  In odd-dimensional spaces, gauge invariance permits a Chern-Simons mass term
for the gauge fields in addition to the usual Maxwell-Yang-Mills kinetic energy
term. We study the Casimir effect in such a (2+1)-dimensional Abelian theory.
For the case of parallel conducting lines the result is the same as for a
scalar field. For the case of circular boundary conditions the results are
completely different, with even the sign of the effect being opposite for
Maxwell-Chern-Simons fields and scalar fields. We further examine the effect of
finite temperature. The Casimir stress is found to be attractive at both low
and high temperature. Possibilities of observing this effect in the laboratory
are discussed.
