We use dyonic brane configurations of type 0 string theory to study large N non-supersymmetric 4d gauge theories. The brane configurations define theories similar to the supersymmetric ones which arise in type II. We find the non-SUSY analogues of N = 2 and N = 1 . In particular we suggest new non-SUSY CFT’s and a brane realization of a non-SUSY Seiberg duality.

We recall how the Gauss-Bonnet theorem can be interpreted as a finite dimensional index theorem. We describe the construction given in hep-th/0512293 of a function that can be interpreted as a gravitational effective action on a triangulation. The variation of this function under local rescalings of the edge lengths sharing a vertex is the Euler density, and we use it to illustrate how continuo...

We study the effects of additional fields on the unification of gauge couplings in supersymmetric models. We find that the effects are quite constrained by the requirement of SU(5) gauge invariance. In general, we find that any extension of the MSSM will form complete SU(5) multiplets or spoil gauge coupling unification.

A relation between the total instanton number and the quantum-numbers of magnetic monopoles that arise in general Abelian gauges in SU(2) YangMills theory is established. The instanton number is expressed as the sum of the ‘twists’ of all monopoles, where the twist is related to a generalized Hopf invariant. The origin of a stronger relation between instantons and monopoles in the Polyakov gaug...

Using techniques of supersymmetric gauge theories, we present the Ricci-flat metrics on non-compact Kähler manifolds whose conical singularity is repaired by the Hermitian symmetric space. These manifolds can be identified as the complex line bundles over the Hermitian symmetric spaces. Each of the metrics contains a resolution parameter which controls the size of these base manifolds, and the ...

We investigate the dual superconductor mechanism of confinement for pure SU(2) lattice gauge theory in the maximally abelian gauge. We focus on the the dual Meissner effect. We find that the transverse distribution of the longitudinal chromoelectric field due to a static quark-antiquark pair satisfies the dual London equation. Moreover we show that the size of the flux tube scales according to ...

and it is more natural as an averaged gauge field on the link in the continuum theory. We use the analytic method of eigenspace projection operator together with Cardano’s eigenvalue solver for transformation between U and A. It is remarkable that the definition (1) of gauge field allows the same type of formulation of the lattice Landau or Coulomb gauge condition as the continuum theory, i.e.,...

On the lattice some of the salient features of pure gauge theories and of gauge theories with fermions in complex representations of the gauge group seem to be lost. These features can be recovered by considering part of the theory in the continuum. The prerequisite for that is the construction of continuum gauge fields from lattice gauge fields. Such a construction, which is gauge covariant an...

Some problems related to Gribov copies in lattice gauge-fixing and their possible solution are discussed. 1 Gribov and Gauge-Fixing Problem The Faddeev-Popov[1] quantization gives a meaning to the formal (euclidean) expectation value of a gauge invariant observable operator: 〈O〉 = ∫ δA exp[−S(A)] O(A) ∫ δA exp[−S(A)] (1) The Faddeev-Popov method requires the choice of a gauge fixing condition: ...