where jq (which was called jw in the last section) is the probability current density in the coordinate space, and ∇q (which was denoted as ∇ in that sec...where jq (which was called jw in the last section) is the probability current density in the coordinate space, and ∇q (which was denoted as ∇ in that section) is the usual vector operator in the space, while jp is the current density in the momentum space, and ∇p is the similar vector operator in that space:
