Related papers: Fractional Branes and Dynamical Supersymmetry Brea…
String theory and supersymmetry are theoretical ideas that go beyond the standard model of particle physics and show promise for unifying all forces. After a brief introduction to supersymmetry, we discuss the prospects for its experimental…
The fractional supersymmetry chiral algebras in two-dimensional conformal field theory are extended Virasoro algebras with fractional spin currents. We show that associativity and closure of these algebras determines their structure…
Are duality transformations symmetries of string theory? For AdS space-time the answer is no for generic asymptotic values of the moduli, since the duality symmetry is broken explicitly in the dual conformal field theory. In contrast, in…
We consider the type 0 theories, obtained from the closed NSR string by a diagonal GSO projection which excludes space-time fermions, and study the D-branes into these theories. The low-energy dynamics of N coincident D-branes is governed…
We construct supersymmetric brane solutions in string and M-theory with moduli parameters that depend arbitrarily on the light-cone time. Our investigation aims in understanding time dependent phenomena in gauge theories at strong coupling…
We demonstrate how actions for interacting superconformal field theories in (p+1)-dimensions arise as a result of gauge fixing worldvolume diffeomorphisms and fermionic kappa-symmetry in actions for super-p-branes propagating in…
In this note we discuss bound states of un- or meta-stable brane configurations in various non-trivial (curved) backgrounds. We begin by reviewing some known results concerning brane dynamics on group manifolds. These are then employed to…
We study classical dynamics of a probe Dp-brane moving in a background sourced by a stack of Dp-branes. In this context the physics is similar to that of the effective action for open-string tachyon condensation, but with a power-law…
We study brane realizations of chiral matter in N=1 supersymmetric gauge theories in four dimensions. A "cross" configuration which leads to "flavor doubling" is found to have a superpotential. The main example is realized using a special…
Fractional superstrings experience new types of ``internal projections'' which alter or deform their underlying worldsheet conformal field theories. In this talk I summarize some recent results concerning both the worldsheet theory which…
Warped supergravities with lower-dimensional branes provide consistent field-theoretic framework for discussion of important aspects of modern string theory physics. In particular, it is possible to study reliably supersymmetry breakdown…
"Brane supersymmetry breaking" is a peculiar phenomenon that can occur in perturbative orientifold vacua. It results from the simultaneous presence, in the vacuum, of non-mutually BPS sets of BPS branes and orientifolds, which leave behind…
We consider the interplay between brane constructions and type IIA, IIB or M-theory geometries on Calabi-Yau (CY) and G_2 holonomy manifolds. This is related to N=1 (and N=2) gauge theories in four dimensions. We first discuss simple…
Discrete gauge symmetries in global intersecting D-brane models constrain the exact form of the perturbative as well as non-perturbative superpotential. We derive the complete set of conditions on the existence of discrete Zn gauge…
We present special classes of orientifold models involving supersymmetry breaking via branes at angles. Type II superstring theories are compactified on a two torus times a four-dimensional orbifold. Combining worldsheet parity with a…
We construct several dynamical supersymmetry breaking (DSB) models within a single ten-dimensional supersymmetric Yang-Mills (SYM) theory, compactified on magnetized tori with or without orbifolding. We study the case that the supersymmetry…
We include in F-theory, through open Type I F-theory branes (F-branes), string theories with N = 1 supersymmetry, both Type I and heterotic. Type I branes are distinguished from Type II by worldvolume parity projection. The same open Type I…
Dynamical supersymmetry breaking is a fascinating theoretical problem. It is also of phenomenological significance. A better understanding of this phenomenon can help in model building, which in turn is useful in guiding the search for…
The possibility of dynamical electroweak symmetry breaking by strong coupling gauge interaction in models with D-branes in String Theory is examined. Instead of elementary scalar Higgs doublet fields, the gauge symmetry with strong coupling…
We investigate how the presence of RR magnetic $F_{p+2}$ fluxes affects the energy of classical Dp branes, for specific string theory supersymmetric backgrounds which are solutions to the leading order in $\alpha'$ including back-reaction…