4 research outputs found
A No-Go Theorem for the Nonabelian Topological Mass Mechanism in Four Dimensions
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.Comment: 12 pages, latex fil
Graviton Excitations and Lorentz-Violating Gravity with Cosmological Constant
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 Lorentz-symmetry 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