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相关论文: Characterising dark matter haloes with computer vi…

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We use the recently completed one billion particle Via Lactea II LambdaCDM simulation to investigate local properties like density, mean velocity, velocity dispersion, anisotropy, orientation and shape of the velocity dispersion ellipsoid,…

Multiresolution analysis is applied to the problem of halo identification in cosmological N-body simulations. The procedure makes use of a discrete wavelet transform known as the algorithme a trous and segmentation analysis. It has the…

天体物理学 · 物理学 2009-10-31 Michael D. Seymour , Lawrence M. Widrow

We develop and test an algorithm to rescale a simulated dark-matter particle distribution or halo catalogue from a standard gravity model to that of a modified gravity model. This method is based on that of Angulo & White but with some…

宇宙学与河外天体物理 · 物理学 2015-08-18 Alexander Mead , John Peacock , Lucas Lombriser , Baojiu Li

We present analysis of the evolution of dark matter halos in dense environments of groups and clusters in dissipationless cosmological simulations. The premature destruction of halos in such environments, known as the overmerging, reduces…

天体物理学 · 物理学 2009-10-30 Anatoly Klypin , Stefan Gottloeber , Andrey Kravtsov , Alexei Khokhlov

The density profiles of dark matter haloes can potentially probe dynamics, fundamental physics, and cosmology, but some of the most promising signals reside near or beyond the virial radius. While these scales have recently become…

宇宙学与河外天体物理 · 物理学 2022-04-29 Benedikt Diemer

We present a new suite of over 1,500 cosmological N-body simulations with varied Warm Dark Matter (WDM) models ranging from 2.5 to 30 keV. We use these simulations to train Convolutional Neural Networks (CNNs) to infer WDM particle masses…

Dark matter haloes form from small perturbations to the almost homogeneous density field of the early universe. Although it is known how large these initial perturbations must be to form haloes, it is rather poorly understood how to predict…

宇宙学与河外天体物理 · 物理学 2024-02-22 Daniel López-Cano , Jens Stücker , Marcos Pellejero Ibañez , Raúl E. Angulo , Daniel Franco-Barranco

We perform for the first time high-resolution zoom-in re-simulations of individual halos in the context of the Multi-coupled Dark Energy (McDE) scenario, which is characterised by the existence of two distinct dark matter particle species…

宇宙学与河外天体物理 · 物理学 2016-02-05 E. Garaldi , M. Baldi , L. Moscardini

We perform an analysis of the Cosmic Web as a complex network, which is built on a $\Lambda$CDM cosmological simulation. For each of nodes, which are in this case dark matter halos formed in the simulation, we compute 10 network metrics,…

宇宙学与河外天体物理 · 物理学 2020-08-04 Maksym Tsizh , Bohdan Novosyadlyj , Yurij Holovatch , Noam I Libeskind

Warm dark matter (WDM) has been proposed as an alternative to cold dark matter (CDM), to resolve issues such as the apparent lack of satellites around the Milky Way. Even if WDM is not the answer to observational issues, it is essential to…

宇宙学与河外天体物理 · 物理学 2015-05-20 Lin F. Yang , Mark C. Neyrinck , Miguel A. Aragon-Calvo , Bridget Falck , Joseph Silk

Using the model for (bottom-up) hierarchical halo growth recently developed by Salvador-Sol\'e et al. (2012), we derive the typical spherically averaged density profile for haloes with several relevant masses in the concordant warm dark…

宇宙学与河外天体物理 · 物理学 2012-07-10 Jordi Viñas , Eduard Salvador-Solé , Alberto Manrique

We use explainable neural networks to connect the evolutionary history of dark matter halos with their density profiles. The network captures independent factors of variation in the density profiles within a low-dimensional representation,…

宇宙学与河外天体物理 · 物理学 2024-01-22 Luisa Lucie-Smith , Hiranya V. Peiris , Andrew Pontzen

Strong lensing provides a powerful means of investigating the nature of dark matter as it probes dark matter structure on sub-galactic scales. We present an extension of a forward modeling framework that uses flux ratios from quadruply…

宇宙学与河外天体物理 · 物理学 2019-07-30 Daniel Gilman , Simon Birrer , Tommaso Treu , Anna Nierenberg , Andrew Benson

The statistics of dark matter halos is an essential component of understanding the nonlinear evolution in modified gravity cosmology. Based on a series of modified gravity N-body simulations, we investigate the halo mass function,…

宇宙学与河外天体物理 · 物理学 2013-02-21 Youcai Zhang , Pengjie Zhang , Xiaohu Yang , Weiguang Cui

Dark matter (DM) halos form hierarchically in the Universe through a series of merger events. Cosmological simulations can represent this series of mergers as a graph-like ``tree'' structure. Previous work has shown these merger trees are…

We propose a morphological multi-scale analysis of large-scale structures obtained by computer simulations and by observations. Structures are obtained at different scales by applying a wavelet transform on the observed and simulated data.…

天体物理学 · 物理学 2007-05-23 E. Lega , A. Bijaoui , J. -M. Alimi , H. Scholl

Cosmological galaxy formation simulations are still limited by their spatial/mass resolution and cannot model from first principles some of the processes, like star formation, that are key in driving galaxy evolution. As a consequence they…

The formation of dark-matter halos from small cosmological perturbations generated in the early universe is a highly non-linear process typically modeled through N-body simulations. In this work, we explore the use of deep learning to…

宇宙学与河外天体物理 · 物理学 2026-05-07 Toka Alokda , Cristiano Porciani

The recent detection of a 3.5 keV X-ray line from the centres of galaxies and clusters by Bulbul et al. (2014a) and Boyarsky et al. (2014a) has been interpreted as emission from the decay of 7 keV sterile neutrinos which could make up the…

宇宙学与河外天体物理 · 物理学 2015-11-18 Sownak Bose , Wojciech A. Hellwing , Carlos S. Frenk , Adrian Jenkins , Mark R. Lovell , John C. Helly , Baojiu Li

We measure the mass function of dark matter halos in a large set of collisionless cosmological simulations of flat LCDM cosmology and investigate its evolution at z<~2. Halos are identified as isolated density peaks, and their masses are…