Physical problems (microphysics) in relativistic plasma flows

astro-ph/0610345 [abs, ps, pdf, other] :

Title: Physical problems (microphysics) in relativistic plasma flows
Authors: L. O. Silva
Comments: 19 pages, 18 figures

Many problems in astrophysics involve relativistic outflows. The plasma dynamics in these scenarios is critical to determine the conditions for the self-consistent evolution of the fields and particle acceleration. Advances in computer power now allow for kinetic plasma simulations, based on the particle-in-cell (PIC) paradigm, capable of providing information about the role of plasma instabilities in relativistic outflows. A discussion of the key issues associated with PIC simulations is presented, along with some the most important results and open questions, with a particular emphasis on the long time evolution of the filamentation, or Weibel, instability, and on the possible collisionless mechanisms for particle acceleration arising in the collision of relativistic plasma shells.