We review open questions and prospects for progress in ultrahigh-energy cosmic ray
(UHECR) research, based on a series of discussions that took place during the “The High …

In the last fifteen years radio detection made it back to the list of promising techniques for
extensive air showers, firstly, due to the installation and successful operation of digital radio …

We report a measurement of the energy spectrum of cosmic rays for energies above 2.5× 10
18 eV based on 215,030 events recorded with zenith angles below 60°. A key feature of the …

Abstract The Probe Of Extreme Multi-Messenger Astrophysics (POEMMA) is designed to
accurately observe ultra-high-energy cosmic rays (UHECRs) and cosmic neutrinos from …

We report a study of the distributions of the depth of maximum, X max, of extensive air-
shower profiles with energies above 1 0 17.8 eV as observed with the fluorescence …

We present the first hybrid measurement of the average muon number in air showers at
ultrahigh energies, initiated by cosmic rays with zenith angles between 62° and 80°. The …

Abstract The Pierre Auger Observatory, located on a vast, high plain in western Argentina, is
the world׳ s largest cosmic ray observatory. The objectives of the Observatory are to probe …

In this paper we review air shower data related to the mass composition of cosmic rays
above 1015eV. After explaining the basic relations between air shower observables and the …

In this contribution, we review the status and perspectives of direct neutrino mass
experiments, which investigate the kinematics of β‐decays of specific isotopes (3H, 187Re …

The Pierre Auger Observatory has begun a major Upgrade of its already impressive
capabilities, with an emphasis on improved mass composition determination using the …