Modifications to Swisdak (2013)'s rejection sampling algorithm for a Maxwell-Jüttner distribution in particle simulations

Modifications to Swisdak [Phys. Plasmas 20, 062110 (2013)]'s rejection sampling algorithm for drawing a Maxwell-Jüttner distribution in particle simulations are presented. Handy approximations for $e$-folding points and a linear slope in the envelope function are proposed, to make the algorithm self-contained and more efficient.