Related papers: Foamy Dark Matter from Monodromies
Light pseudo-Nambu-Goldstone bosons (pNGBs) such as, e.g.~axion-like particles, that are non-thermally produced via the misalignment mechanism are promising dark matter candidates. An important feature of pNGBs is their periodic potential,…
Axion-like particle (ALP) dark matter shows distinctive behavior on scales where wavelike effects dominate over self-gravity. Ultralight axions are candidates for fuzzy dark matter (FDM) whose de Broglie wavelength in virialized halos…
The misalignment mechanism for axion-like particles (ALPs) is a leading explanation for dark matter. In this work we investigate ALPs with non-periodic potentials, which allow for large misalignment of the field from the minimum and make it…
Axions and axion-like particles (ALPs) are among the most popular candidates that explain the origin of the mysterious dark matter. The most popular ALP production mechanism studied in the literature is the misalignment mechanism, where an…
Assuming that dark matter is an ultralight pseudoscalar particle which couples to electromagnetism like an axion (an ALP), we demonstrate that the coupling of the cosmological magnetic field produced by the ALP field oscillations to the…
Adding an axion-like particle (ALP) to the Standard Model, with a field velocity in the early universe, simultaneously explains the observed baryon and dark matter densities. This requires one or more couplings between the ALP and photons,…
Dark matter may be composed of ultra-light bosons whose de Broglie wavelength in galaxies is of order 1 kpc. The standard model for this fuzzy dark matter (FDM) is a complex scalar field that obeys the Schr\"odinger-Poisson equations. The…
A rotation in the field space of a complex scalar field corresponds to a Bose-Einstein condensation of $U(1)$ charges. We point out that fluctuations in this rotating condensate exhibit sound-wave modes, which can be excited by cosmic…
Fuzzy dark matter of ultra-light axions has gained attention, largely in light of the galactic scale problems associated with cold dark matter. But the large de Broglie wavelength, believed to possibly alleviate these problems, also leads…
Dark matter may be composed of light bosons, ${m_b \sim 10^{-22}\, \mathrm{eV}}$, with a de Broglie wavelength $\lambda \sim 1 \,\mathrm{kpc}$ in typical galactic potentials. Such `fuzzy' dark matter (FDM) behaves like cold dark matter…
Scale-invariant fluctuations and cold dark matter could originate from two different modes of a single scalar field, fluctuations from massless Goldstone oscillations and matter from massive Higgs modes. Matching the fluctuations and dark…
Large-amplitude isothermal fluctuations in the dark matter energy density, parameterized by $\Phi\equiv\delta\rhodm/\rhodm$, are studied within the framework of a spherical collapse model. For $\Phi \ga 1$, a fluctuation collapses in the…
The axion-like particles (ALPs) are very good candidates of the cosmological dark matter, which can exist in many extensions of the standard model (SM). The mass range of the ALPs as the dark matter can extend from a sub-eV scale to almost…
Axion-like dark matter whose symmetry breaking occurs after the end of inflation predicts enhanced primordial density fluctuations at small scales. This leads to dense axion minihalos (or miniclusters) forming early in the history of the…
Axion-like particles (ALPs) are leading candidates to explain the dark matter in the universe. Their production via the misalignment mechanism has been extensively studied for cosine potentials characteristic of pseudo-Nambu-Goldstone…
Motivated by their potential role as dark matter, we study the cosmological evolution of light scalar and vector fields non-minimally coupled to gravity. Our focus is on a situation where the dominant contribution to the energy density…
Theories with several hundred axion fields have enormous numbers of distinct meta-stable minima. A small fraction of these local minima have vacuum energy compatible with current measurements of dark energy. The potential also contains…
We discuss how to formulate a quantum field theory of dark energy interacting with dark matter. We show that the proposals based on the assumption that dark matter is made up of heavy particles with masses which are very sensitive to the…
It has recently been shown [1] that light vector particles produced from inflationary fluctuations can give rise to the dark matter in the Universe. A similar mechanism has been discussed in [2] for a non-minimally coupled scalar enjoying a…
Cosmic birefringence is predicted if an axion-like particle (ALP) moves after the recombination. We show that this naturally happens if the ALP is coupled to the dark matter density because it then acquires a large effective mass after the…