Axions as hot and cold dark matter
نویسندگان
چکیده
The presence of a hot dark matter component has been hinted at 3σ by a combination of the results from different cosmological observations. We examine a possibility that pseudo Nambu-Goldstone bosons account for both hot and cold dark matter components. We show that the QCD axions can do the job for the axion decay constant fa . O ( 1010 ) GeV, if they are produced by the saxion decay and the domain wall annihilation. We also investigate the cases of thermal QCD axions, pseudo Nambu-Goldstone bosons coupled to the standard model sector through the Higgs portal, and axions produced by modulus decay.
منابع مشابه
Dark matter in axino-gravitino cosmology.
It is suggested that the axino mass in the 1 MeV region and gravitino mass in the eV region can provide an axino lifetime of order of the time of photon decoupling. In this case, some undecayed axinos act like cold dark matters and some axino decay products (gravitinos and hot axions) act like hot dark matters at the time of galaxy formation. The cosmological constant problem and the dark matte...
متن کاملA High Resolution Search for Dark-Matter Axions
In the current concordance cosmology, 23% of the universe’s total energy density is contributed by exotic dark matter [1]. The axion, arising from the Peccei-Quinn solution to the strong CP problem [2], satisfies the two criteria necessary for cold dark matter [3]: (1) a very cold population of axions could be present in our universe in sufficient quantities to provide the required dark matter ...
متن کاملResults of a search for cold flows of dark matter axions.
Theoretical arguments predict that the distribution of cold dark matter in spiral galaxies has peaks in velocity space associated with nonthermalized flows of dark matter particles. We searched for the corresponding peaks in the spectrum of microwave photons from axion to photon conversion in a cavity detector for dark matter axions. We found none and place limits on the density of any local fl...
متن کاملExperimental Constraints on the Axion Dark Matter Halo Density
We report results from an ongoing search for cold dark matter axions using a single resonant cavity in a large magnetic field for the purposes of stimulating axion decay. Potential candidates were investigated in 750 Hz intervals over the frequency range 550≤ f ≤ 810 MHz (2.3 μeV ≤ma ≤ 3.4 μeV). From the lack of a persistent signal, we conclude that KSVZ axions contribute no more than 0.45 GeV/...
متن کاملAxion BEC Dark Matter
Cold dark matter axions thermalize through gravitational self-interactions and form a BoseEinstein condensate when the photon temperature reaches approximately 500 eV. Axion Bose-Einstein condensation provides an opportunity to distinguish axions from the other dark matter candidates on the basis of observation. The rethermalization of axions that are about to fall in a galactic potential well ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2013