Guilhem Lavaux , Benjamin Wandelt , Will Percival

We study the phase-space structure of a dark-matter halo formed in a high resolution simulation of a Lambda CDM cosmology. Our goal is to quantify how much substructure is left over from the inhomogeneous growth of the halo, and how it may…

Astrophysics · Physics 2009-09-25 Amina Helmi , Simon D. M. White , Volker Springel

A new method is presented for mesoscopic simulations of particle dispersions in nematic liquid crystal solvents. It allows efficient first-principle simulations of the dispersions involving many particles with many-body interactions…

Soft Condensed Matter · Physics 2009-11-07 Ryoichi Yamamoto

Dark Matter (DM) direct detection experiments usually assume the simplest possible 'Standard Halo Model' for the Milky Way (MW) halo in which the velocity distribution is Maxwellian. This model assumes that the MW halo is an isotropic,…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-02 Mattia Fornasa , Anne M. Green

We present a new self-consistent method for incorporating dark matter annihilation feedback (DMAF) in cosmological N-body simulations. The power generated by DMAF is evaluated at each dark matter (DM) particle which allows for flexible…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-23 Florian List , Nikolas Iwanus , Pascal J. Elahi , Geraint F. Lewis

Particle methods are a ubiquitous tool for solving the Vlasov-Poisson equation in comoving coordinates, which is used to model the gravitational evolution of dark matter in an expanding universe. However, these methods are known to produce…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-12 Andrew Myers , Phillip Colella , Brian Van Straalen

Probabilistic denoising diffusion models (DDMs) have set a new standard for 2D image generation. Extending DDMs for 3D content creation is an active field of research. Here, we propose TetraDiffusion, a diffusion model that operates on a…

Computer Vision and Pattern Recognition · Computer Science 2024-08-12 Nikolai Kalischek , Torben Peters , Jan D. Wegner , Konrad Schindler

An adpative integration technique for time advancement of particle motion in the context of coupled computational fluid dynamics (CFD) - discrete element method (DEM) simulations is presented in this work. CFD-DEM models provide an accurate…

Computational Physics · Physics 2018-02-28 Hariswaran Sitaraman , Ray Grout

An advanced Volume of Fluid (VOF) method is presented that enables performant three-dimensional Direct Numerical Simulations (DNS) of the interaction of two immiscible fluids in a gaseous environment with large topology changes, e.g.,…

Fluid Dynamics · Physics 2023-11-08 Johanna Potyka , Kathrin Schulte

Recent developments for mathematical modeling and numerical simulation of biomolecular systems raise new demands for qualified, stable, and efficient surface meshing, especially in implicit-solvent modeling. In our former work, we have…

Numerical Analysis · Mathematics 2016-11-11 Tiantian Liu , Minxin Chen , Benzhuo Lu

Advancements in the synthesis of faceted nanoparticles and colloids have spurred interest in the phase behavior of polyhedral shapes. Regular tetrahedra have attracted particular attention because they prefer local symmetries that are…

Soft Condensed Matter · Physics 2011-11-24 Amir Haji-Akbari , Michael Engel , Sharon C. Glotzer

We explore the dynamical restrictions on the structure of dark matter halos through a study of cosmological self-similar gravitational collapse solutions. A fluid approach to the collisionless dynamics of dark matter is developed and the…

Astrophysics · Physics 2009-10-31 Kandaswamy Subramanian

Collider events with multi-stage cascade decays fill out the kinematically allowed region in phase space with a density that is enhanced at the boundary. The boundary encodes all available information about the spectrum and is well…

High Energy Physics - Phenomenology · Physics 2017-03-08 Baris Altunkaynak , Can Kilic , Matthew D. Klimek

A numerical method based upon the immersed boundary technique for the fluid-solid coupling and on a soft-sphere approach for solid-solid contact is used to perform direct numerical simulation of the flow-induced motion of a thick bed of…

Fluid Dynamics · Physics 2014-10-01 Aman G. Kidanemariam , Markus Uhlmann

Particle acceleration in collisionless plasma systems is a central question in astroplasma and astroparticle physics. The structure of the acceleration regions, electron-ion energy equilibration, preacceleration of particles at shocks to…

High Energy Astrophysical Phenomena · Physics 2020-02-19 Martin Pohl , Masahiro Hoshino , Jacek Niemiec

We adopt the conduction fluid approximation to model the steady-state distribution of matter around a massive black hole at the center of a weakly collisional cluster of particles. By "`weakly collisional" we mean a cluster in which the…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-04 Stuart L. Shapiro , Vasileios Paschalidis

This work expands on our recently introduced low Mach enthalpy method [1] for simulating the melting and solidification of a phase change material (PCM) alongside (or without) an ambient gas phase. The method captures PCM's volume change…

Fluid Dynamics · Physics 2025-03-11 Ramakrishnan Thirumalaisamy , Amneet Pal Singh Bhalla

A method for following fragmentation simulations further in time using smoothed particle hydrodynamics (SPH) is presented. In a normal SPH simulation of the collapse and fragmentation of a molecular cloud, high-density regions of gas that…

Astrophysics · Physics 2015-06-24 M. R. Bate , I. A. Bonnell , N. M. Price