scholarly journals Revisiting big-bang nucleosynthesis constraints on dark-matter annihilation

2015 ◽  
Vol 751 ◽  
pp. 246-250 ◽  
Author(s):  
Masahiro Kawasaki ◽  
Kazunori Kohri ◽  
Takeo Moroi ◽  
Yoshitaro Takaesu
Keyword(s):  
Dark Matter ◽  
Big Bang ◽  
Big Bang Nucleosynthesis ◽  
Dark Matter Annihilation

Erratum: Cosmic rays from dark matter annihilation and big-bang nucleosynthesis [Phys. Rev. D79, 083522 (2009)]

2009 ◽  
Vol 80 (2) ◽  
Author(s):  
Junji Hisano ◽  
Masahiro Kawasaki ◽  
Kazunori Kohri ◽  
Takeo Moroi ◽  
Kazunori Nakayama
Keyword(s):  
Dark Matter ◽  
Cosmic Rays ◽  
Big Bang ◽  
Big Bang Nucleosynthesis ◽  
Dark Matter Annihilation

scholarly journals Cosmic rays from dark matter annihilation and big-bang nucleosynthesis

2009 ◽  
Vol 79 (8) ◽  
Author(s):  
Junji Hisano ◽  
Masahiro Kawasaki ◽  
Kazunori Kohri ◽  
Takeo Moroi ◽  
Kazunori Nakayama
Keyword(s):  
Dark Matter ◽  
Cosmic Rays ◽  
Big Bang ◽  
Big Bang Nucleosynthesis ◽  
Dark Matter Annihilation

Positron and gamma-ray signatures of dark matter annihilation and big-bang nucleosynthesis

2009 ◽  
Vol 79 (6) ◽  
Author(s):  
Junji Hisano ◽  
Masahiro Kawasaki ◽  
Kazunori Kohri ◽  
Kazunori Nakayama
Keyword(s):  
Dark Matter ◽  
Gamma Ray ◽  
Big Bang ◽  
Big Bang Nucleosynthesis ◽  
Dark Matter Annihilation

scholarly journals Dark matter annihilation in the universe

2014 ◽  
Vol 30 ◽  
pp. 1460256 ◽  
Author(s):  
Pierre Salati
Keyword(s):  
Dark Matter ◽  
Galactic Halo ◽  
Light Element ◽  
Big Bang ◽  
Microwave Background ◽  
Dark Matter Annihilation ◽  
Element Abundances ◽  
Primordial Plasma ◽  
Relic Abundance ◽  
The Universe

The astronomical dark matter is an essential component of the Universe and yet its nature is still unresolved. It could be made of neutral and massive elementary particles which are their own antimatter partners. These dark matter species undergo mutual annihilations whose effects are briefly reviewed in this article. Dark matter annihilation plays a key role at early times as it sets the relic abundance of the particles once they have decoupled from the primordial plasma. A weak annihilation cross section naturally leads to a cosmological abundance in agreement with observations. Dark matter species subsequently annihilate — or decay — during Big Bang nucleosynthesis and could play havoc with the light element abundances unless they offer a possible solution to the 7 Li problem. They could also reionize the intergalactic medium after recombination and leave visible imprints in the cosmic microwave background. But one of the most exciting aspects of the question lies in the possibility to indirectly detect the dark matter species through the rare antimatter particles — antiprotons, positrons and antideuterons — which they produce as they currently annihilate inside the galactic halo. Finally, the effects of dark matter annihilation on stars is discussed.

scholarly journals Impact of neutrino properties and dark matter on the primordial Lithium production

2019 ◽  
Vol 28 (08) ◽  
pp. 1950065 ◽  
Author(s):  
Tahani R. Makki ◽  
Mounib F. El Eid ◽  
Grant J. Mathews
Keyword(s):  
Dark Matter ◽  
Early Universe ◽  
Nuclear Physics ◽  
Big Bang ◽  
Light Elements ◽  
Big Bang Nucleosynthesis ◽  
Chemical Potentials ◽  
The Creation ◽  
The Universe

The light elements and their isotopes were produced during standard big bang nucleosynthesis (SBBN) during the first minutes after the creation of the universe. Comparing the calculated abundances of these light species with observed abundances, it appears that all species match very well except for lithium (7Li) which is overproduced by the SBBN. This discrepancy is rather challenging for several reasons to be considered on astrophysical and on nuclear physics ground, or by invoking nonstandard assumptions which are the focus of this paper. In particular, we consider a variation of the chemical potentials of the neutrinos and their temperature. In addition, we investigated the effect of dark matter on 7Li production. We argue that including nonstandard assumptions can lead to a significant reduction of the 7Li abundance compared to that of SBBN. This aspect of lithium production in the early universe may help to resolve the outstanding cosmological lithium problem.

scholarly journals Dark matter freeze-out during matter domination

2018 ◽  
Vol 33 (29) ◽  
pp. 1850181 ◽  
Author(s):  
Saleh Hamdan ◽  
James Unwin
Keyword(s):  
Dark Matter ◽  
Energy Density ◽  
Big Bang ◽  
Big Bang Nucleosynthesis ◽  
Hubble Rate ◽  
Dark Matter Relic Density ◽  
Relic Density ◽  
The Masses ◽  
The Universe ◽  
Freeze Out

We highlight the general scenario of dark matter freeze-out while the energy density of the universe is dominated by a decoupled non-relativistic species. Decoupling during matter domination changes the freeze-out dynamics, since the Hubble rate is parametrically different for matter and radiation domination. Furthermore, for successful Big Bang Nucleosynthesis the state dominating the early universe energy density must decay, this dilutes (or repopulates) the dark matter. As a result, the masses and couplings required to reproduce the observed dark matter relic density can differ significantly from radiation-dominated freeze-out.

scholarly journals Probes for 4th Generation Constituents of Dark Atoms in Higgs Boson Studies at the LHC

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
M. Yu. Khlopov ◽  
R. M. Shibaev
Keyword(s):  
Dark Matter ◽  
Higgs Boson ◽  
Big Bang ◽  
Decay Rates ◽  
Neutral Atoms ◽  
Big Bang Nucleosynthesis ◽  
Charged Species ◽  
The Difference ◽  
The Universe ◽  
Direct Dark Matter

The nonbaryonic dark matter of the Universe can consist of new stable charged species, bound in heavy neutral “atoms” by ordinary Coulomb interaction. StableU-(anti-U)quarks of 4th generation, bound in stable colorless(U- U- U-)clusters, are captured by the primordial helium, produced in Big Bang Nucleosynthesis, thus forming neutral “atoms” of O-helium (OHe), a specific nuclear interacting dark matter that can provide solution for the puzzles of direct dark matter searches. However, the existence of the 4th generation quarks and leptons should influence the production and decay rates of Higgs boson and is ruled out by the experimental results of the Higgs boson searches at the LHC, if the Higgs boson coupling to 4th generation fermions is not suppressed. Here, we argue that the difference between the three known quark-lepton families and the 4th family can naturally lead to suppression of this coupling, relating the accelerator test for such a composite dark matter scenario to the detailed study of the production and modes of decay of the 125.5 GeV boson, discovered at the LHC.

scholarly journals THE STATUS OF NEUTRINO MASS

1998 ◽  
Vol 13 (25) ◽  
pp. 4409-4423 ◽  
Author(s):  
DAVID O. CALDWELL
Keyword(s):  
Dark Matter ◽  
Neutrino Mass ◽  
Heavy Element ◽  
Sterile Neutrino ◽  
Big Bang ◽  
Atmospheric Neutrinos ◽  
Big Bang Nucleosynthesis ◽  
Robust Solution ◽  
The Status ◽  
Mass Pattern

New experimental results, if correct, require at least one light sterile neutrino, in addition to the three active ones, to accommodate the mass differences required to explain the solar νe deficit, the anomalous μ/e ratio produced by atmospheric neutrinos, and either the candidate events for νμ→ νe (or [Formula: see text]) from the LSND experiment, or the possible need for a hot component of dark matter. This neutrino mass pattern can not only accommodate all these four requirements, but also provide a robust solution to a problem presently making heavy-element synthesis by supernovae impossible and resolve a possible discrepancy between big bang nucleosynthesis theory and observations.

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