An Introduction to Particle Acceleration in Shearing Flows

Understand

Shear flows are ubiquitously present in space and astrophysical plasmas.

• This paper highlights the central idea of the non-thermal acceleration of charged particles in shearing flows and reviews some of the recent developments.
• Topics include the acceleration of charged particles by microscopic instabilities in collisionless relativistic shear flows, Fermi-type particle acceleration in macroscopic, gradual and non-gradual shear flows, as well as shear particle acceleration by large-scale velocity turbulence.
• When put in the context of jetted astrophysical sources such as Active Galactic Nuclei, the results illustrate a variety of means beyond conventional diffusive shock acceleration by which power-law like particle distributions might be generated.