16321193
Structure of BRS-Invariant Local Functionals
For a large class of gauge theories a nilpotent BRS-operator $s$ is constructed and its cohomology in the space of local functionals of the off-shell fields is shown to be isomorphic to the cohomology of $\4s=s+d$ on functions $f(\4C,\PH)$ of tensor fields $\PH$ and of variables $\4C$ which are constructed of the ghosts and the connection forms. The result allows general statements about the structure of invariant classical actions and anomaly candidates whose BRS-variation vanishes off-shell. The assumptions under which the result holds are thoroughly discussed.
13550118
New supersymmetric gauge theories: the double tensor multiplet and its interactions
Abstract The double tensor multiplet of D=4 , N=2 supersymmetry, relevant to type IIB superstring vacua, is derived and its gauge invariant and N=2 supersymmetric interactions are analysed, both self-interactions and interactions with vector multiplets and hypermultiplets. Using deformation theory, it is shown that the lowest dimensional nontrivial interaction vertices of this type have dimension 5 and all dimension 5 vertices are determined. They give rise to new N=2 supersymmetric gauge theories of the `exotic' type which are local but nonpolynomial in some of the fields and coupling constants. Explicit examples of such models are constructed.
118395460
Nonpolynomial gauge invariant interactions of 1-form and 2-form gauge potentials
A four dimensional gauge theory with nonpolynomial but local interactions of 1-form and 2-form gauge potentials is constructed. The model is a nontrivial deformation of a free gauge theory with nonpolynomial dependence on the deformation parameter (= gauge coupling constant).
13951212
Anomaly candidates and invariants of D = 4, N = 1 supergravity theories
Anomaly candidates and the form of the most general invariant local action are given for old and new minimal supergravity, including the cases that Yang--Mills and chiral matter multiplets are present. Non-minimal supergravity is also discussed. The results are obtained using BRS techniques by solving the descent equations which contain the consistency equation satisfied by integrands of anomalies and invariant actions. Among the anomaly candidates found there are locally supersymmetric extensions of the well known chiral anomalies as well as previously unknown anomaly candidates.
117843456
All Solutions of the Wess-Zumino Consistency Conditions
For the case of a compact gauge group we list all solutions to the Wess-Zumino consistency equations which have to be satisfied by anomalies. We describe the main algebraic tools and theorems required for this complete classification. Our results answer the question whether in nonrenormalizable gauge theories there exist additional up-to-now unknown anomalies in the negative.
116908765
Gauge Covariant Algebras and Local BRST Cohomology
The formulation of the local BRST cohomology on infinite jet bundles and its relation and reduction to gauge covariant algebras are reviewed. As an illustration, we compute the local BRST cohomology for geodesic motion in (pseudo-) Riemannian manifolds and discuss briefly the result (symmetries, constants of the motion, consistent deformations).
54493955
Quantum statistical correlations in thermal field theories: Boundary effective theory
We show that the one-loop effective action at finite temperature for a scalar field with quartic interaction has the same renormalized expression as at zero temperature if written in terms of a certain classical field {phi}{sub c}, and if we trade free propagators at zero temperature for their finite-temperature counterparts. The result follows if we write the partition function as an integral over field eigenstates (boundary fields) of the density matrix element in the functional Schroedinger field representation, and perform a semiclassical expansion in two steps: first, we integrate around the saddle point for fixed boundary fields, which is the classical field {phi}{sub c}, a functional of the boundary fields; then, we perform a saddle-point integration over the boundary fields, whose correlations characterize the thermal properties of the system. This procedure provides a dimensionally reduced effective theory for the thermal system. We calculate the two-point correlation as an example.
118914118
General structure of the photon self-energy in noncommutative QED
We study the behavior of the photon two point function, in noncommutative QED, in a general covariant gauge and in arbitrary space-time dimensions. We show, to all orders, that the photon self-energy is transverse. Using an appropriate extension of the dimensional regularization method, we evaluate the one-loop corrections, which show that the theory is renormalizable. We also prove, to all orders, that the poles of the photon propagator are gauge independent and briefly discuss some other related aspects.
14070716
Absence of higher order corrections to the non-Abelian Chern–Simons coefficient
Abstract We extend the Coleman–Hill analysis to non-Abelian Chern–Simons theories containing a tree level topological mass term. We show, in the case of a pure Yang–Mills–Chern–Simons theory, that there are no corrections to the coefficient of the Chern–Simons term beyond one loop in the axial gauge. Our arguments use constraints coming only from small gauge Ward identities as well as the analyticity of the amplitudes, much like the proof in the Abelian case. Some implications of this result are also discussed.
119534920
Factorization of finite temperature graphs in thermal QED
We extend our previous analysis of gauge and Dirac fields in the presence of a chemical potential. We consider an alternative thermal operator which relates in a simple way the Feynman graphs in QED at finite temperature and charge density to those at zero temperature but nonzero chemical potential. Several interesting features of such a factorization are discussed in the context of the thermal photon and fermion self-energies.
125687040
Finite temperature gluon self-energy in a class of general temporal gauges