Radiatively Induced Lorentz and CPT Violation in QED at Finite   Temperature
  In this paper we evaluate the induced Lorentz and CPT violating Chern-Simons term in the QED action at finite temperature. We do this using the method of derivative expansion of fermion determinants. Also, we use the imaginary-time formalism to calculate the temperature dependence of the Chern-Simons term 
J. R. S. Nascimento (UFPB), R. F. Ribeiro (UFPB) and N. F. Svaiter   (CBPF)