Related papers: Photon Production of Axionic Cold Dark Matter
We propose to search for axion dark matter via the oscillating electric dipole moments that axions induce in atoms and molecules. These moments are produced through the intrinsic oscillating electric dipole moments of nucleons and through…
Dark matter may be coupled to dark radiation: light degrees of freedom that mediate forces between dark sector particles. Cosmological constraints favor dark radiation that is colder than Standard Model radiation. In models with fixed…
Recent experiments suggest that polarized photons may couple significantly to pseudoscalar particles such as axions. We study the possible observational signatures of axion-photon coupling for radiation from magnetic stars, with particular…
We present a brief overview of the ongoing searches for the axion particle via its coupling to photons. Both the classical QCD axions and more recently proposed Axion-Like-Particles are considered. Astrophysical bounds on the axion-photon…
We investigate the production of dark radiation (DR) from axions and axion-like particles (ALPs) as potential origins of dark matter. Focusing on the dark matter misalignment mechanism, we examine non-thermal, pre-inflationary scenarios…
Contemporary attempts to explain the existence of ultra-high energy cosmic rays using plasma-based wakefield acceleration deliberately avoid non-Standard Model particle physics. However, such proposals exploit some of the most extreme…
Cosmological axions, an important dark matter candidate, are generated when a scalar field with a spontaneously broken O(2) invariance develops an explicitly O(2)-breaking tilt cosmologically, leading to coherent production of…
We revisit the production of axion-like particles (ALPs) coupled to electrons at tree-level in a relativistic plasma. We explicitly demonstrate the equivalence between pseudoscalar and derivative couplings, incorporate previously neglected…
In the hot environments of the anomalous X-ray pulsars and the soft gamma-ray repeaters, as indicated by their luminous, pulsed, quiescent X-ray emission, $\gamma$-rays generated from the inner gaps may have shorter attenuation lengths via…
We study the cosmological evolution of the QCD axion coupled to hidden photons. For a moderately strong coupling, the motion of the axion field leads to an explosive production of hidden photons by tachyonic instability. We use lattice…
Some of the most stringent constraints on physics beyond the Standard Model (BSM) arise from considerations of particle emission from astrophysical plasmas. However, many studies assume that particle production occurs in an isotropic plasma…
A light hidden photon or axion-like particle is a good dark matter candidate and they are often associated with the spontaneous breaking of dark global or gauged U(1) symmetry. We consider the dark Higgs dynamics around the phase transition…
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…
A dark photon may kinetically mix with the Standard Model photon, leading to observable cosmological signatures. The mixing is resonantly enhanced when the dark photon mass matches the primordial plasma frequency, which depends sensitively…
A system of light axions comprising a classical axion field, one candidate for dark matter, has an instability that can rapidly mix in photon pairs in a coherent fashion if initiated by a quantum break (which eliminates the need for seeds.)…
Axion-like particles (ALPs) are light, neutral, pseudo-scalar bosons predicted by several extensions of the Standard Model of particle physics -- such as the String Theory -- and are supposed to interact primarily only with two photons. In…
We consider the distribution of the axionic dark matter and the profiles of the axionically induced electric field on the background of a regular magnetic monopole. The background static spherically symmetric spacetime is considered to be…
Ultralight axions which couple sufficiently strongly to photons can leave imprints on the sky at diverse frequencies by mixing with cosmic light in the presence of background magnetic fields. We explore such direction dependent grey-body…
We calculate the amplitudes of the axion photoproduction off the nucleon, i.e., $\gamma N \to a N$, within the framework of chiral effective field theory. Several different types of contributions are simultaneously included in our…
Axions are pseudo-scalar particles, those arise because of breaking of Peccei Queen (PQ) symmetry. Axions have a tree level coupling to two photons. As a consequence there exists a tree level coupling of axion to photon in a magnetic field.…