Speaker
Description
While the origins of ultra-high energy (UHE) cosmic rays remain shrouded in uncertainty, several important milestones have been reached in recent years in the experimental study of cosmic rays with energy above $10^{18}$ eV. Within the vast expanse of intergalactic space, turbulent magnetic fields (TMFs) are believed to pervade, and these fields could exert a significant influence on the journey of UHECRs across the expanding Universe, which is currently undergoing acceleration. Thus, it is imperative to incorporate these considerations into our theoretical framework to gain a deeper understanding of the empirical observations related to UHECRs. In light of this, our research delves into the impact of UHE particle diffusion in the presence of TMFs, all within the context of the f(R) gravity power-law model. f(R) gravity is a type of modified gravity theory that generalizes Einstein's general relativity by replacing the Ricci scalar R with an arbitrary function f(R) in the geometric part of the action. Based on the f(R) gravity power-law model, we explore the diffusive behavior of UHECR protons, particularly focusing on their density enhancement throughout their propagation. We found that the f(R) gravity model considered here plays an effective role in the propagation of CRs and the results have lain within the required range. This research endeavor seeks to shed light on the intricate interplay between cosmic rays, magnetic fields, and gravity theories, contributing to a more comprehensive understanding of the fascinating realm of UHECRs.
