arXiv subjects
Publications and source records attributed to Dietmar Mülsch.
The Blau-Thompson N_T=2, D=3 nonequivariant topological model is extended to a N_T=4, D=3 topological theory. The latter, formally, may be regarded as a topological deformation of the N_T=2, D=4 Yamrom-Vafa-Witten theory after dimensional reduction to D=3. For completeness, also the dimensional reduction of the half-twisted N_T=2, D=4 Yamron model is explicitly constructed.
We study the renormalizability of (massive) topological QCD based on the algebraic BRST technique by adopting a non-covariant Landau type gauge and making use of the full topological superalgebra. The most general local counter terms are determined and it is shown that in the presence of central charges the BRST cohomology remains trivial. By imposing an additional set of stability constraints it is proven that the matter action of topological QCD is perturbatively finite.
A superspace formulation is proposed for the osp(1,2)-covariant Lagrangian quantization of general massive gauge theories. The superalgebra os0(1,2) is considered as subalgebra of sl(1,2); the latter may be considered as the algebra of generators of the conformal group in a superspace with two anticommuting coordinates. The mass-dependent (anti)BRST symmetries of proper solutions of the quantum master equations in the osp(1,2)-covariant formalism are realized in that superspace as invariance under translations combined with mass-dependent special conformal transformations. The Sp(2) symmetry - in particular the ghost number conservation - and the "new ghost number" conservation are realized as invariance under symplectic rotations and dilatations, respectively. The transformations of the gauge fields - and of the full set of necessarily required (anti)ghost and auxiliary fields - under the superalgebra sl(1,2) are determined both for irreducible and first-stage reducible theories with closed gauge algebra.
In the framework of osp(1,2)-symmetric quantization of irreducible massive gauge theories the background field method is studied for the simplest case of a linear splitting of the gauge field into a background configuration and the quantum fluctuations. The symmetries of that approach - including three types of background-dependent gauge transformations - are expressed by Ward identities. From these identities together with the equations of motion of the auxiliary field the background dependence of the vertex functions and of the Greens functions is determined. It is proven that the introduction of a background field does not change the ultraviolet asymptotics of the theory.