  In this paper we calculate the scale anomaly for a quantum field theoretic
2D-nonrelativistic Bose gas with contact interactions using Fujikawa's method,
both in vacuum and in many-body systems. The use of path integrals for these
problems is novel and motivated by a recently developed path-integral framework
for addressing questions about scaling in these systems. A natural class of
regulators is found that produces the correct value of the anomaly
traditionally calculated via other methods, e.g., diagrammatically via the beta
function.
