Cosmic Plasma Wakefield Acceleration

A cosmic acceleration mechanism is introduced which is based on the wakefields excited by the Alfven shocks in a relativistically flowing plasma. We show that there exists a threshold condition for transparency below which the accelerating particle is collision‐free and suffers little energy loss in the plasma medium. The stochastic encounters of the random accelerating‐decelerating phases results in a power‐law energy spectrum: f(e) ∝ 1/e2. As an example, we discuss the possible production of super‐GZK ultra high energy cosmic rays (UHECR) in the atmosphere of gamma ray bursts. The estimated event rate in our model agrees with that from UHECR observations.