J.A. Strathdee

On Kaluza-Klein theory

Abstract Assuming the compactification of 4 + K -dimensional space-time implied in Kaluza-Kleintype theories, we consider the case in which the internal manifold is a quotient space, G H . We develop normal mode expansions on the internal manifold and show that the conventional gravitational plus Yang-Mills theory (realizing local G symmetry) is obtained in the leading approximation. The higher terms in the expansions give rise to field theories of massive particles. In particular, for the original Kaluza-Klein 4 + 1-dimensional theory, the higher excitations describe massive, charged, purely spin-2 particles. These belong to infinite dimensional representations of an O (1,2).

Super-gauge transformations

Abstract A systematic method for constructing Wess-Zumino supergauge transformations is exhibited.

Spontaneous compactification in six-dimensional Einstein-Maxwell theory

A discrete set of solutions to the classical Einstein-Maxwell equations in six-dimensional space-time is considered. These solutions have the form of a product of four-dimensional constant curvature space-time with a 2-sphere. The Maxwell field has support on the 2-sphere where it represents a monopole of magnetic charge, n = ±1, ±2, …. The spectrum of massless and massive states is obtained for the special case of flat 4-space, and the solution is shown to be classically stable. The limiting case where the radius of the 2-sphere becomes small is considered and a dimensionally reduced effective lagrangian for the long range modes is derived. This turns out to be an SU(2) × U(1) gauge theory with chiral couplings.

Super-symmetry and non-Abelian gauges

Abstract We show that the conventional Yang-Mills Lagrangian with the Yang-Mills field interacting with Majorana fermions belonging to the adjoint representation of an internal symmetry group like SU(n) is super-gauge invariant.

Nonlinear realizations of space-time symmetries. Scalar and tensor gravity

Abstract The study of conformal group symmetries within the framework of nonlinear realizations is extended and reexpressed in terms of metric tensors and connections on spacetime. The standard Vierbein formalism of general relativity is then reinterpreted in terms of nonlinear realizations of the group GL(4, R). Throughout we emphasise the connection between massless Goldstone bosons and the preferred fields of nonlinear realizations.

An Anomaly Free Model in Six-Dimensions

Abstract We show that a gauged supergravity theory based on E 6 × E 7 × U(1) is free of gauge and gravitational anomalies in six dimensions. It compactifies to (Minkowski) 4 × S 2 by the standard monopole mechanism. With a monopole of strength n in E 6 , the resulting four-dimensional theory exhibits chiral SO(10) × U(1) with 2| n | families (and no antifamilies). Supersymmetry is broken.

The covariant theory of strong interaction symmetries

A classification of particles is suggested based on a Ũ(12) symmetry scheme. This is a relativistic generalization of the U(6) symmetry. The spin 12 and 32 baryons are each described by 20-component spinors which satisfy Bargmann-Wigner equations and belong to the 3̲6̲4̲ representation of the Ũ(12) group while the vector and p. s. mesons belong to the representation 1̲4̲3̲. The procedure for writing fully relativistic form factors is worked out in detail for baryon-meson and meson-meson cases. The new results are the following: (1) FC(q2)FM(q2)∝1+q2<2μ>m, Where Fc and FM are (Sachs) electromagnetic form factors. (2) μD = 1 + 2m/< μ >, where < μ > is the mean mass of the 1- multiplet and m the nucleon mass. (3) μρ,K* = 3. The conventional U(6) results can be recovered by projecting to the positive energy subspace in the rest system for each particle. To any irreducible representation of the U(6) there corresponds one irreducible representation of Ũ(12) and vice versa.

Transition electromagnetic fields in particle physics

Abstract We present a computation of one-loop effective potentials for elementary systems placed in a strong magnetic or a laser-produced electromagnetic environment. This permits a determination in principle of a hierarchy of transition field strengths, for which the systems concerned may (for appropriate values of the parameters in the theory) make transitions from a spontaneously broken asymmetric phase to one of restored symmetry.

On Kaluza-Klein cosmology

Abstract A generalization of Friedmann-Robertson-Walker cosmology to 4 + K dimensions is considered. The space-time manifold R1 × S3 × SK is characterized by two time-dependent scales, R(t) and a(t). The equations of motion for R and a are derived from the 4 + K-dimensional Einstein action supplemented by a one-loop thermal term, corresponding to a gas of non-interacting scalar particles. It is shown that in the approximation when T

Unitary representations of super-gauge symmetries

Abstract A method is given for constructing some of the unitary irreducible representations of the Wess-Zumino super-gauge symmetry. Application of this symmetry to the analysis of S -matrix elements is considered. A new super-gauge symmetry which includes isospin is introduced and some of its representations are constructed.