Recent Results on N=2,4 Supersymmetry with Lorentz Symmetry Violating

An introduction to Seiberg-Witten theory and its relation to theories which include gravity.

We present an explicit formulation of supersymmetric Yang-Mills theories from $\D=$ 5 to 10 dimensions in the familiar $\N=1,\D=4$ superspace. This provides the rules for globally supersymmetric model building with extra dimensions and in particular allows us to simply write down $\N=1$ SUSY preserving interactions between bulk fields and fields localized on branes. We present a few applications of the formalism by way of illustration, including supersymmetric ``shining'' of ...

Field models with $n$ extra spatial dimensions have a larger $SO(1,3+n)$ Lorentz symmetry which is broken down to the standard $SO(1,3)$ four dimensional one by the compactification process. By considering Lorentz violating operators in a $5D$ supersymmetric Wess-Zumino mo\-del, which otherwise conserve the standard four dimensional Poincare invariance, we show that supersymmetry can be restored upon a simple deformation of the supersymmetric transformations. However, supersy...

A ten-dimensional supersymmetric gauge theory is written in terms of N=1, D=4 superfields. The theory is dimensionally reduced over six-dimensional coset spaces. We find that the resulting four-dimensional theory is either a softly broken N=1 supersymmetric gauge theory or a non-supersymmetric gauge theory depending on whether the coset spaces used in the reduction are non-symmetric or symmetric. In both cases examples susceptible to yield realistic models are presented.

An action with unconventional supersymmetry was introduced in an earlier paper. Here it is shown that this action leads to standard physics for fermions and gauge bosons at low energy, but to testable extensions of standard physics for fermions at high energy and for fundamental bosons which have not yet been observed. For example, the Lorentz-violating equation of motion for these bosons implies that they have spin 1/2.

We present a formulation of the maximally supersymmetric N=4 gauge theory in Lorentz harmonic chiral (LHC) superspace. It is closely related to the twistor formulation of the theory but employs the simpler notion of Lorentz harmonic variables. They parametrize a two-sphere and allow us to handle efficiently infinite towers of higher-spin auxiliary fields defined on ordinary space-time. In this approach the chiral half of N=4 supersymmetry is manifest. The other half is realiz...

The aim of these notes is to provide a short introduction to supersymmetric theories: supersymmetric quantum mechanics, Wess-Zumino models and supersymmetric gauge theories. A particular emphasis is put on the underlying structures and non-perturbative effects in N=1, N=2 and N=4 Yang-Mills theories. (Extended version of lectures given at the TROISIEME CYCLE DE LA PHYSIQUE EN SUISSE ROMANDE)

We show that the $N=2$ superstrings may be viewed as a special class of the $N=4$ superstrings and demonstrate their equivalence. This allows us to realize all known string theories based on linear algebras and with $N<4$ supersymmetries as special choices of the vacua in the $N=4$ superstring.

We propose a systematic way of constructing $N=2, d=4$ superfield Born-Infeld action with a second nonlinearly realized N=2 supersymmetry. The latter, together with the manifest N=2 supersymmetry, form a central-charge extended $N=4, d=4$ supersymmetry. We embed the Goldstone-Maxwell N=2 multiplet into an infinite-dimensional off-shell supermultiplet of this N=4 supersymmetry and impose an infinite set of covariant constraints which eliminate all extra N=2 superfields through...

Spacetime superalgebras with 64 or less number of real supercharges, containing the type IIB Poincare superalgebra in (9,1) dimensions and the N=1 Poincare superalgebra in (10,1) are considered. The restriction D<14, and two distinct possibilities arise: The N=(1,0) superalgebra in (11,3) dimensions, and the N=(2,0) superalgebra in (10,2) dimensions. Emphasizing the former, we describe superparticle and super Yang-Mills systems in (11,3) dimensions. We also propose an N=(2,1)...