ar X iv : h ep - t h / 95 12 16 8 v 1 2 1 D ec 1 99 5 Positronium States in QED 3

ar X iv : h ep - t h / 94 12 13 6 v 1 1 5 D ec 1 99 4 Relativistically Covariant Symmetry in QED

abstract We construct a relativistically covariant symmetry of QED. Previous local and nonlocal symmetries are special cases. This generalized symmetry need not be nilpotent, but nilpotency can be arranged with an auxiliary field and a certain condition. The Noether charge generating the symmetry transformation is obtained, and it imposes a constraint on the physical states.

ar X iv : h ep - t h / 98 12 13 2 v 1 1 5 D ec 1 99 8 Lorentz and PCT Violating Chern - Simons Term in the Derivative Expansion of QED ∗

We calculate by the method of dimensional regularization and derivative expansion the one-loop effective action for a Dirac fermion with a Lorentz-violating and PCT-odd kinetic term in the background of a gauge field. We show that this term induces a Chern-Simons modification to Maxwell theory. Some related issues are also discussed.

ar X iv : h ep - p h / 99 12 28 8 v 2 1 5 D ec 1 99 9 Lattice Calculations and Hadron Physics

ar X iv : h ep - p h / 95 12 34 7 v 2 2 2 D ec 1 99 5 Correlation between Instantons and QCD - monopoles in the Abelian Gauge

ar X iv : h ep - t h / 98 12 13 2 v 2 3 0 D ec 1 99 8 Lorentz and PCT Violating Chern - Simons Term in the Derivative Expansion of QED ∗

We calculate by the method of dimensional regularization and derivative expansion the one-loop effective action for a Dirac fermion with a Lorentz-violating and PCT-odd kinetic term in the background of a gauge field. We show that this term induces a Chern-Simons modification to Maxwell theory. Some related issues are also discussed.