A dipole anisotropy in ultra–high-energy cosmic ray (UHECR) arrival directions, of
extragalactic origin, is now firmly established at energies E> 8 EeV. Furthermore, the …

A bstract The Standard Model Higgs potential seems unstable at field values h> h top~ 10
10 GeV. Vacuum decay can be triggered by N~ 4π/λ~ 1000 overlapped Higgs bosons with …

In the last decade, a wealth of observations of energetic astrophysical phenomena were
delivered with unprecedented precision. At ultra-high energies, the Pierre Auger and the …

Ultra-high-energy (E> 1018 electron volts) cosmic rays (UHECRs) are the highest energy
particles ever detected by human beings. Decades of measurements have revealed that …

The landscape of high-and ultra-high-energy astrophysics has changed in the last decade,
in large part owing to the inflow of high-quality data collected by present cosmic-ray, gamma …

This thesis focuses on ultra-high energy cosmic rays (UHECRs). The origin of these atomic
nuclei, discovered over a century ago and accelerated to hundreds of EeV, remains a …