scholarly journals Multi-Modal Clustering Events Observed by Horizon-10T and Axion Quark Nuggets

Universe ◽  
2021 ◽  
Vol 7 (10) ◽  
pp. 384
Author(s):  
Ariel Zhitnitsky

The Horizon-10T collaboration have reported observation of Multi-Modal Events (MME) containing multiple peaks suggesting their clustering origin. These events are proven to be hard to explain in terms of conventional cosmic rays (CR). We propose that these MMEs might be result of the dark matter annihilation events within the so-called axion quark nugget (AQN) dark matter model, which was originally invented for completely different purpose to explain the observed similarity between the dark and the visible components in the Universe, i.e., ΩDM∼Ωvisible without any fitting parameters. We support this proposal by demonstrating that the observations, including the frequency of appearance, intensity, the spatial distribution, the time duration, the clustering features, and many other properties nicely match the emission characteristics of the AQN annihilation events in atmosphere. We list a number of features of the AQN events which are very distinct from conventional CR air showers. The observation (non-observation) of these features may substantiate (refute) our proposal.

2020 ◽  
Vol 35 (26) ◽  
pp. 2050161
Author(s):  
A. D. Kanfon ◽  
F. Mavoa ◽  
G. Koto N’Gobi

The dynamic study of the harmonic exponential field has been made using the statefinder diagnostic. By the use of a specific method, we find out the statefinder parameters [Formula: see text], [Formula: see text] according to the deceleration parameter and the redshift. The numerical analysis of these parameters brings out the transition between the accelerated and decelerated phases of the universe. There is also an attracting effect from the SCDM (Standard Cold Dark Matter) model toward the LCDM model ([Formula: see text]CDM). In view of the results this study allows us to classify the exponential harmonic field among the quintessential models.


1997 ◽  
Vol 12 (17) ◽  
pp. 1275-1282 ◽  
Author(s):  
M. Kawasaki ◽  
Naoshi Sugiyama ◽  
T. Yanagida

Gauge-mediated supersymmetry breaking models suggest the presence of the light gravitino with mass ~ 1 keV which can be warm dark matter in our universe. We consider large scale structure of the universe in the warm dark matter model and find that the power spectrum of the gravitino dark matter is almost the same as that of a cold dark matter at scales larger than about 1 Mpc. We also study the Ly α absorption systems which are presumed to be galaxies at high redshifts and show that the baryon density in the damped Ly α absorption systems predicted by the gravitino dark matter model is quite consistent with the present observation.


Galaxies ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 92
Author(s):  
Man Chan

Recently, many studies indicate that the GeV gamma ray excess signal from the central Milky Way can be best explained by ∼40–50 GeV dark matter annihilating via the b b ¯ channel. However, this model appears to be disfavored by the recent Fermi-LAT data for dwarf spheroidal galaxies and the constraint from synchrotron radiation. In this article, we describe a consistent picture to relieve the tensions between the dark matter annihilation model and the observations. We show that a baryonic feedback process is the key to alleviate the tensions and the ∼40–50 GeV dark matter model is still the best one to account for the GeV gamma ray excess in the Milky Way.


2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Mario A. Rodríguez-Meza

We present a model of dark matter based on scalar-tensor theory of gravity. With this scalar field dark matter model we study the non-linear evolution of the large-scale structures in the universe. The equations that govern the evolution of the scale factor of the universe are derived together with the appropriate Newtonian equations to follow the nonlinear evolution of the structures. Results are given in terms of the power spectrum that gives quantitative information on the large-scale structure formation. The initial conditions we have used are consistent with the so-called concordance ΛCDM model.


2007 ◽  
Vol 3 (S248) ◽  
pp. 450-457 ◽  
Author(s):  
S. R. Majewski

AbstractThe concordance Cold Dark Matter model for the formation of structure in the Universe, while remarkably successful at describing observations on large scales, has a number of problems on galactic scales. The Milky Way and its satellite system provide a key laboratory for exploring dark matter (DM) in this regime, but some of the most definitive tests of local DM await microarcsecond astrometry, such as will be delivered by the Space Interferometry Mission (SIM Planetquest). I discuss several tests of Galactic DM enabled by future microarcsecond astrometry.


2012 ◽  
Vol 25 (4) ◽  
pp. 561-572
Author(s):  
Jaroslav Hynecek

2016 ◽  
Vol 41 ◽  
pp. 1660133 ◽  
Author(s):  
Maxim A. Makukov ◽  
Eduard G. Mychelkin ◽  
Vladimir L. Saveliev

We revive the historically first neutrino dark matter model, but with an additional assumption that neutrinos might exist in tachyonic almost sterile states. To this end we propose a group-theoretical algorithm for the description of tachyons. The key point is that we employ a distinct tachyon Lorentz group with another (superluminal) parametrization which does not require traditional introduction of imaginary masses and negative energies, and therefore does not lead to violation of causality and unitarity. Our dark matter model represents effectively scalar tachyonic neutrino-antineutrino conglomerate. Distributed all over the universe, such fluid behaves as stable isothermal/stiff medium which produces somewhat denser regions (‘smoothed halos’) around galaxies and clusters. It is shown to be consistent with observational effects (galactic rotation curves).


2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Zexi Hu ◽  
Chengfeng Cai ◽  
Yi-Lei Tang ◽  
Zhao-Huan Yu ◽  
Hong-Hao Zhang

Abstract We propose a vector dark matter model with an exotic dark SU(2) gauge group. Two Higgs triplets are introduced to spontaneously break the symmetry. All of the dark gauge bosons become massive, and the lightest one is a viable vector DM candidate. Its stability is guaranteed by a remaining Z2 symmetry. We study the parameter space constrained by the Higgs measurement data, the dark matter relic density, and direct and indirect detection experiments. We find numerous parameter points satisfying all the constraints, and they could be further tested in future experiments. Similar methodology can be used to construct vector dark matter models from an arbitrary SO(N) gauge group.


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