Authors: Subash Adhikari (University of Delaware), Yan Yang (University of Delaware), William H. Matthaeus (University of Delaware)

In this study, we revisit the decomposition of pressure-strain interaction in kinetic plasma turbulence. While pressure dilatation is clearly associated with plasma compressions, using kinetic particle-in-cell (PIC) simulations of decaying turbulence we find that the remaining anisotropic component—commonly referred to as Pi-D—also includes contributions from compressive, non-solenoidal particle velocities. Notably, this compressive component of Pi-D can play a significant role in low plasma beta environments, even when initial density variations are small. Furthermore, we find that the compressive Pi-D is anticorrelated with both its incompressive counterpart and with pressure dilatation.