Holomorphy, Minimal Homotopy and the 4D, N = 1 Supersymmetric Bardeen-Gross-Jackiw Anomaly

By use of a special homotopy operator, we present an explicit, closed-form and simple expression for the left-right Bardeen-Gross-Jackiw anomalies described as the proper superspace integral of a superfunction.Comment: 16 pp, LaTeX, Replacement includes addition comment on WZNW term and one new referenc

Nonabelian Gauge Theories on Noncommutative Spaces

In this paper, we describe a method for obtaining the nonabelian Seiberg-Witten map for any gauge group and to any order in theta. The equations defining the Seiberg-Witten map are expressed using a coboundary operator, so that they can be solved by constructing a corresponding homotopy operator. The ambiguities, of both the gauge and covariant type, which arise in this map are manifest in our formalism.Comment: 14 pages, latex, Talk presented at 2001: A Spacetime Odyssey - Michigan Center for Theoretical Physics, some typos correcte

Black Hole Entropy and the Dimensional Continuation of the Gauss-Bonnet Theorem

The Euclidean black hole has topology $\Re^2 \times {\cal S}^{d-2}$. It is shown that -in Einstein's theory- the deficit angle of a cusp at any point in $\Re^2$ and the area of the ${\cal S}^{d-2}$ are canonical conjugates. The black hole entropy emerges as the Euler class of a small disk centered at the horizon multiplied by the area of the ${\cal S}^{d-2}$ there.These results are obtained through dimensional continuation of the Gauss-Bonnet theorem. The extension to the most general action yielding second order field equations for the metric in any spacetime dimension is given.Comment: 7 pages, RevTe

Gravity, Two Times, Tractors, Weyl Invariance and Six Dimensional Quantum Mechanics

Fefferman and Graham showed some time ago that four dimensional conformal geometries could be analyzed in terms of six dimensional, ambient, Riemannian geometries admitting a closed homothety. Recently it was shown how conformal geometry provides a description of physics manifestly invariant under local choices of unit systems. Strikingly, Einstein's equations are then equivalent to the existence of a parallel scale tractor (a six component vector subject to a certain first order covariant constancy condition at every point in four dimensional spacetime). These results suggest a six dimensional description of four dimensional physics, a viewpoint promulgated by the two times physics program of Bars. The Fefferman--Graham construction relies on a triplet of operators corresponding, respectively to a curved six dimensional light cone, the dilation generator and the Laplacian. These form an sp(2) algebra which Bars employs as a first class algebra of constraints in a six-dimensional gauge theory. In this article four dimensional gravity is recast in terms of six dimensional quantum mechanics by melding the two times and tractor approaches. This "parent" formulation of gravity is built from an infinite set of six dimensional fields. Successively integrating out these fields yields various novel descriptions of gravity including a new four dimensional one built from a scalar doublet, a tractor vector multiplet and a conformal class of metrics.Comment: 27 pages, LaTe

Topological Invariants, Instantons and Chiral Anomaly on Spaces with Torsion

In a spacetime with nonvanishing torsion there can occur topologically stable configurations associated with the frame bundle which are independent of the curvature. The relevant topological invariants are integrals of local scalar densities first discussed by Nieh and Yan (N-Y). In four dimensions, the N-Y form $N= (T^a \wedge T_a - R_{ab} \wedge e^a \wedge e^b)$ is the only closed 4-form invariant under local Lorentz rotations associated with the torsion of the manifold. The integral of $N$ over a compact D-dimensional (Euclidean) manifold is shown to be a topological invariant related to the Pontryagin classes of SO(D+1) and SO(D). An explicit example of a topologically nontrivial configuration carrying nonvanishing instanton number proportional to $\int N$ is costructed. The chiral anomaly in a four-dimensional spacetime with torsion is also shown to contain a contribution proportional to $N$, besides the usual Pontryagin density related to the spacetime curvature. The violation of chiral symmetry can thus depend on the instanton number of the tangent frame bundle of the manifold. Similar invariants can be constructed in D>4 dimensions and the existence of the corresponding nontrivial excitations is also discussed.Comment: 6 pages, RevTeX, no figures, two column

Mass, Confinement and CP Invariance in the Seiberg-Witten Model"

Several physics aspects of the Seiberg-Witten solution of N=2 supersymmetric Yang-Mills theory with SU(2) gauge group, supplemented with a small mass term for the "matter" fields which leads to an $N=1$ theory with confinement, are discussed. The light spectrum of the theory is understood on the basis of current algebra relations, and CP invariance of the massless and massive theories is studied. We find that in the massive (confining) theory the low energy physics has an exact CP symmetry, while in a generic vacuum in the massless theory CP invarince is spontaneously broken.Comment: Latex file, 13 pages, plus 1 eps Figure file (Revised

A Method for Simulating Chiral Fermions on the Lattice

A method for simulating chiral gauge theories on the lattice is proposed, involving zeromodes on a topological defect. Lattice doublers may be decoupled in a gauge invariant manner, and flavor anomalies can be directly observed on a finite lattice. (Requires harvmac)Comment: 10 pages, UCSD-PTH-92-1

Generic chiral superfield model on nonanticommutative N=1/2 superspace

We consider the generic nonanticommutative model of chiral-antichiral superfields on ${\cal N}={1\over 2}$ superspace. The model is formulated in terms of an arbitrary K\"ahlerian potential, chiral and antichiral superpotentials and can include the nonanticommutative supersymmetric sigma-model as a partial case. We study a component structure of the model and derive the component Lagrangian in an explicit form with all auxiliary fields contributions. We show that the infinite series in the classical action for generic nonanticommutative model of chiral-antichiral superfields in D=4 dimensions can be resumed in a compact expression which can be written as a deformation of standard Zumino's lagrangian and chiral superpotential. Problem of eliminating the auxiliary fields in the generic model is discussed and the first perturbative correction to the effective scalar potential is obtained.Comment: 12 pages, LaTeX; text revised and extended, references adde

CPT and Other Symmetries in String/M Theory

We initiate a search for non-perturbative consistency conditions in M theory. Some non-perturbative conditions are already known in Type I theories; we review these and search for others. We focus principally on possible anomalies in discrete symmetries. It is generally believed that discrete symmetries in string theories are gauge symmetries, so anomalies would provide evidence for inconsistencies. Using the orbifold cosmic string construction, we give some evidence that the symmetries we study are gauged. We then search for anomalies in discrete symmetries in a variety of models, both with and without supersymmetry. In symmetric orbifold models we extend previous searches, and show in a variety of examples that all anomalies may be canceled by a Green-Schwarz mechanism. We explore some asymmetric orbifold constructions and again find that all anomalies may be canceled this way. Then we turn to Type IIB orientifold models where it is known that even perturbative anomalies are non-universal. In the examples we study, by combining geometric discrete symmetries with continuous gauge symmetries, one may define non-anomalous discrete symmetries already in perturbation theory; in other cases, the anomalies are universal. Finally, we turn to the question of CPT conservation in string/M theory. It is well known that CPT is conserved in all string perturbation expansions; here in a number of examples for which a non-perturbative formulation is available we provide evidence that it is conserved exactly.Comment: 52 pages.1 paragraph added in introduction to clarify assumption

Dualities of the Matrix Model from T-Duality of the Type II String

We investigate in the Matrix theory framework, the subgroup of dualities of the DLCQ of M-theory compactified on three-tori, which corresponds to T-duality in the auxiliary Type II string theory. We show how these dualities are realized in the supersymmetric Yang-Mills gauge theories on dual noncommutative three-tori.Comment: 37 pages, LaTeX, no figures, typos correcte