Related papers: Axion Cloud Decay due to the Axion-photon Conversi…
We study interacting classical magnetic and pseudoscalar fields in frames of the axion electrodynamics. A large scale pseudoscalar field can be the coherent superposition of axions or axion like particles. We consider the evolution of these…
Cosmological moduli generically come to dominate the energy density of the early universe, and thereby trigger an early matter dominated era. Such non-standard cosmological histories are expected to have profound effects on the evolution…
Ultra light axion fields, motivated by the string theory, form a large condensate (axion cloud) around rotating black holes through superradiant instability. Several effects due to the axion cloud, such as the spin-down of black holes and…
It has been pointed out in the literature that in the presence of an external magnetic field the axion mass receives an electromagnetic contribution. We show that if a magnetic field with energy density larger than ~10^{-8} times the energy…
In this work we analyze the propagation of photons in an environment where a strong magnetic field (perpendicular to the photon momenta) coexists with an oscillating cold axion background with the characteristics expected from dark matter…
The radiative decay of the axion $a \to \gamma \gamma$ is investigated in an external electromagnetic field in DFSZ model in which axion couples to both quarks and leptons at tree level. The decay probability is strongly catalyzed by the…
Astrophysical gamma-ray sources come in a variety of sizes and magnetizations. We deduce general conditions under which gamma-ray spectra from such sources would be significantly affected by axion-photon mixing. We show that, depending on…
Axion dark matter can resonantly convert to photons in the magnetosphere of neutron stars, possibly giving rise to radio signals observable on Earth. This method for the indirect detection of axion dark matter has recently received…
We study the weak mixing of photons and relativistic axion-like particles (axions) in plasmas with background magnetic fields, ${\bf B}$. We show that, to leading order in the axion-photon coupling, the conversion probability, $P_{\gamma…
In certain laboratory experiments the production and/or detection of axions is due to the photon-axion transformations in a strong magnetic field. This process is coherent, and the rate of the transformation is proportional to the length…
The presence of axions introduces new diagrams at one-loop order to the two-photon decays of the neutral pion through axion-pion mixing. In this work, we calculate this correction, missing in all current calculations, in the framework of…
Very-high energy photons emitted by distant cosmic sources are absorbed on the extragalactic background light (EBL) during their propagation. This effect can be characterized in terms of a photon transfer function at Earth. The presence of…
It is shown that the electric current of massive fermions along the external magnetic field can be excited in the case when particles possess anomalous magnetic moments and electroweakly interact with background matter. This current is…
Magnetic field dependent transient solar observations are suggestive for axion-photon oscillations with light axion(-like) particle involvement. Novel dark-moon measurements with the SMART X-ray detectors can be conclusive for radiatively…
Superradiance can cause the axion cloud around a rotating black hole to reach extremely high densities, and the decay of these axions can produce a powerful laser. The electric field of these lasers is strong enough that the Schwinger…
It has been pointed out that the axion electrodynamics exhibits instability in the presence of a background electric field. We show that the instability leads to a complete screening of an applied electric field above a certain critical…
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…
We show how the properties of the QCD axion change in systems at finite baryonic density, such as neutron stars. At nuclear saturation densities, where corrections can be reliably computed, we find a mild reduction of the axion mass and up…
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…
We explore the possibility of axion-photon conversion as a common origin of two low-frequency anomalies: the isotropic radio excess (ARCADE2) and the deep global 21-cm absorption trough (EDGES). From the axion-photon action in an FLRW…