Echoes of the fifth dimension?

Abstract

In this article we examine the question of whether the highest energy cosmic ray primaries could be ultra relativistic magnetic monopoles. The analysis is performed within the framework of large compact dimensions and TeV scale quantum gravity. Our study indicates that while this hypothesis must be regarded as highly speculative it cannot be ruled out with present data.

Comments: Revised version accepted for publication in Physical Review D. The bibliography has been considerably reduced for the journal version due to limited space