305 research outputs found
Jet coordinates for local BRST cohomology
The construction of appropriate jet space coordinates for calculating local
BRST cohomology groups is discussed. The relation to tensor calculus is briefly
reviewed too.Comment: 11 pages, correction in eq. (29), to appear in Lett.Math.Phy
Local BRST cohomology and covariance
The paper provides a framework for a systematic analysis of the local BRST
cohomology in a large class of gauge theories. The approach is based on the
cohomology of s+d in the jet space of fields and antifields, s and d being the
BRST operator and exterior derivative respectively. It relates the BRST
cohomology to an underlying gauge covariant algebra and reduces its computation
to a compactly formulated problem involving only suitably defined generalized
connections and tensor fields. The latter are shown to provide the building
blocks of physically relevant quantities such as gauge invariant actions,
Noether currents and gauge anomalies, as well as of the equations of motion.Comment: 33 pages, latex 2.09, no figures, introduction extended + minor
modifications; final version, to appear in Commun. Math. Phy
Lectures on supergravity
The text is an essentially self-contained introduction to four-dimensional
N=1 supergravity, including its couplings to super Yang-Mills and chiral matter
multiplets, for readers with basic knowledge of standard gauge theories and
general relativity. Emphasis is put on showing how supergravity fits in the
general framework of gauge theories and how it can be derived from a tensor
calculus for gauge theories of a standard form. Contents: 1. Introduction, 2.
Gauge symmetries in the jet space approach, 3. D=4, N=1 pure supergravity, 4.
Tensor calculus for standard gauge theories, 5. Off-shell formulations of D=4,
N=1 supergravity with matter, A. Lorentz algebra, spinors, Grassmann parity, B.
Explicit verification of local supersymmetry.Comment: 48 pages, lectures given at Mitteldeutsche Physik-Combo 2001/2002;
v2: added terms in eq. (4.28); v3: typos corrected; v4: very minor
improvements in sections 1 and A.2 (reference to Minkowski metric included in
sec. 1, "pseudo Majorana" removed, sign factors included in last 3 eqs. in
sec. A.2
On the determination of anomalies in supersymmetric theories
We develop an efficient technique to compute anomalies in supersymmetric
theories by combining the so-called nonlocal regularization method and
superspace techniques. To illustrate the method we apply it to a four
dimensional toy model with potentially anomalous N=1 supersymmetry and prove
explicitly that in this model all the candidate supersymmetry anomalies have
vanishing coefficients at the one-loop level.Comment: 16 pages, no figures, revtex; no major changes, contents reorganized,
version to appear in Phys. Rev.
Supersymmetry algebra cohomology III: Primitive elements in four and five dimensions
The primitive elements of the supersymmetry algebra cohomology as defined in
a previous paper are computed for standard supersymmetry algebras in four and
five dimensions, for all signatures of the metric and any number of
supersymmetries.Comment: v2: D=4 analysis simplified, D=5 analysis added, refs. added, typos
corrected, 32 page
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