Effects of cosmological constant on motion of UHECR particles  

作　　者：CHEN Shaoxia & CHANG Zhe Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100039, China Graduate School of Chinese Academy of Sciences, Beijing 100039, China 

出　　处：《Science China(Physics,Mechanics & Astronomy)》2005年第1期44-56,共13页中国科学：物理学、力学、天文学（英文版）

基　　金：The work was supported partly by the National Natural Science Foundation of China(Grant No.10375072).

摘　　要：Recent astronomical observations manifest that about two-thirds of the whole energy in the Universe is contributed by a small positive cosmological constant A (> 0). Then, an asymptotically de Sitter spacetime is premised naturally. However, physics in the de Sitter spacetime is very different from that in the Minkowski spacetime. As the first step, a covariant formalism of the kinematics in the de Sitter spacetime is presented here. By solving exactly the equations of motion for a field, we obtain the dispersion relation of a free particle. It is noticed that the dispersion relation is dependent on the degree of freedom of angular momentum of the particle. We show the threshold anomaly of the ultra high energy cosmic ray disappears naturally in the framework of the de Sitter kinematics.Recent astronomical observations manifest that about two-thirds of the whole energy in the Universe is contributed by a small positive cosmological constant ∧ (＞ 0).Then, an asymptotically de Sitter spacetime is premised naturally. However, physics in the de Sitter spacetime is very different from that in the Minkowski spacetime. As the first step, a covariant formalism of the kinematics in the de Sitter spacetime is presented here.By solving exactly the equations of motion for a field, we obtain the dispersion relation of a free particle. It is noticed that the dispersion relation is dependent on the degree of freedom of angular momentum of the particle. We show the threshold anomaly of the ultra high energy cosmic ray disappears naturally in the framework of the de Sitter kinematics.

关 键 词：ultrahigh energy COSMIC ray  COSMOLOGICAL constant  curved spacetime. 

分 类 号：P172.4[天文地球—天文学]