178 research outputs found
Algebraic characterization of gauge anomalies on a nontrivial bundle
We discuss the algebraic way of solving the descent equations corresponding
to the BRST consistency condition for the gauge anomalies and the Chern--Simons
terms on a nontrivial bundle. The method of decomposing the exterior derivative
as a BRST commutator is extended to the present case.Comment: 15 pages, LaTeX, no figure
Yang-Mills gauge anomalies in the presence of gravity with torsion
The BRST transformations for the Yang-Mills gauge fields in the presence of
gravity with torsion are discussed by using the so-called Maurer-Cartan
horizontality conditions. With the help of an operator \d which allows to
decompose the exterior spacetime derivative as a BRST commutator we solve the
Wess-Zumino consistency condition corresponding to invariant Chern-Simons terms
and gauge anomalies.Comment: 24 pages, report REF. TUW 94-1
The finiteness of the four dimensional antisymmetric tensor field model in a curved background
A renormalizable rigid supersymmetry for the four dimensional antisymmetric
tensor field model in a curved space-time background is constructed. A closed
algebra between the BRS and the supersymmetry operators is only realizable if
the vector parameter of the supersymmetry is a covariantly constant vector
field. This also guarantees that the corresponding transformations lead to a
genuine symmetry of the model. The proof of the ultraviolet finiteness to all
orders of perturbation theory is performed in a pure algebraic manner by using
the rigid supersymmetry.Comment: 23 page
Ghost Equations and Diffeomorphism Invariant Theories
Four-dimensional Einstein gravity in the Palatini first order formalism is
shown to possess a vector supersymmetry of the same type as found in the
topological theories for Yang-Mills fields. A peculiar feature of the
gravitational theory, characterized by diffeomorphism invariance, is a direct
link of vector supersymmetry with the field equation of motion for the
Faddeev-Popov ghost of diffeomorphisms.Comment: LaTex, 10 pages; sign corrected in eq. (3.9); added and completed
reference
Algebraic structure of gravity in Ashtekar variables
The BRST transformations for gravity in Ashtekar variables are obtained by
using the Maurer-Cartan horizontality conditions. The BRST cohomology in
Ashtekar variables is calculated with the help of an operator
introduced by S.P. Sorella, which allows to decompose the exterior derivative
as a BRST commutator. This BRST cohomology leads to the differential invariants
for four-dimensional manifolds.Comment: 19 pages, report REF. TUW 94-1
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