We construct a (1,2) heterotic string with gauge symmetry and determine its particle spectrum. This theory has a local N=1 worldsheet supersymmetry for left movers and a local N=2 worldsheet supersymmetry for right movers and describes particles in either two or three space-time dimensions. We show that fermionizing the bosons of the compactified N=1 space leads to a particle spectrum which has...

I discuss some of the historical circumstances that drove us to use the lattice as a nonperturbative regulator. This approach has had immense success, convincingly demonstrating quark confinement and obtaining crucial properties of the strong interactions from first principles. I wrap up with some challenges for the future.

We study two-dimensional N = (4, 4) supersymmetric gauge theories which do not have classical Higgs branches, but are believed to have isolated quantum Higgs vacua. We provide arguments for the existence of such vacua based on brane dynamics in string theory and the supersymmetric partition sums of the gauge theories.

We study nonlinear cosmological perturbations during the post-inflationary evolution, using the equivalence between a perfect barotropic fluid and a derivatively coupled scalar field with Lagrangian [−(∂φ)2](1+w)/2w. Since this Lagrangian is just a special case of k-inflation, this approach is analogous to the one employed in the study of non-Gaussianities from inflation. We use this method to ...

We study the enhanced gauge symmetries at constant couplings in the moduli space of the Gimon-Polchinski Orientifold. We show that whenever there is a singularity of

I review the results from lattice gauge theory for the masses of exotic hybrid mesons.

Correlations of the topological charge Q, the electric current J and the magnetic current J in SU(2) lattice gauge theory in the Maximal Abelian projection are investigated. It occurs that the correlator ≪ QJJ ≫ is nonzero for a wide range of values of the bare charge. It is shown that: (i) the abelian monopoles in the Maximal Abelian projection are dyons which carry fluctuating electric charge...

Most of the poorly known parameters of the Standard Model cannot be determined without reliable calculations in nonperturbative QCD. Lattice gauge theory provides a first-principles definition of the required functional integrals, and hence offers ways of performing these calculations. This paper reviews the progress in computing hadron spectra and electroweak matrix elements needed to determin...

We consider the space–time variation of gauge couplings in brane world models induced by the coupling to a bulk scalar field. A variation is generated by the running of the gauge couplings with energy and a conformal anomaly while going from the Jordan to the Einstein frame. We indicate that the one-loop corrections cancel implying that one obtains a variation of the fine structure constant by ...

We investigate the lattice gauge theory with fermions at infinite coupling and show that, after formal integration over the fermion fields, it reduces to the Wilson pure gauge theory in the limit when the number of fermion flavours nf approaches infinity. When the boson fields are integrated over instead, the action describes a local theory of Fermi fields only. For finite nf the ferrnion actio...