Title:
"Recent results from the Pierre Auger Observatory"
Abstract:
The Pierre Auger Observatory is designed to measure the flux
of cosmic rays at the highest energies ($\gtrsim 10^{18}$~eV),
by employing a unique hybrid technique using water Cherenkov
tanks on ground and fluorescence telescopes. The Southern part
of the Pierre Auger Observatory, nearing completion, has now
collected a large sample of data which has brought a
significant improvement over cosmic ray measurements
previously reported by the Pierre Auger Observatory. We
present a summary of the recent results: the energy spectrum,
energy-dependence of the depth of shower maximum, and number
of muons measured in the ground detectors. The latter two
measurements place constraints on hadronic interaction models
at center-of-mass energies above 100~TeV, while providing
clues on the composition of the cosmic ray flux at the highest
energies.