Related papers: Dimming Supernovae without Cosmic Acceleration
We present some bottom-up motivations of axions and other weakly interacting sub-eV particles (WISPs) coupling to photons. Typically, these light particles are strongly constrained by their production or interaction in astrophysical and…
We use a series of ray-tracing experiments to determine the magnification distribution of high-redshift sources by gravitational lensing. We determine empirically the relation between magnification and redshift, for various cosmological…
We consider the minimal coupling of two photons to neutral scalar and pseudoscalar fields, as for instance in the case of the Higgs boson and axion, respectively. In this framework, we analyze the photon dispersion relations in the presence…
We discuss axion dark matter detection via two mechanisms: spontaneous decays and resonant conversion in neutron star magnetospheres. For decays, we show that the brightness temperature signal, rather than flux, is a less ambiguous measure…
In supersymmetric theories, the presence of axions usually implies the existence of a non-compact, (pseudo)moduli space. In gauge mediated models, the axion would seem a particularly promising dark matter candidate. The cosmology of the…
Axion-like particles can be abundantly produced through scattering processes in the cores of neutron stars (NSs). If they are ultralight ($m_a \lesssim 10^{-4}$ eV), then they can efficiently convert to detectable photons in the external NS…
Axion--photon interactions can lead to an enhancement of the electromagnetic field by parametric resonance in the presence of a cold axion background, for modes with a frequency close to half the axion mass. In this paper, we study the role…
Magnetic fields between a supernova (SN) and Earth convert axions into gamma rays. The absence of such a signal in coincidence with SN 1987A neutrinos, using the coherent Milky Way field, provides well-studied constraints on $g_{ap}\times…
Supernovae provide fascinating opportunities to study various particles and their interactions. Among these there are neutrinos, axions, and other light weakly interacting particles, which play a significant role in our understanding of…
A cold relic axion condensate resulting from vacuum misalignment in the early universe oscillates with a frequency \sim m_a, where m_a is the axion mass. We summarize how the properties of photons propagating in such a medium are modified.…
Despite growing interest and extensive effort to search for ultralight dark matter in the form of a hypothetical dark photon, how it fits into a consistent cosmology is unclear. Several dark photon dark matter production mechanisms proposed…
Recently it has been suggested that dark radiation in the form of axions produced during the decay of string theory moduli fields could be responsible for the soft x-ray excess in galaxy clusters. These soft X-ray photons come about due to…
Axion as a coherently oscillating scalar field is known to behave as a cold dark matter in all cosmologically relevant scales. For conventional axion mass with 10^{-5} eV, the axion reveals a characteristic damping behavior in the evolution…
Axion couplings to photons could induce photon-axion conversion in the presence of magnetic fields in the Universe. This conversion could impact various cosmic distance measurements, such as luminosity distances to type Ia supernovae and…
Axion dark matter or any ultralight bosonic dark matter can go through Bose-Einstein condensation due to the large phase density, leading to the formation of axion stars or solitons in dark matter halo centers. The formation rate is…
A dark photon may kinetically mix with the ordinary photon, inducing oscillations with observable imprints on cosmology. Oscillations are resonantly enhanced if the dark photon mass equals the ordinary photon plasma mass, which tracks the…
We revisit the cosmological constraints on resonant and non-resonant conversion of photons to axions in the cosmological magnetic fields. We find that the constraints on photon-axion coupling and primordial magnetic fields are much weaker…
We derive new constraints on the coupling of heavy pseudoscalar (axion-like) particles to photons, based on the gamma ray flux expected from the decay of these particles into photons. After being produced in the supernova core, these heavy…
The axion photon system in an external magnetic field, when the direction of propagation of axions and photons is orthogonal to the direction of the external magnetic field, displays a continuous axion-photon duality symmetry in the limit…
Dark photons can be resonantly produced in the early universe via their coupling to an oscillating axion field. However, this mechanism typically requires large axion--dark photon couplings or some degree of fine-tuning. In this work, we…