Related papers: The Pierre Auger Observatory and Physics Beyond th…
We use more than two years of data from the Pierre Auger Observatory to search for anisotropies on large scales in different energy windows. We account for various systematics in the acceptance, in particular due to the array growth and…
Astroparticle physics has recently reached a new status of precision due to the construction of new observatories, operating innovative technologies and the detection of large numbers of events and sources. The precise measurements of…
The status of solutions to the ultra-high energy cosmic ray puzzle that involve particle physics beyond the standard model is reviewed. Signatures and experimental constraints are discussed for most proposals like the Z burst model and…
Studies of the composition of the highest energy cosmic rays with the Pierre Auger Observatory, including examination of hadronic physics effects on the structure of extensive air showers.
The world's largest cosmic-ray detector is nearing completion in the remote Pampas of Argentina. This instrument measures extensive air-showers with energies from ${10^{18}-10^{20}}$ eV and beyond. A surface detector array of area 3000…
Recent results obtained with the Pierre Auger Observatory are described. These include measurements of the spectrum, anisotropies and composition of ultra-high energy cosmic rays. The ankle of the spectrum is measured at $4\times…
The mass composition of ultra-high-energy cosmic rays is an open problem in astroparticle physics. It is usually inferred from the depth of the shower maximum (Xmax) of cosmic-ray showers, which is only ambiguously determined by modern…
Determining anisotropies in the arrival directions of cosmic rays at the highest energy is an important task in astrophysics. It is common and useful to partition the sky into spherical harmonics as a measure of anisotropy. The two lowest…
The Pierre Auger Observatory (PAO) has measured the spectrum and composition of the ultrahigh energy cosmic rays with unprecedented precision. We use these measurements to constrain their spectrum and composition as injected from their…
The questions about the origin and type of cosmic particles are not only fascinating for scientists in astrophysics, but also for young enthusiastic high school students. To familiarize them with research in astroparticle physics, the…
The impact of the solar activity on the heliosphere has a strong influence on the modulation of the flux of low energy galactic cosmic rays arriving at Earth. Different instruments, such as neutron monitors or muon detectors, have been…
We consider the ultra-high energy cosmic ray (UHECR) spectrum as measured by the Pierre Auger Observatory. Top-down models for the origin of UHECRs predict an increasing photon component at energies above about $10^{19.7}$eV. Here we…
The assumption of Lorentz invariance is one of the founding principles of Modern Physics and violation of it would have profound implications to our understanding of the universe. For instance, certain theories attempting a unified theory…
The origins of ultra-high energy cosmic rays (UHECRs) remain an open question. Several attempts have been made to cross-correlate the arrival directions of the UHECRs with catalogs of potential sources, but no definite conclusion has been…
It is assumed that superheavy dark matter particles with O(EeV) mass may decay to relativistic milli-charged particles (MCPs). The upward-going MCPs passing through the Earth could be measured by the fluorescence detectors (FD) of the…
As a basic symmetry of Einstein's theory of special relativity, Lorentz invariance has withstood very strict tests. But there are still motivations for such tests. Firstly, many theories of quantum gravity suggest violations of Lorentz…
A thorough search for large scale anisotropies in the distribution of arrival directions of cosmic rays detected above $10^{18}$ eV at the Pierre Auger Observatory is presented. This search is performed as a function of both declination and…
In this paper some recent results from the Pierre Auger Collaboration are presented. These are the measurement of the energy spectrum of cosmic rays over a wide range of energies ($10^{17.5}$ to above $10^{20}$ eV), studies of the…
In this proceeding we present the construction status and the performances of the Pierre Auger Observatory together with the first results obtained with our initial 18 month of data. In particular, we discuss our search for anisotropy near…
If clustering of the arrival directions of ultra high energy cosmic rays is discovered, this would provide important information about their origin, composition, and the galactic and extragalactic magnetic fields. We present here the…