High-energy end of the cosmic-ray spectrum has provided us to check a validity of the Lorentz Invariance and the Relativity principle, through the observation of the so-called GZK cutoff. It is claimed in this report that the comoving reference frame in the expanding universe might define the preferable inertia frame, in contradiction to the relativity principle. If the present universe has bee...

The clustering of ultra high energy cosmic ray events suggests that they have originated from compact sources. One of the possible physical mechanisms by which ultra high energy nuclei reach the Earth from far away astrophysical sources (quasars or BL Lac objects) evading the Greisen-Zatsepin-Kuzmin (GZK) cut-off is by violation of Lorentz invariance. Assuming that there is violation of Lorentz...

A Lorentz-noninvariant modification of the kinematic dispersion law was proposed in Ref [1], claimed to be derivable from from q-deformed noncommutative theory, and argued to evade ultrahigh energy threshold anomalies (trans-GKZ-cutoff cosmic rays and TeV-photons) by raising the respective thresholds. It is pointed out that such dispersion laws do not follow from deformed oscillator systems, an...

در این تحقیق به مقایسه تحلیلی و عددی آبشار جریان برگشتی مدل R با آبشارهای Q QI سیستم‌­های چندجزیی پایدار پرداخته می‌­شود. راستا برای اولین بار کدهای جهت طراحی منظور کد نرم‌افزار متلب نوشته شده‌­اند. نتایج نشان می‌­دهد که دو جزء 1k 2k از خوراک Nc جزء، تعداد معدودی قابل تعریف است همگی حالات خاصی می­‌باشد. هم‌­چنین یافته‌­ها مجموع مقدار برش جزیی همیشه برابر یک است. طریق داده می‌­شود صورتی میانگین ...

The source, origin, and acceleration mechanisms of ultra-high-energy cosmic rays (UHECR) (E>1020 eV, beyond the GZK limit) remain uncertain unclear. main explanations are associated with particular mechanisms, such as Fermi mechanism, in which charged particles could be accelerated by clouds magnetized gas moving within our Galaxy, or magnetic reconnection field lines at, e.g., core high-ene...