We consider recently-constructed solutions of three dimensional SL(N,R)×SL(N,R) Chern-Simons theories with non-relativistic symmetries. Solutions of the Chern-Simons theories can generically be mapped to solutions of a gravitational theory with a higherspin gauge symmetry. However, we will show that some of the non-relativistic solutions are not equivalent to metric solutions, as this mapping f...

We propose a large N dual of 4d, N = 1 supersymmetric, SU(N) Yang-Mills with adjoint field Φ and arbitrary superpotential W (Φ). The field theory is geometrically engineered via D-branes partially wrapped over certain cycles of a non-trivial Calabi-Yau geometry. The large N , or low-energy, dual arises from a geometric transition of the Calabi-Yau, where the branes have disappeared and have bee...

Spontaneous breaking of local Lorentz symmetry occurs when a local vector or tensor field acquires a nonzero vacuum expectation value. The effects of such breaking are examined in the context of gravity theory. These include an associated spontaneous breaking of diffeomorphism symmetry and generation of massless Nambu-Goldstone modes. The possibility of a Higgs mechanism is examined as well, an...

I discuss gauge coupling unification in a class of superstring standard–like models, which are derived in the free fermionic formulation. Recent calculations indicate that the superstring unification scale is at O(10GeV ) while the minimal supersymmetric standard model is consistent with LEP data if the unification scale is at O(10)GeV . A generic feature of the superstring standard–like models...

We show that a modification of the BRST lattice quantization allows to circumvent an old paradox, formulated by Neuberger, related to lattice Gribov copies and nonperturbative BRST invariance. In the continuum limit the usual BRST formulation is recovered. ⋆ Address until August 31st, 1998. ⋆⋆ Permanent address.

In this talk I review some aspects of the idea that there is an infra-red conformal fixedpoint at the TeV scale. In particular, it is shown how gauge coupling unification can be achieved by TeV unification in a semi-simple gauge group.

This Letter addresses a provocative question: “Can the standard electroweak Higgs doublets and their color-triplet partners be the messengers of a low energy gaugemediated SUSY breaking?” Such a possibility does not seem to be immediately ruled out. If so, it can lead to a very economical scheme with clear-cut predictions quite distinct from those of the conventional gauge-mediated scenario. Na...