Results 31 to 40 of about 28,541 (177)
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
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Hot new early dark energy: Towards a unified dark sector of neutrinos, dark energy and dark matter
Hot new early dark energy describes a supercooled, first-order phase transition that takes place at sub-eV temperatures in the dark sector. It lowers the sound horizon, which provides a possible solution to the Hubble tension, and, at the same time, it ...
Florian Niedermann, Martin S. Sloth
doaj
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
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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
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The universal lower bound of the ratio of shear viscosity to entropy density is suggested by the string theory and gauge duality for any matter. We examined the ratio of shear viscosity to entropy density for viscous accretion flow towards a central ...
Sandip Dutta, Ritabrata Biswas
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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
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Structure Formation with Cold plus Hot Dark Matter [PDF]
33pp., 16+ figures not included (available by mail), SCIPP-92 ...
Jon A. Holtzman+3 more
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Improved Hot Dark Matter Bound on the QCD Axion
6+8 pages, 7 ...
Alessio Notari+2 more
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Cosmological Effects of Quantum Vacuum Condensates
In quantum field theory, many phenomena are characterized by a condensed structure of their vacua. Such a structure is responsible of a non trivial vacuum energy. Here we analyze disparate systems and we show that the thermal vacuum state for hot plasmas,
Antonio Capolupo
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Saxion cosmology for thermalized gravitino dark matter
In all supersymmetric theories, gravitinos, with mass suppressed by the Planck scale, are an obvious candidate for dark matter; but if gravitinos ever reached thermal equilibrium, such dark matter is apparently either too abundant or too hot, and is ...
Raymond T. Co+3 more
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