Classical three dimensional Yang-Mills is seen to be related to the topological Chern-Simons term through a nonlinear but fully local and covariant gauge field redefinition. A classical recursive cohomological argument is provided.Comment: 8 pages, LateX2e fil

We prove that there is no power-counting renormalizable nonabelian generalization of the abelian topological mass mechanism in four dimensions. The argument is based on the technique of consistent deformations of the master equation developed by G. Barnich and one of the authors. Recent attempts involving extra fields are also commented upon.

Motivated by the interest raised by the problem of Lorenz-symmetry violating gauge theories in connetion with gravity models, this contribution sets out to provide a general method to systematically study the excitation spectrum of gravity actions which include a Lorentzsymmetry breaking Chern-Simons-type action term for the spin connection. A complete set of spin-type operators is found which accounts for the (Lorentz) violation parameter to all orders and graviton propagators are worked out in a number of different situations.

We present here the zero curvature formulation for a wide class of field theory models. This formalism, which relies on the existence of an operator δ which decomposes the exterior space-time derivative as a BRS commutator, turns out to be particularly useful in order to solve the Wess-Zumino consistency condition. The examples of the topological theories and of the B-C string ghost system are considered in detail.2 In the case of gravitational theories, the decomposition d = − [b, δ] was in fact already observed, see for instance refs. [5,6].3 The nilpotency of d is a direct consequence of the zero curvature condition (1.6).

The purpose of this work is to present a model for 3D massive gravity with topological and higher-derivative terms. Causality and unitarity are discussed at tree-level. Power-counting renormalizability is also contemplated.Comment: 9 pages, Latex, no figures; to be published in Gen. Rel. Gra