Related papers: Extensive air showers with TeV-scale quantum gravi…
The hybrid design of the Pierre Auger Observatory allows for the measurement of a number of properties of extensive air showers initiated by ultra-high energy cosmic rays. By comparing these measurements to predictions from air shower…
In order to get the primary energy of cosmic rays from their extensive air showers using the fluorescence detection technique, the invisible energy should be added to the measured calorimetric energy. The invisible energy is the energy…
The detection of gravitational waves and neutrinos from astrophysical sources with gamma-ray counterparts officially started the era of Multi-Messenger Astronomy. Their transient and extreme nature implies that monitoring the VHE sky is…
The particle density in extensive air showers fluctuates at the ground level. These fluctuations, at the scale of the scintillator detector size (several meters), lead to the diversity of the individual detector responses. Therefore, small…
We consider a theory with isotropic nonbirefringent Lorentz violation in the photon sector and explore the effects on the development of the electromagnetic component of extensive air showers in the Earth atmosphere. Specifically, we…
The two most powerful extensive air showers (EAS) with energies of about $10^{20}$ eV, registered at the Yakutsk EAS array during the entire observation period of 1974-2024, are considered. Both showers hit the array near the center and…
The origin of the ultra high energy cosmic ray (UHECR) showers has remained as a mystery among particle physicists and astrophysicists. In low scale gravity models, where the neutrino-nucleon cross section rises to typical hadronic values…
In this article I review the main theoretical problems that are posed by the highest energy end of the observed cosmic ray spectrum, stressing the importance of establishing their composition in order to decide between proposed scenarios. I…
The Pierre Auger Observatory aims to determine the nature and origin of the ultra-high energy cosmic rays (UHECR). The Auger hybrid detector combines fluorescence observations of extended air showers, initiated in the atmosphere by these…
We study prospects for the observations of high-energy cosmic tau neutrinos (E \geq 10^6 GeV) originating from proton acceleration in the cores of active galactic nuclei. We consider the possibility that vacuum flavor neutrino oscillations…
High-energy neutrino astronomy represents an open window both on astrophysical mechanisms of particle acceleration and on fundamental interactions. The possibility of detecting them in large earth-based apparatus, like AUGER, AMANDA,…
High energy neutrinos play a very important role for the understanding of the origin and propagation of ultra high energy cosmic rays (UHECR). They can be produced as a consequence of the hadronic interactions suffered by the cosmic rays in…
The Pierre Auger Observatory has already collected more ultra high energy cosmic ray data than all the previous experiments. With an hybrid detection technique, it can provide coherent results on the flux, energy spectrum and arrival…
Extensive air showers of cosmic rays with energies above 5.10**18 eV registered by the Yakutsk array have been analyzed. The existence of showers without muon component is found. Among them we found 5 clusters and these clusters correlate…
The Surface Detector of the Pierre Auger Observatory is sensitive to neutrinos of all flavours above 0.1 EeV. These interact through charged and neutral currents in the atmosphere giving rise to extensive air showers. When interacting…
We present the design and science case for a new array of radio antennas to be located at the Pierre Auger Observatory. Six stations of three SKALA antennas each will be deployed around a single water-Cherenkov surface detector triggering…
The longitudinal profile of extensive air showers is sensitive to the energy and type/mass of the primary particle. One of its characteristics, the atmospheric depth of shower maximum, is often used to reconstruct the elemental composition…
The development of cosmic ray air showers can be influenced by atmospheric electric fields. Under fair weather conditions these fields are small, but the strong fields inside thunderstorms can have a significant effect on the…
This paper summarizes the status and the recent measurements from the Pierre Auger Observatory. The energy spectrum is described and its features discussed. We report searches for anisotropy of cosmic ray arrival directions on large scales…
The primary cosmic rays particles with energies above 10**20 eV have been observed at many extensive air shower arrays since the beginning of observations over 40 years ago. The validity of measurements of signal s(600) used as energy…