Axions as a model of Dark Matter (original) (raw)

Journal of Student Research

The true nature of dark matter is an extremely important and fundamental problem in the study of astrophysics, particle physics, cosmology and many other areas within the study of physics. This paper presents experimental evidence for the existence of dark matter through discussing the experimental results of mass profiling a galaxy and gravitational lensing. The fundamental properties of dark matter are then discussed, and evidence for these properties is presented. This allows further discussion of one of the most promising models of dark matter - the axion. The purpose of this paper is to present the evidence for the axion model, describe the nature of the theoretical axion particle, and to highlight the effects this model would have on other theories in physics such as solving the Strong CP Problem in the theory of quantum chromodynamics.

Dark matter axions revisited

Physical Review D, 2009

We study for what specific values of the theoretical parameters the axion can form the totality of cold dark matter. We examine the allowed axion parameter region in the light of recent data collected by the WMAP5 mission plus baryon acoustic oscillations and supernovae, and assume an inflationary scenario and standard cosmology. If the Peccei-Quinn symmetry is restored after inflation, we recover the usual relation between axion mass and density, so that an axion mass ma=67±2μeV makes the axion 100% of the cold dark matter. If the Peccei-Quinn symmetry is broken during inflation, the axion can instead be 100% of the cold dark matter for ma<15meV provided a specific value of the initial misalignment angle θi is chosen in correspondence to a given value of its mass ma. Large values of the Peccei-Quinn symmetry breaking scale correspond to small, perhaps uncomfortably small, values of the initial misalignment angle θi.

Cold Dark Matter Axion - A New Mass Window from Cosmological Bounds

ArXiv, 2024

Based upon a previous axion mass proposal and detection scheme, as well as considering the axion mass ranges suggested by cogent simulations in recent years, we present a revised axion/ALP search strategy and our calculations, concentrating on a narrow axion mass (and corresponding Compton frequency) window in this report. The window comprises the spectral region of 18.99 to 19.01GHz (that falls within the Ku microwave band), with a center frequency of 19.00GHz (+0.1GHz), with equivalence to am axion mass range of 78.6 to 79.6 eV, with the center mass at the value of 78.582 (+5.0) eV, our suggested most likely value for an axionic/ALP field mass, if these fields exist. Our search strategy, as summarized herewith, is based upon the assumption that the dark matter that exists in the current epoch of our physical universe is dominated by axions and thus the local observable axion density is the density of the light cold dark matter, permeating our local neighborhood (mainly in the Milky Way galactic halo). Some ideas and the design of an experiment, built around a Josephson Parametric Amplifier and Resonant Tunneling Diode combo installed in a resonant RF cavity, are also introduced in this report.

Searches for Astrophysical and Cosmological Axions

Annual Review of Nuclear and Particle Science, 2006

▪ The axion, a favored dark matter candidate, is expected to have a very small mass and extraordinarily weak couplings. Although it has eluded discovery or exclusion for three decades, it remains the most compelling solution to the strong-CP problem. Axions may be detected by their resonant conversion to RF photons in a microwave cavity permeated by a magnetic field. Experiments have already set significant limits on the axion's mass and photon coupling; progress in photon detection schemes at or below the standard quantum limit will soon enable definitive searches. Similarly, axions produced in the solar burning core may be detectable by their conversion to X rays in a magnetic helioscope. Significant improvements in both mass range and sensitivity of the axion helioscope will likewise be forthcoming in the next few years.

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