相关论文: Evolution and thermalization of dark matter axions…
The axions produced during the QCD phase transition by vacuum realignment, string decay and domain wall decay thermalize as a result of their gravitational self-interactions when the photon temperature is approximately 500 eV. They then…
We show that cold dark matter axions thermalize and form a Bose-Einstein condensate. We obtain the axion state in a homogeneous and isotropic universe, and derive the equations governing small axion perturbations. Because they form a BEC,…
Cold dark matter axions form a Bose-Einstein condensate if the axions thermalize. Recently, it was found that they do thermalize when the photon temperature reaches T ~ 100 eV(f/10^12GeV)^1/2 and that they continue to do so thereafter. We…
Cold dark matter axions thermalize through gravitational self-interactions and form a Bose-Einstein condensate when the photon temperature reaches approximately 500 eV. Axion Bose-Einstein condensation provides an opportunity to distinguish…
Axions differ from the other cold dark matter candidates in that they form a degenerate Bose gas. It is shown that their huge quantum degeneracy and large correlation length cause cold dark matter axions to thermalize through gravitational…
Bose-Einstein Condensation (BEC) cosmology is analyzed in the framework of a string-inspired axion model. The dispersion relation of the axionic mode includes both gravitational and self-interaction terms, the latter being small in…
QCD axions are a well-motivated candidate for cold dark matter. Cold axions are produced in the early universe by vacuum realignment, axion string decay and axion domain wall decay. We show that cold axions thermalize via their…
An argument is presented that the dark matter is axions, at least in part. It has three steps. First, axions behave differently from the other forms of cold dark matter because they form a rethermalizing Bose-Einstein condensate (BEC).…
We present a comprehensive theoretical investigation of Bose-Einstein condensates (BECs) and their manifestations in astrophysical and cosmological contexts. Building upon the foundations of quantum statistics in curved spacetime, we derive…
One of the leading candidates for dark matter is axion or axion-like particle in a form of Bose-Einstein condensate (BEC). In this paper, we present an analysis of 17 high-resolution galactic rotation curves from "The H{\footnotesize I}…
The hypothesis of an `invisible' axion was made by Misha Shifman and others, approximately thirty years ago. It has turned out to be an unusually fruitful idea, crossing boundaries between particle physics, astrophysics and cosmology. An…
The EDGES collaboration's observation of an anomalously strong 21 cm absorption feature around the cosmic dawn era has energised the cosmological community by suggesting a novel signature of dark matter in the cooling of cosmic hydrogen. In…
In trapped Bose-Einstein condensates (BECs), \emph{condensate growth} refers to the process in which an increasing number of quasi-particles are immediately transferred from the non-condensate state (the thermal cloud) into the condensate…
We analyze the behavior of axion dark matter before it falls into a galactic gravitational potential well. The axions thermalize sufficiently fast by gravitational self-interactions that almost all go to their lowest energy state consistent…
The dynamical behavior of Bose-Einstein condensation (BEC) in a gas with attractive interactions is striking. Quantum theory predicts that BEC of a spatially homogeneous gas with attractive interactions is precluded by a conventional phase…
It was shown in ref. [1] that cold dark matter axions reach thermal contact with baryons, and therefore cool them, shortly after the axions thermalize among themselves and form a Bose-Einstein condensate. The recent observation by the EDGES…
The axion is a motivated cold dark matter candidate, which it would be interesting to distinguish from weakly interacting massive particles. Sikivie has suggested that axions could behave differently during non-linear galaxy evolution, if…
We study the Bose condensation of scalar dark matter in the presence of both gravitational and self-interactions. Axions and other scalar dark matter in gravitationally bound miniclusters or dark matter halos are expected to condense into…
Recently there has been significant interest in the claim that dark matter axions gravitationally thermalize and form a Bose-Einstein condensate with cosmologically long-range correlation. This has potential consequences for galactic scale…
Axions differ from ordinary cold dark matter, such as WIMPs or sterile neutrinos, because they form a Bose-Einstein condensate (BEC). As a result, axions accreting onto a galactic halo fall in with net overall rotation. In contrast,…