Related papers: First constraints on axion-like particles from Gal…
GeV-TeV gamma-ray and PeV-EeV neutrino backgrounds provide a unique window on the nature of the ultra-high-energy cosmic-rays (UHECRs). We discuss the implications of the recent Fermi-LAT data regarding the extragalactic gamma-ray…
Active galactic nuclei (AGN) can produce both gamma rays and cosmic rays. The observed high-energy gamma-ray signals from distant blazars may be dominated by secondary gamma rays produced along the line of sight by the interactions of…
Blazars are potential candidates of cosmic-ray acceleration up to ultrahigh energies ($E\gtrsim10^{18}$ eV). For an efficient cosmic-ray injection from blazars, $p\gamma$ collisions with the extragalactic background light (EBL) and cosmic…
We provide our estimates of the intensity of the gamma-ray emission with an energy near 0.1 TeV generated in inrergalactic space in the interactions of cosmic rays with background emissions. We assume that the cosmic ray sources are…
Axion-Like-Particles (ALPs) are hypothetical pseudo-scalar particles actively searched as light dark matter candidates. The coupling of ALPs to photons can give rise to distinctive spectral features in the observed gamma-ray spectrum of…
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…
Axion-like particles (ALPs) appear in various new physics models with spontaneous global symmetry breaking. When the ALP mass is in the range of MeV to GeV, the cosmology and astrophysics bounds are so far quite weak. In this work, we…
The diffuse Galactic $\gamma$-ray emission originates from the interactions between cosmic rays and the interstellar medium or radiation fields within our Galaxy, where the production of neutrinos is also anticipated. Recently, the Large…
The axion-like particles (ALPs) are very good candidates of the cosmological dark matter, which can exist in many extensions of the standard model (SM). The mass range of the ALPs as the dark matter can extend from a sub-eV scale to almost…
The diffuse gamma-ray emission between 10 and 1000 TeV from the Galactic plane was recently measured by the Large High Altitude Air Shower Observatory (LHAASO). These observations will help tremendously in constraining the propagation and…
Hypothetical axion-like particles (ALPs) are of interest because of their potential to act as dark matter or to reveal information about yet undiscovered fundamental constituents of matter. Such particles can be created when photons…
The IceCube Neutrino Observatory at the South Pole has measured astrophysical neutrinos using through-going and starting events in the TeV to PeV energy range. The origin of these astrophysical neutrinos is still largely unresolved, and…
One attractive scenario for the excess of sub-PeV/PeV neutrinos recently reported by IceCube is that they are produced by cosmic rays in starburst galaxies colliding with the dense interstellar medium. These proton-proton ($pp$) collisions…
We investigate the characteristics of the gamma-ray signal following the decay of MeV-scale Axion-Like Particles (ALPs) coupled to photons which are produced in a Supernova (SN) explosion. This analysis is the first to include the…
The flux of very high-energy neutrinos produced in our Galaxy by the interaction of accelerated cosmic rays with the interstellar medium is not yet determined. The characterization of this flux will shed light on Galactic accelerator…
Protoneutron stars, highly compact objects formed in the core of exploding supernovae (SNe), are powerful sources of axion-like particles (ALPs). In the SN core, ALPs are dominantly produced via nucleon-nucleon bremsstrahlung and pion…
Very high energy (VHE) gamma-rays undergo pair production with low energy photons of background radiation fields. This leads to an attenuation of the primary gamma-ray flux of extragalactic sources in the interaction with the extragalactic…
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),…
The hot interiors of massive stars in the later stages of their evolution provide an ideal place for the production of heavy axion-like particles (ALPs) with mass up to O(100 keV) range. We show that a fraction of these ALPs could stream…
Axion-like particles (ALPs) can be copiously produced in binary neutron star (BNS) mergers through nucleon-nucleon bremsstrahlung if the ALP-nucleon couplings $g_{a N}$ are sizable. The ALP-photon coupling $g_{a\gamma}$ may trigger…