Particle acceleration in relativistic astrophysical plasmas

Relativistic astrophysical objects often display evidence of very efficient particle acceleration, such as X-ray and gamma-ray nonthermal emission and are widely recognized as potential sources of cosmic rays. Elucidating the physical mechanisms that turn these environments into such formidable particle accelerators is a longstanding problem of high-energy astrophysics.

In this talk, I will briefly explain why shocks and turbulence, naturally expected to occur in these environments, could play an essential role in the acceleration of particles. I will then discuss some of the challenges that poses the description of these nonlinear processes, especially in the context of high-energy astrophysical sources, which involve astronomical ranges of scales and physical conditions much more extreme than we can probe in our laboratories or in the Solar system. Finally, I will share some recent results from my simulations.