Related papers: Cosmic Axion Bose-Einstein Condensation
Axions are produced during a period of dilaton-driven inflation by amplification of quantum fluctuations. We show that for some range of string cosmology parameters and some range of axion masses, primordial axions may constitute a large…
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…
We propose experimental schemes for detection an axionic condensate supposed to be cosmic dark matter. Various procedures are considered in dependence on the value of the axion mass. There are well known indications that a large part of the…
We observe that photon cooling after big bang nucleosynthesis (BBN) but before recombination can remove the conflict between the observed and theoretically predicted value of the primordial abundance of $^7$Li. Such cooling is ordinarily…
Using recently developed nonrelativistic numerical simulation code, we investigate the stability properties of compact astrophysical objects that may be formed due to the Bose-Einstein condensation of dark matter. Once the temperature of a…
We study Bose-Einstein condensation and formation of Bose stars in the virialized dark matter halos/miniclusters by universal gravitational interactions. We prove that this phenomenon does occur and it is described by kinetic equation. We…
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 QCD axion or axion-like particles are candidates of dark matter of the universe. On the other hand, axion-like excitations exist in certain condensed matter systems, which implies that there can be interactions of dark matter particles…
Dark matter consisting of ultralight bosons can form a macroscopic Bose-Einstein condensate with distinctive observational signatures. While this possibility has been extensively studied for axions and axion-like particles $-$ pseudoscalars…
We study a cosmological model in which the boson dark matter gradually condensates into dark energy. Negative pressure associated with the condensate yields the accelerated expansion of the Universe and the rapid collapse of the smallest…
Despite many decades of study the physical origin of "dark matter" in the Universe remains elusive. In this letter we calculate the properties of a completely new dark matter candidate - Bose-Einstein condensates formed from a recently…
Axion-like particles are a well-motivated dark matter candidate that can form a condensate with low momentum and high occupation number. In the presence of dark radiation, this condensate loses energy, naturally increasing the energy…
The cosmological scenario where the Peccei-Quinn symmetry is broken after inflation is investigated. In this scenario, topological defects such as strings and domain walls produce a large number of axions, which contribute to the cold dark…
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…
Cold and hot dark matter (CDM, HDM) imprint distinctive effects on the cosmological observables, naturally, they are often thought to be made of different kinds of particles. However, we point out that CDM and HDM could share a common…
We review current cosmological constraints on the axion. We describe the basic mechanisms by which axions are created in the early universe, focussing on the standard thermal scenario where the dominant process is through axion radiation by…
A kinetic mixing between the axion and the inflaton allows for a production of axion dark matter even if the inflationary Hubble scale is smaller than the zero-temperature axion mass. We analyze the axion dynamics in this recently…
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…
Relativistic axions are good candidates for the dark radiation for which there are mounting observational hints. The primordial decays of heavy fields produce axions which are ultra-energetic compared to thermalised matter and inelastic…
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…