The origin of high-energy cosmic rays, and their behavior in astrophysical sources, remains
an open question. Recently, new ways to address this question have been made possible …

Understanding the anisotropy of ultra high-energy cosmic rays (UHECRs) is crucial for
unraveling the origins and propagation mechanisms of these enigmatic particles. In this …

Radio-based detection of high-energy particles is growing in maturity. In this chapter, we
focus on the detection of neutrinos with energies in excess of 10 PeV that interact in the …

Ultra-high energy cosmic rays (UHECRs) beyond the Greisen-Zatsepin-Kuzmin (GZK) cut-off
provide us with a unique opportunity to understand the universe at extreme energies …

Over the last decade, observations have shown that the mean mass of ultra-high-energy
cosmic rays (UHECRs) increases progressively toward the highest energies. However, the …

We present a full model of surface-detector responses to extensive air showers. The model
is motivated by the principles of air-shower universality and can be applied to different types …

These notes summarize the lectures about “Cosmic-ray propagation in extragalactic space
and secondary messengers”, focusing in particular on the interactions of cosmic-ray …

The unified models of astrophysical sources to account for ultrahigh-energy cosmic rays
(UHECRs) and high-energy cosmic neutrinos with energies greater than 100 TeV have …

We reexamine the interactions of ultra-high-energy cosmic rays (UHECRs) with photons
from the cosmic microwave background (CMB) under a changed, locally nonlinear …

Ultrahigh-energy neutrinos (UHE $\nu $ s) can be used as a valuable probe of superheavy
dark matter above $\sim 10^ 9$ GeV, the latter being difficult to probe with collider and direct …