Collisionless Shock Driven by a Supersonic Velocity Shear
This study simulated a relativistic collisionless velocity shear in an unmagnetized electron-positron plasma using particle-in-cell methods. The simulation showed that the shear flow generates collisionless shocks and magnetic field turbulence by dissipating free energy through the Alfvénic instability (AI). These structures are crucial for particle acceleration, suggesting that Weibel-mediated shocks can inject high-energy particles into the shear acceleration process.