相关论文: On-shell S-matrix and tachyonic effective actions

We present a supersymmetric action functional for the coupled system of an open fundamental superstring and super-D0-branes attached to (identified with) the string endpoints. As a preliminary step the geometrical actions for a free…

We find that tachyonic orbifold examples of AdS/CFT have corresponding instabilities at small radius, and can decay to more generic gauge theories. We do this by computing a destabilizing Coleman-Weinberg effective potential for twisted…

In a tachyon effective field theory of a non-BPS brane, we construct a classical solution representing a parallel brane-antibrane. The solution is made of a kink and an antikink placed at antipodal points of S^1. Estimation of the brane…

We write the vertex operators of massless NS-NS and RR states of Type II superstring theory in the presence of Orientifold p-planes. They include the usual vertex operators of Type II theory and their images. We then calculate the two-point…

We consider closed string tachyons localized at the fixed points of noncompact nonsupersymmetric orbifolds. We argue that tachyon condensation drives these orbifolds to flat space or supersymmetric ALE spaces. The decay proceeds via an…

The six gluon disk amplitude is calculated in superstring theory. This amplitude probes the gauge interactions with six external legs on Dp-branes, in particular including e.g. F^6-terms. The full string S-matrix can be expressed by six…

A new term in the p-adic world-sheet action is proposed, which couples a constant B-field to the boundary of the world-sheet at disk level. The induced deformation of tachyon scattering amplitudes by star-products is derived. This is in…

It has been conjectured that an extremum of the tachyon potential of a bosonic D-brane represents the vacuum without any D-brane, and that various tachyonic lump solutions represent D-branes of lower dimension. We show that the tree level…

We calculate the background independent action for bosonic and supersymmetric open string field theory in a constant B-field. We also determine the tachyon effective action in the presence of constant B-field.

Recent work has shown that unstable D-branes in two dimensional string theory are represented by eigenvalues in a dual matrix model. We elaborate on this proposal by showing how to systematically include higher order effects in string…

Using the boundary state formalism we obtain the partition function corresponding to a dynamical (rotating-moving) D$p$-brane in the presence of electromagnetic and tachyonic background fields in the superstring theory. The instability of…

We study the world-volume effective action of stable non-BPS branes present in Type II theories compactified on K3. In particular, by exploiting the conformal description of these objects available in the orbifold limit, we argue that their…

We provide a description of the effects of fluxes on euclidean D-brane instantons purely in terms of the 4d effective action. The effect corresponds to the dressing of the effective non-perturbative 4d effective vertex with 4d flux…

We examine the dual correspondence between holographic IIB superstring theory and N=4 super Yang-Mills theory at finite values of the coupling constants. In particular we analyze a field theory strong-coupling expansion which is the S-dual…

This proceeding is based on arXiv:1105.0591 [hep-th] where we consider breaking of supersymmetry in intersecting D-brane configurations by slight deviation of the angles from their supersymmetric values. We compute the masses generated by…

We study time-dependent solutions of Einstein-Maxwell gravity in four dimensions coupled to tachyon matter--the Dirac-Born-Infeld Lagrangian that provides an effective description of a decaying tachyon on an unstable D-brane in string…

We consider breaking of supersymmetry in intersecting D-brane configurations by slight deviation of the angles from their supersymmetric values. We compute the masses generated by radiative corrections for the adjoint scalars on the brane…

In this note we investigate the generalised critical $N=2$ superstrings in $(1,2p)$ spacetime signature. We calculate the four-point functions for the tachyon operators of these theories. In contrast to the usual $N=2$ superstring in…

We investigate the tree-level S-matrix in gauge theories and open superstring theory with several soft particles. We show that scattering amplitudes with two or three soft gluons of non-identical helicities behave universally in the limit,…

We derive pomeron vertex operators for bosonic strings and superstrings in the presence of D-branes. We demonstrate how they can be used in order to compute the Regge behavior of string amplitudes on D-branes and the amplitude of…