Related papers: A stable vacuum of the tachyonic E8 string
We study the rolling tachyon condensate in the presence of a gauge field. The generic vacuum admits both a rolling tachyon, \dot{T}, and a uniform electric field, \vec{E}, which together affect the effective metric governing the…
Intersecting D-brane models and their T-dual magnetic compactifications provide an attractive framework for particle physics, allowing for chiral fermions and supersymmetry breaking. Generically, magnetic compactifications have tachyons…
We discuss the problem of tachyon condensation in the framework of background independent open string field theory. We show, in particular, that the computation of the string field theory action simplifies considerably if one looks at…
The study of discrete gauge symmetries in field theory and string theory is often carried out by embedding them into continuous symmetries. Many symmetries however do not seem to admit such embedding, for instance discrete isometries given…
We study dynamical gaugino condensation in superstring effective theories using the linear multiplet representation for the dilaton superfield. An interesting necessary condition for the dilaton to be stabilized, which was first derived in…
We consider the evolution of FRW cosmological models and linear perturbations of tachyon matter rolling towards a minimum of its potential. The tachyon coupled to gravity is described by an effective 4d field theory of string theory…
We investigate a non-perturbative vacuum in open string field theory expanded around the analytic classical solution which has been found in the universal Fock space generated by matter Virasoro generators and ghost oscillators. We carry…
A class of non-supersymmetric string backgrounds can be constructed using twists that involve space-time fermion parity. We propose a non-perturbative definition of string theory in these backgrounds via gauge theories with supersymmetry…
We study a new mechanism to dynamically break supersymmetry in the E8xE8 heterotic string. As discussed recently in the literature, a long-lived, meta-stable non-supersymmetric vacuum can be achieved in an N=1 SQCD whose spectrum contains a…
We describe a class of 4d N=1 compactifications of the $SO(32)$ heterotic/type I string theory which are destabilized by nonperturbatively generated superpotentials. In the type I description, the destabilizing superpotential is generated…
We study the dynamics of light-like tachyon condensation in a linear dilaton background using level-truncated open string field theory. The equations of motion are found to be delay differential equations. This observation allows us to…
Recently, Hellerman and Schnabl considered the dynamics of unstable D-branes in the background of a linear dilaton. Remarkably, they were able to construct light-like tachyon solutions which interpolate smoothly between the perturbative and…
The study of open string tachyon condensation in string field theory can be drastically simplified by making an appropriate choice of coordinates on the space of string fields. We show that a very natural coordinate system is suggested by…
In four decades of string theory research, only a handful of non-supersymmetric tachyon-free strings with only one neutral scalar at tree level were found. We construct new such non-supersymmetric tachyon-free string theories using…
Recently it was proposed that ten-dimensional tachyonic string vacua may serve as starting points for the construction of viable four dimensional phenomenological string models which are tachyon free. This is achieved by projecting out the…
We present qualitative evidence that closed string tachyon solitons describe backgrounds of lower-dimensional sub-critical string theory. We show that a co-dimension one soliton in the low energy effective gravity-dilaton-tachyon theory in…
Using the linear multiplet formulation for the dilaton superfield, we construct an effective lagrangian for hidden-sector gaugino condensation in string effective field theories with arbitrary gauge groups and matter. Nonperturbative string…
We consider heterotic string compactifications to four dimensions when instantons shrink to zero size. If the standard model gauge group originates from the new gauge symmetry associated with the small instantons singularity, then the…
We find an interesting connection between perturbative large N gauge theory and closed superstrings. The gauge theory in question is found on N D3-branes placed at the tip of the cone R^6/Gamma. In our previous work we showed that, when the…
In this review we describe our current understanding of the properties of open string tachyons on an unstable D-brane or brane-antibrane system in string theory. The various string theoretic methods used for this study include techniques of…