English
Related papers

Related papers: Caustic Rings and Cold Dark Matter

200 papers

The Cold Dark Matter paradigm successfully explains many phenomena on scales larger than galaxies, but seems to predict galaxy halos which are more centrally concentrated and have a lumpier substructure than observed. Endowing cosmic dark…

Astrophysics · Physics 2007-05-23 Craig J. Hogan

We interpret the recent gravitational lensing observations of Jee et al. \cite{Jee} as first evidence for a {\it caustic} ring of dark matter in a galaxy cluster. A caustic ring unavoidably forms when a cold collisionless flow falls with…

Astrophysics · Physics 2009-05-22 V. Onemli , P. Sikivie

The collisionless cold dark matter (CCDM) model predicts overly dense cores in dark matter halos and overly abundant subhalos. We show that the idea that CDM are decaying superheavy particles which produce ultra-high energy cosmic rays with…

Astrophysics · Physics 2009-11-10 Chung-Hsien Chou , Kin-Wang Ng

The standard cold dark matter (CDM) model predicts too many and too dense small structures. We consider an alternative model that the dark matter undergoes two-body decays with cosmological lifetime $\tau$ into only one type of massive…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-04 Dalong Cheng , M. -C. Chu , Jiayu Tang

The galaxy correlation function serves as a fundamental tool for studying cosmology, galaxy formation, and the nature of dark matter. It is well established that more massive, redder and more compact galaxies tend to have stronger…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-27 Ziwen Zhang , Yangyao Chen , Yu Rong , Huiyuan Wang , Houjun Mo , Xiong Luo , Hao Li

Dark matter density is formally infinite at the location of caustic surfaces, where dark matter sheet folds in phase space. The caustics separate multi-stream regions with different number of streams. Volume elements change the parity by…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-03 Segei F. Shandarin

In this proceeding, we briefly review three recent results. First, we show that halos formed in simulations with gas cooling are significantly rounder than halos formed in dissipationless $N$-body simulations. The increase in principle axis…

Astrophysics · Physics 2016-11-03 Andrew R. Zentner , Savvas M. Koushiappas , Stelios Kazantzidis

We compare the structure and substructure of dark matter halos in model universes dominated by collisional, strongly self interacting dark matter (SIDM) and collisionless, weakly interacting dark matter (CDM). While SIDM virialised halos…

Astrophysics · Physics 2010-12-09 Ben Moore , Sergio Gelato , Adrian Jenkins , F. R. Pearce , Vicent Quilis

Gravitational lensing by the dual cusp catastrophes of the cold dark matter (CDM) caustic rings at cosmological distances may provide the tantalizing opportunity to detect CDM indirectly, and discriminate between axions and weakly…

Astrophysics · Physics 2007-08-21 V. K. Onemli

N-body simulations of Cold Dark Matter (CDM) have shown that, in this hierarchical structure formation model, dark matter halo properties, such as the density profile, the phase-space density profile, the distribution of axial ratio, the…

Astrophysics · Physics 2015-05-13 Jie Wang , Simon D. M. White

Warm Dark Matter (WDM) cosmologies are a viable alternative to the Cold Dark Matter (CDM) scenario. Unfortunately, an accurate scrutiny of the WDM predictions with N-body simulations has proven difficult due to numerical artefacts. Here, we…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Raul E. Angulo , Oliver Hahn , Tom Abel

Most of the mass content of dark matter haloes is expected to be in the form of tidal debris. The density of debris is not constant, but rather can grow due to formation of caustics at the apocenters and pericenters of the orbit, or decay…

Astrophysics · Physics 2010-04-15 Niayesh Afshordi , Roya Mohayaee , Edmund Bertschinger

The possibility of dark matter being a dissipative component represents an option for the standard view where cold dark matter (CDM) particles behave on large scales as an ideal fluid. By including a physical mechanism to the dark matter…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-13 Hermano Velten , Thiago R. P. Caramês , Júlio C. Fabris , Luciano Casarini , Ronaldo C. Batista

This work develops and explores a quantum-based theory which enables the nature and origin of cold dark matter (CDM) to be understood without need to introduce exotic particles. The quantum approach predicts the existence of certain…

Astrophysics · Physics 2009-03-02 A. D. Ernest

We develop a theoretical framework for describing the hierarchical structure of the phase space of cold dark matter haloes, due to gravitationally bound substructures. Because it includes the full hierarchy of the cold dark matter initial…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Niayesh Afshordi , Roya Mohayaee , Edmund Bertschinger

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

Warm dark matter (WDM) is an intriguing model of structure formation from the point of view of both cosmology and particle physics. We consider a one-parameter family of WDM models. The linear power spectra for these models is calculated…

Astrophysics · Physics 2010-11-30 Stephane Colombi , Scott Dodelson , Lawrence M. Widrow

Recent high-resolution simulations that include Cold Dark Matter (CDM) and baryons have shown that baryonic physics can dramatically alter the dark matter structure of galaxies. These results modify our predictions for observed galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-30 Alyson Brooks

We present a detailed non-spherical modeling of dark matter halos on the basis of a careful analysis of state-of-the art N-body simulations. The fitting formulae presented here form a complete and accurate description of the triaxial…

Astrophysics · Physics 2007-05-23 Y. P. Jing

High-quality optical rotation curves for a sample of low-luminosity spirals evidence that the dark halos around galaxies are inconsistent with the output of proper CDM simulations. In fact, dark halos enveloping stellar disks are structures…

Astrophysics · Physics 2009-11-06 P. Salucci , A. Borriello