Structure of radiatively induced Lorentz and CPT violation in QED at finite temperature - art. no. 105003

We obtain the induced Lorentz- and CPT-violating term in QED at finite temp erature using the imaginary-time formalism and dimensional regularization. Its form resembles a Chem-Simons-like structure, but, unexpectedly, it does not depend on the temporal component of the fixed b(mu) constant vector th at is coupled to the axial-vector current. Nevertheless, Ward identities ar e respected and its coefficient vanishes at T = 0, consistent with previous computations with the same regularization procedure, and it is a nontrivia l function of temperature. We argue that at finite T a Chern-Simons-like Lo rentz- and CPT-violating term is generically present, the value of its coef ficient being unambiguously determined up to a T-independent constant, rela ted to the zero-temperature renormalization conditions.