High energy γ-ray lines: a probe for a cold dark matter halo

1991 ◽  
Author(s):  
Pierre Salati ◽  
Pascal Chardonnet
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
High Energy ◽  
Dark Matter Halo ◽  
Γ Ray

γ-ray lines as a probe for a cold-dark-matter halo

1989 ◽  
Vol 40 (10) ◽  
pp. 3168-3186 ◽  
Author(s):  
Alain Bouquet ◽  
Pierre Salati ◽  
Joseph Silk
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
Dark Matter Halo ◽  
Γ Ray

scholarly journals Probing the structure of the cold dark matter halo using ancient mica

1998 ◽  
Vol 59 (2) ◽  
Author(s):  
Edward A. Baltz ◽  
Andrew J. Westphal ◽  
Daniel P. Snowden-Ifft
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
Dark Matter Halo

scholarly journals Crater 2: An Extremely Cold Dark Matter Halo

2017 ◽  
Vol 839 (1) ◽  
pp. 20 ◽  
Author(s):  
Nelson Caldwell ◽  
Matthew G. Walker ◽  
Mario Mateo ◽  
Edward W. Olszewski ◽  
Sergey Koposov ◽  
...  
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
Dark Matter Halo

scholarly journals New mass bound on fermionic dark matter from a combined analysis of classical dSphs

2019 ◽  
Vol 487 (4) ◽  
pp. 5711-5720 ◽  
Author(s):  
D Savchenko ◽  
A Rudakovskyi
Keyword(s):  
Dark Matter ◽  
Lower Bound ◽  
Cold Dark Matter ◽  
Pauli Exclusion Principle ◽  
Dark Matter Halo ◽  
Exclusion Principle ◽  
Fermion Mass ◽  
Density Profiles ◽  
Combined Analysis ◽  
Dwarf Spheroidal Galaxies

ABSTRACTDwarf spheroidal galaxies (dSphs) are the most compact dark-matter-dominated objects observed so far. The Pauli exclusion principle limits the number of fermionic dark matter particles that can compose a dSph halo. This results in a well-known lower bound on their particle mass. So far, such bounds were obtained from the analysis of individual dSphs. In this paper, we model dark matter halo density profiles via the semi-analytical approach and analyse the data from eight ‘classical’ dSphs assuming the same mass of dark matter fermion in each object. First, we find out that modelling of Carina dSph results in a much worse fitting quality compared to the other seven objects. From the combined analysis of the kinematic data of the remaining seven ‘classical’ dSphs, we obtain a new 2σ lower bound of m ≳ 190 eV on the dark matter fermion mass. In addition, by combining a sub-sample of four dSphs – Draco, Fornax, Leo I, and Sculptor – we conclude that 220 eV fermionic dark matter appears to be preferred over the standard cold dark matter at about the 2σ level. However, this result becomes insignificant if all seven objects are included in the analysis. Future improvement of the obtained bound requires more detailed data, both from ‘classical’ and ultra-faint dSphs.

scholarly journals Structure of Dark Matter Halo

1999 ◽  
Vol 183 ◽  
pp. 155-155
Author(s):  
Toshiyuki Fukushige ◽  
Junichiro Makino
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
Temperature Inversion ◽  
Dark Matter Halo ◽  
Temperature Structure ◽  
Galactic Halos ◽  
Dark Matter Halos ◽  
Density Profiles ◽  
Order Of Magnitude ◽  
Special Purpose Computer

We performed N-body simulation on special-purpose computer, GRAPE-4, to investigate the structure of dark matter halos (Fukushige, T. and Makino, J. 1997, ApJL, 477, L9). Universal profile proposed by Navarro, Frenk, and White (1996, ApJ, 462, 563), which has cusp with density profiles ρ ∝r−1in density profile, cannot be reproduced in the standard Cold Dark Matter (CDM) picture of hierarchical clustering. Previous claims to the contrary were based on simulations with relatively few particles, and substantial softening. We performed simulations with particle numbers an order of magnitude higher, and essentially no softening, and found that typical central density profiles are clearly steeper than ρ ∝r−1, as shown in Figure 1. In addition, we confirm the presence of a temperature inversion in the inner 5 kpc of massive galactic halos, and give a natural explanation for formation of the temperature structure.

scholarly journals Cold Dark Matter Substructure and the Heating of Galactic Disks

2003 ◽  
Vol 208 ◽  
pp. 391-392
Author(s):  
Andreea S. Font ◽  
Julio F. Navarro
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
Milky Way ◽  
Dark Matter Halo ◽  
Stellar Disk ◽  
Minor Role ◽  
Galactic Disks ◽  
Cosmological Simulations ◽  
A Minor

We investigate recent suggestions that substructure in cold dark matter (CDM) halos has potentially destructive effects on galactic disks. N-body simulations of disk/bulge models of the Milky Way, embedded in a dark matter halo with substructure similar to that found in cosmological simulations, show that tides from substructure halos play only a minor role in the dynamical heating of the stellar disk. This suggests that substructure might not preclude CDM halos from being acceptable hosts of thin stellar disks.

scholarly journals Testing dark energy models with a new sample of strong-lensing systems

2020 ◽  
Vol 498 (4) ◽  
pp. 6013-6033
Author(s):  
Mario H Amante ◽  
Juan Magaña ◽  
V Motta ◽  
Miguel A García-Aspeitia ◽  
Tomás Verdugo
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
Velocity Dispersion ◽  
Cosmological Parameters ◽  
Cosmic Acceleration ◽  
Dark Matter Halo ◽  
Measured Velocity ◽  
Strong Lensing ◽  
The Impact ◽  
Einstein Radius

ABSTRACT Inspired by a new compilation of strong-lensing systems, which consist of 204 points in the redshift range 0.0625 < zl < 0.958 for the lens and 0.196 < zs < 3.595 for the source, we constrain three models that generate a late cosmic acceleration: the ω-cold dark matter model, the Chevallier–Polarski–Linder, and the Jassal–Bagla–Padmanabhan parametrizations. Our compilation contains only those systems with early-type galaxies acting as lenses, with spectroscopically measured stellar velocity dispersions, estimated Einstein radius, and both the lens and source redshifts. We assume an axially symmetric mass distribution in the lens equation, using a correction to alleviate differences between the measured velocity dispersion (σ) and the dark matter halo velocity dispersion (σDM) as well as other systematic errors that may affect the measurements. We have considered different subsamples to constrain the cosmological parameters of each model. Additionally, we generate a mock data of SLS to asses the impact of the chosen mass profile on the accuracy of Einstein radius estimation. Our results show that cosmological constraints are very sensitive to the selected data: Some cases show convergence problems in the estimation of cosmological parameters (e.g. systems with observed distance ratio Dobs < 0.5), others show high values for the χ2 function (e.g. systems with a lens equation Dobs > 1 or high velocity dispersion σ > 276 km s−1). However, we obtained a fiduciary sample with 143 systems, which improves the constraints on each tested cosmological model.

scholarly journals Way-out to the gravitino problem in intersecting D-brane Pati–Salam models

2016 ◽  
Vol 31 (19) ◽  
pp. 1650111 ◽  
Author(s):  
Andrea Addazi ◽  
Maxim Yu Khlopov
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
High Energy ◽  
Indirect Detection ◽  
Supersymmetric Particle ◽  
Cosmological Time ◽  
Neutrino Sector ◽  
Very High Energy ◽  
Very High ◽  
Parity Breaking

We discuss the gravitino problem in the context of the exotic see-saw mechanism for neutrinos and leptogenesis, UV completed by intersecting D-branes Pati–Salam models. In the exotic see-saw model, supersymmetry is broken at high scales M[Formula: see text] 109 GeV and this seems in contradiction with gravitino bounds from inflation and baryogenesis. However, if gravitino is the lightest stable supersymmetric particle, it will not decay into other SUSY particles, avoiding the gravitino problem and providing a good cold dark matter (CDM). Gravitini are super heavy dark particles and they can be produced by non-adiabatic expansion during inflation. Intriguingly, from bounds on the correct abundance of dark matter (DM), we also constrain the neutrino sector. We set a limit on the exotic instantonic coupling of [Formula: see text] 10[Formula: see text]–10[Formula: see text]. This also sets constrains on the Calabi–Yau compactifications and on the string scale. This model strongly motivates very high energy DM indirect detection of neutrini and photons of 10[Formula: see text]–10[Formula: see text] GeV: gravitini can decay on them in a cosmological time because of soft R-parity breaking effective operators.

scholarly journals The statistical properties of Λ cold dark matter halo formation

2007 ◽  
Vol 383 (2) ◽  
pp. 546-556 ◽  
Author(s):  
Shaun Cole ◽  
John Helly ◽  
Carlos S. Frenk ◽  
Hannah Parkinson
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
Statistical Properties ◽  
Dark Matter Halo ◽  
Halo Formation
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