Related papers: Axion Production in Pulsar Magnetosphere Gaps
Since pulsars were discovered as emitters of bright coherent radio emission more than half a century ago, the cause of the emission has remained a mystery. In this Letter we demonstrate that coherent radiation can be directly generated in…
Pulsars play a crucial astrophysical role as the highly energetic compact radio, X-ray, and gamma-ray sources. Our previous works show that the radio pulsars found as the pulsing gamma sources by the Large Area Telescope (LAT) on the board…
Gravitationally bound clumps of dark matter axions in the form of 'miniclusters' or even denser 'axion stars' can generate strong radio signals through axion-photon conversion when encountering highly magnetised neutron star magnetospheres.…
It is proposed that radiation belts similar to the ones in the planetary magnetosphere can exist for a pulsar with a relatively long period and a strong magnetic field. In the belts located in the closed field line region near the light…
In this article we treat the non-adiabatic photon-to-axion resonant conversion of curvature radiation, synchrotron emission and inverse Compton scattering dominating the spectral density function of pulsars. First, we introduce emission…
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…
Models that produce Axion-Like-Particles (ALP) after cosmological inflation due to spontaneous $U(1)$ symmetry breaking also produce cosmic string networks. Those axionic strings lose energy through gravitational wave emission during the…
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…
The axion is well motivated in physics. It solves the strong charge conjugation-parity reversal problem CP in fundamental physics and the dark matter problem in astronomy. Its interaction with the electromagnetic field has been expected but…
Axions are well-motivated candidates for dark matter. Recently, much interest has focused on the detection of photons produced by the resonant conversion of axion dark matter in neutron star magnetospheres. Various groups have begun to…
Following the basic principles of a charge separated pulsar magnetosphere \citep{goldreich1969}, we consider the magnetosphere be stationary in space, instead of corotating, and the electric field be uploaded from the potential distribution…
Non-thermal magnetospheric processes in the vicinity of supermassive black holes have attracted particular attention in recent times. Gap-type particle acceleration accompanied by curvature and Inverse Compton radiation could in principle…
Temporal offsets between Gamma-Ray Bursts (GRBs) and high-energy neutrinos provide a useful probe of propagation effects in extreme astrophysical environments. We investigate whether such offsets can be generated by photon propagation…
It is shown that pulsar radio emission can be generated effectively through a streaming motion in the polar-cap regions of a pulsar magnetosphere causing nonresonant growth of waves that can escape directly. As in other beam models, a…
Recently, two of the present authors showed that even when the axion momentum is much smaller than its mass, the axion can still behave like radiation if its energy density greatly exceeds the maximum potential energy set by the cosine-type…
It is known that a coherently oscillating axion field is a candidate of the dark matter. In the presence of the oscillating axion, the photon can be resonantly produced through the parametric amplification. In the universe, there also exist…
Black holes can launch powerful jets through the Blandford-Znajek process. This relies on enough plasma in the jet funnel to conduct the necessary current. However, in some low luminosity active galactic nuclei, the plasma supply near the…
Magnetars in quiescent states continue to emit hard X-rays with a power far exceeding the loss of rotational energy. It has recently been noted that this hard X-ray continuum may bear a direct signature of quantum electrodynamic (QED)…
By coupling to both the Higgs and electroweak gauge sectors, an axion can generate the matter-antimatter asymmetry in the universe via electroweak baryogenesis when the axion decay constant lies within the range of approximately $10^5$ and…
Relativistic axion-like particles (ALPs) originating from the stellar interiors, along with the ones coming from photon-ALP mixing in the galactic magnetic fields, contribute together to make an energetic component of the ALP content of the…