Results 31 to 40 of about 555,829 (322)
Doublet-Singlet Oscillations and Dark Matter Neutrinos [PDF]
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
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
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]
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
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
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
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]
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
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]
33pp., 16+ figures not included (available by mail), SCIPP-92 ...
Jon A. Holtzman+3 more
openaire +3 more sources