相关论文: Axion-Photon Conversion In Magnetized Universe: Im…
We examine the resonant conversion of axion-like particle (ALP) or dark photon to the electromagnetic photon in the early Universe, which takes place due to the ALP-photon-dark photon oscillations in background dark photon gauge fields. It…
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…
Recently the EDGES experiment reported an enhanced 21cm absorption signal in the radio wave observation, which may be interpreted as either anomalous cooling of baryons or heating of cosmic microwave background photons. In this paper, we…
Two notable anomalies in radio observations -- the excess radiation in the Rayleigh-Jeans tail of the cosmic microwave background, revealed by ARCADE2, and the twice-deeper absorption trough of the global 21cm line, identified by EDGES --…
Ultra-light hidden-photon dark matter produces an oscillating electric field in the early Universe plasma, which in turn induces an electric current in its ionized component whose dissipation results in heat transfer from the dark matter to…
Recently it has been pointed out that a cosmic background of relativistic axion-like particles (ALPs) would be produced by the primordial decays of heavy fields in the post-inflation epoch, contributing to the extra-radiation content in the…
Primordial magnetic fields (PMFs) may significantly influence 21-cm physics via two mechanisms: (i) magnetic heating of the intergalactic medium (IGM) through ambipolar diffusion (AD) and decaying magnetohydrodynamic turbulence (DT), (ii)…
The presence of a primordial magnetic field would have induced resonant conversions between photons and axion-like particles (ALPs) during the thermal history of the Universe. These conversions would have distorted the blackbody spectrum of…
We study prospects of constraining the primordial magnetic field (PMF) and its evolution during the dark ages and cosmic dawn in light of EDGES 21-cm signal. Our analysis has been carried out on a `colder IGM' background which is one of the…
In the presence of a background magnetic field, axions or axion-like particles (ALPs) can be resonantly converted to photons when their mass is nearly equal to the effective photon mass. In this paper, we propose a novel method to constrain…
Axion-like particles (ALPs) and photons can quantum mechanically interconvert when propagating through magnetic fields, and ALP-photon conversion may induce oscillatory features in the spectra of astrophysical sources. We use deep (370 ks),…
Axion-like particles (ALPs), predicted in theories beyond the Standard Model, can have observational effects on the transparency of the Universe to $\gamma$ rays in the presence of magnetic fields. In this work, we search for effects…
We study the constraints on primordial magnetic fields (PMFs) in the light of the Experiment to Detect the Global Epoch of Reionization Signature (EDGES) low-band observation and Absolute Radiometer for Cosmology, Astrophysics and Diffuse…
We study the constraints on primordial magnetic fields (PMFs) in light of the global 21-cm signal observed during the dark ages. Primordial magnetic fields can heat the intergalactic medium (IGM) via magnetohydrodynamic effects. We…
The cosmological 21-cm signal from neutral hydrogen, which is considered as a promising tool, is being used to observe and study the cosmic dawn (CD) and epoch of reionization (EoR). A significant part of this thesis focuses on the…
We identify a new resonance, axion magnetic resonance (AMR), that can greatly enhance the conversion rate between axions and photons. A series of axion search experiments rely on converting them into photons inside a constant magnetic field…
The intrinsic flux of very high energy (VHE, Energy > 100 GeV) gamma-rays from extragalactic sources is attenuated due to pair production in the interaction with photons of the extragalactic background light (EBL). Depending on the distance…
Axion Like Particles (ALPs) are predicted to couple with photons in the presence of magnetic fields. This effect may lead to a significant change in the observed spectra of gamma-ray sources such as AGNs. Here we carry out a detailed study…
Axion-Like Particles (ALPs) are predicted by many extensions of the Standard Model and give rise to characteristic dimming and polarization effects in a light beam travelling in a magnetic field. In this Letter, we demonstrate that…
Axionlike particles (ALPs) are hypothetical light (sub-eV) bosons predicted in some extensions of the Standard Model of particle physics. In astrophysical environments comprising high-energy gamma rays and turbulent magnetic fields, the…