Title: Energy transfer, pressure tensor and heating of kinetic plasma,
Abstract: Kinetic plasma turbulence cascade spans multiple scales ranging from
macroscopic fluid flow to sub-electron scales. Mechanisms that dissipate large
scale energy, terminate the inertial range cascade and convert kinetic energy
into heat are hotly debated. Here we revisit these puzzles using fully kinetic
simulation. By performing scale-dependent spatial filtering on the Vlasov
equation, we extract information at prescribed scales and introduce several
energy transfer functions. This approach allows highly inhomogeneous energy
cascade to be quantified as it proceeds down to kinetic scales. The pressure
work, $-\left( \boldsymbol{P} \cdot \nabla \right) \cdot \boldsymbol{u}$, can
trigger a channel of the energy conversion between fluid flow and random
motions, which is a collision-free generalization of the viscous dissipation in
collisional fluid. Both the energy transfer and the pressure work are strongly
correlated with velocity gradients.