15471713
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.
117843456
All Solutions of the Wess-Zumino Consistency Conditions
For the case of a compact gauge group we list all solutions to the Wess-Zumino consistency equations which have to be satisfied by anomalies. We describe the main algebraic tools and theorems required for this complete classification. Our results answer the question whether in nonrenormalizable gauge theories there exist additional up-to-now unknown anomalies in the negative.
13550118
New supersymmetric gauge theories: the double tensor multiplet and its interactions
Abstract The double tensor multiplet of D=4 , N=2 supersymmetry, relevant to type IIB superstring vacua, is derived and its gauge invariant and N=2 supersymmetric interactions are analysed, both self-interactions and interactions with vector multiplets and hypermultiplets. Using deformation theory, it is shown that the lowest dimensional nontrivial interaction vertices of this type have dimension 5 and all dimension 5 vertices are determined. They give rise to new N=2 supersymmetric gauge theories of the `exotic' type which are local but nonpolynomial in some of the fields and coupling constants. Explicit examples of such models are constructed.
116908765
Gauge Covariant Algebras and Local BRST Cohomology
The formulation of the local BRST cohomology on infinite jet bundles and its relation and reduction to gauge covariant algebras are reviewed. As an illustration, we compute the local BRST cohomology for geodesic motion in (pseudo-) Riemannian manifolds and discuss briefly the result (symmetries, constants of the motion, consistent deformations).
13951212
Anomaly candidates and invariants of D = 4, N = 1 supergravity theories
Anomaly candidates and the form of the most general invariant local action are given for old and new minimal supergravity, including the cases that Yang--Mills and chiral matter multiplets are present. Non-minimal supergravity is also discussed. The results are obtained using BRS techniques by solving the descent equations which contain the consistency equation satisfied by integrands of anomalies and invariant actions. Among the anomaly candidates found there are locally supersymmetric extensions of the well known chiral anomalies as well as previously unknown anomaly candidates.
118395460
Nonpolynomial gauge invariant interactions of 1-form and 2-form gauge potentials
A four dimensional gauge theory with nonpolynomial but local interactions of 1-form and 2-form gauge potentials is constructed. The model is a nontrivial deformation of a free gauge theory with nonpolynomial dependence on the deformation parameter (= gauge coupling constant).
120616262
Metric dependence of partition function at high temperature
Abstract This paper is about thermal field theory in a background gravitational field (in space-time which is asymptotically minkowskian). We use the analytically continued imaginary-time formalism in one-loop order, and restrict ourselves to high temperatures. An all-orders, but implicit, expression is given for the partition function.
15405943
Behavior of the thermal gluon self-energy in the Coulomb gauge
We study, to one loop order, the behavior of the gluon self-energy in the noncovariant Coulomb gauge at finite temperature. The cancellation of the peculiar energy divergences, which arise in such a gauge, is explicitly verified in the complete two point function of the Yang-Mills theory. At high temperatures, the leading T{sup 2} term is determined to be transverse and nonlocal, in agreement with the results obtained in covariant gauges. The coefficient of the sub-leading ln(T) contribution is nontransverse but local and coincides (up to a multiplicative constant) with that of the ultraviolet pole term of the zero temperature amplitude.
54656493
Pressure of massless hot scalar theory in the boundary effective theory framework
We use the boundary effective theory approach to thermal field theory in order to calculate the pressure of a system of massless scalar fields with quartic interaction. The method naturally separates the infrared physics, and is essentially nonperturbative. To lowest order, the main ingredient is the solution of the free Euler-Lagrange equation with nontrivial (time) boundary conditions. We derive a resummed pressure, which is in good agreement with recent calculations found in the literature, following a very direct and compact procedure.
118914118
General structure of the photon self-energy in noncommutative QED
We study the behavior of the photon two point function, in noncommutative QED, in a general covariant gauge and in arbitrary space-time dimensions. We show, to all orders, that the photon self-energy is transverse. Using an appropriate extension of the dimensional regularization method, we evaluate the one-loop corrections, which show that the theory is renormalizable. We also prove, to all orders, that the poles of the photon propagator are gauge independent and briefly discuss some other related aspects.
119355685
Forward scattering amplitudes and the thermal operator representation
We develop systematically to all orders the forward scattering description for retarded amplitudes in field theories at zero temperature. Subsequently, through the application of the thermal operator, we establish the forward scattering description at finite temperature. We argue that, beyond providing a graphical relation between the zero temperature and the finite temperature amplitudes, this method is calculationally quite useful. As an example, we derive the important features of the one-loop retarded gluon self-energy in the hard thermal loop approximation from the corresponding properties of the zero temperature amplitude.