On the Chern-Simons Gauge Field

We show the relationship between a fluid of particles having charge and magnetic moment in $2+1$ dimensional electromagnetism and the Chern-Simons statistical field. The matter current which is minimally coupled to the electromagnetic field has two parts: the global electromagnetic current, and the corresponding topological current. The topological current is associated to the induced electromagnetic current, via a simple constitutive relation between charges and magnetic moments. We also study the edge states, when the region that the currents occupy is bounded.