Analyzing ultra-high-energy cosmic rays’ anisotropy in f(R,T) gravity theory

In this study, we investigated the anisotropy of diffusive Ultra-High-Energy Cosmic Rays (UHECRs) by employing three cosmological models: two models from the [Formula: see text] gravity theory and the other is the standard [Formula: see text]CDM model. The primary objective of this work was to ascertain the role of the [Formula: see text] gravity theory in comprehending the anisotropy of UHECRs without implicitly endorsing the conventional cosmology. We parameterized the magnetic field and the source distance in anisotropy calculations to align well with the observational data from the Pierre Auger Observatory for all the cosmological models. An uncertainty band is presented along with the [Formula: see text] test for all cosmological models to demonstrate the goodness of fitting. Our findings revealed that the amplitude of the anisotropy is highly sensitive to these cosmological models. Notably, the [Formula: see text] models exhibited a lower amplitude of anisotropy (i.e. more isotropy), while the [Formula: see text]CDM model predicted a comparatively higher amplitude at most of the energies considered.