In this work we present the interpretation of the energy spectrum and mass composition data
as measured by the Pierre Auger Collaboration above 6× 1017 eV. We use an astrophysical …

Cosmic rays are energetic charged particles from extraterrestrial sources, with the highest-
energy events thought to come from extragalactic sources. Their arrival is infrequent, so …

In this paper, I present a qualitative discussion on the prospect of production of ultra-high
photons in blazars. The sources are a subclass of active galactic nuclei which host …

We revisit constraints on decaying very heavy dark matter (VHDM) using the latest ultrahigh-
energy cosmic-ray (UHECR; E≳ 10 18 eV) data and ultrahigh-energy (UHE) γ-ray flux upper …

Using the data of the Pierre Auger Observatory, we report on a search for signatures that
would be suggestive of super-heavy particles decaying in the Galactic halo. From the lack of …

Galaxy clusters are the largest objects in the Universe kept together by gravity. Most of their
baryonic content is made of a magnetized diffuse plasma. We investigate the impact of such …

We consider the prospects for future ultrahigh energy cosmic ray and neutrino observations
to constrain the evolution of sources producing a proton flux above 10 EeV (1 EeV= 10 18 …

We use the surface detector of the Pierre Auger Observatory to search for air showers
initiated by photons with an energy above 1019 eV. Photons in the zenith angle range from …

We study the general properties of the freeze-out of a thermal relic. We give analytic
estimates of the relic abundance for an arbitrary freeze-out process, showing when …

With the first gravitational waves (GWs) measured by the Advanced LIGO and Virgo
detectors in 2015 (Abbott et al. 2016), a new window to the universe has been opened. In …