Results 31 to 40 of about 555,829 (322)

Doublet-Singlet Oscillations and Dark Matter Neutrinos [PDF]

open access: yes, 1996
We examine the `singlet majoron model' first introduced by Chikashige, Mohapatra and Peccei as a simple extension of the standard model with massive Majorana neutrinos.
Okada, Nobuchika
core   +2 more sources

Expanding Culturomics from Gut to Extreme Environmental Settings

open access: yesmSystems, 2021
With the advent of metagenomics, a quest began to identify the dynamics of the microbial communities in different ecological niches. Altogether, this has resulted in identification of microorganisms but is limited to only a small number of phylogenetic ...
Utkarsh Sood, Roshan Kumar, Princy Hira
doaj   +1 more source

Cosmological axion and neutrino mass constraints from Planck 2015 temperature and polarization data

open access: yesPhysics Letters B, 2016
Axions currently provide the most compelling solution to the strong CP problem. These particles may be copiously produced in the early universe, including via thermal processes.
Eleonora Di Valentino   +5 more
doaj   +1 more source

Majorana neutrinos as the dark matters in the cold plus hot dark matter model [PDF]

open access: yesPhysics Letters B, 1996
A simple model of the Majorana neutrino with the see-saw mechanism is studied, assuming that two light neutrinos are the hot dark matters with equal mass of 2.4 eV in the cold plus hot dark matter model of cosmology. We find that the heavy neutrino, which is the see-saw partner with the remaining one light neutrino, can be the cold dark matter, if the ...
Shin Sasaki   +2 more
openaire   +3 more sources

Dark Matter Caustics [PDF]

open access: yes, 2008
Caustics are a generic feature of the nonlinear growth of structure in the dark matter distribution. If the dark matter were absolutely cold, its mass density would diverge at caustics, and the integrated annihilation probability would also diverge for ...
Alard   +23 more
core   +1 more source

Cosmological Simulation for Fuzzy Dark Matter Model

open access: yesFrontiers in Astronomy and Space Sciences, 2019
Fuzzy Dark Matter (FDM), motivated by string theory, has recently become a hot candidate for dark matter. The rest mass of FDM is believed to be ~10−22eV and the corresponding de-Broglie wave length is ~1kpc. Therefore, the quantum effect of FDM plays an
Jiajun Zhang, Hantao Liu, Ming-Chung Chu
doaj   +1 more source

Squeezing the Axion

open access: yesThe Open Journal of Astrophysics, 2021
We apply the squeezed state formalism to scalar field dark matter (e.g. axion) perturbations generated during inflation. As for the inflationary perturbations, the scalar field state becomes highly squeezed as modes exit the horizon. For as long as $H>m_\
Jondalar L. J. Kuß, David J. E. Marsh
doaj   +1 more source

Neutrinos as Hot or Warm Dark Matter [PDF]

open access: yes, 2011
Both active and sterile sub-eV neutrinos can serve for hot dark matter (DM). On the other hand, keV sterile neutrinos could be a good candidate for warm DM. The beta-decaying (e.g., H-3 and Ru-106) and EC-decaying (e.g., Ho-163) nuclei are considered as the most promising targets to capture those extremely low energy neutrinos and antineutrinos ...
Zhi-zhong Xing, Y.F. Li
openaire   +2 more sources

Sterile neutrino dark matter in left-right theories

open access: yesJournal of High Energy Physics, 2020
SU(2) L × SU(2) R gauge symmetry requires three right-handed neutrinos (N i ), one of which, N 1, can be sufficiently stable to be dark matter. In the early universe, W R exchange with the Standard Model thermal bath keeps the right-handed neutrinos in ...
Jeff A. Dror   +3 more
doaj   +1 more source

Structure Formation with Cold plus Hot Dark Matter [PDF]

open access: yesThe Astrophysical Journal, 1993
33pp., 16+ figures not included (available by mail), SCIPP-92 ...
Jon A. Holtzman   +3 more
openaire   +3 more sources

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