相关论文: Superstring Scattering from D-Branes Bound States
We derive fully covariant expressions for all two-point scattering amplitudes of two massless closed strings from a Dirichlet $p$-brane. This construction relies on the observation that there is a simple relation between these D-brane…
Method for computing scattering amplitudes of open strings with Dirichlet boundary on one end and Neumann boundary condition on the other is described. Vertex operator for these states are constructed using twist fields which have been…
We derive fully covariant expressions for all two-point scattering amplitudes involving closed string tachyon and massless strings from Dirichlet brane in type 0 theories. The amplitude for two massless D-brane fluctuations to produce…
We study in detail the procedure for obtaining couplings of D-branes to closed string fields by evaluating string theory disc amplitudes. We perform a careful construction of the relevant vertex operators and discuss the effects of…
We consider two Dirichlet p-branes with lower dimensional brane charges and their scattering. We first calculate the cylinder amplitude of open string with suitable boundary conditions. We compare this result with that in the IIB matrix…
We develop an operator formalism to compute scattering amplitudes of arbitrary bosonic string states in the background of many D-branes. Specifically, we construct a suitable boundary state which we use to saturate the multi-Reggeon vertex…
We examine in detail various string scattering amplitudes in order to extract the world-volume interactions of massless fields on a Dirichlet brane. We find that the leading low-energy interactions are consistent with the Born-Infeld and…
In this article we consider open strings with mixed boundary conditions (a combination of Neumann and Dirichlet conditions at each end). We discuss how their end points show a $D_p$-brane with NS-NS charge, i.e. a bound state of a D-brane…
We develop the general formalism of string scattering from decaying D-branes in bosonic string theory. In worldsheet perturbation theory, amplitudes can be written as a sum of correlators in a grand canonical ensemble of unitary random…
Closed string dynamics in the presence of noncommutative Dp-branes is investigated. In particular, we compute bulk closed string two-point scattering amplitudes; the bulk space-time geometries encoded in the amplitudes are shown to be…
At the tree level, the scattering processes involving open and closed strings are described by a disk world-sheet with vertex operator insertions at the boundary and in the bulk. Such amplitudes can be decomposed as certain linear…
We compute the amplitude for the radiation of massless NS-NS closed string states from the interaction of two moving D-branes. We consider particle-like D-branes with reference to 4-dimensional spacetime, in toroidal and orbifold…
We study scatterings of bosonic massive closed string states at arbitrary mass levels from D-brane. We discover that all the scattering amplitudes can be expressed in terms of the generalized hypergeometric function with special arguments,…
In this thesis we discuss some nonperturbative and noncommutative aspects of string theory. We present low-energy background field solutions corresponding to various D-branes (and their bound states) and intersecting branes in flat and…
In this article, applying different types of boundary conditions; Dirichlet, Neumann, or Mixed, on open strings we realize various new brane bound states in string theory. Calculating their interactions with other D-branes, we find their…
In {\em Phys.\ Lett.} {\bf B 660}, 583 (2008), it was proposed that the D-brane geometry could be produced by open string quantum effects. In an effort to verify the proposal, we consider scattering amplitudes involving {\em massive} open…
We derive compact expressions for one-loop scattering amplitudes of four open-string vector bosons around supersymmetric configurations with intersecting or magnetized D-branes on toroidal orbifolds. We check the validity of our formulae…
We study the tree level scattering or emission of n closed superstrings from a decaying non-BPS brane in Type II superstring theory. We attempt to calculate generic n-point superstring disk amplitudes in the rolling tachyon background. We…
We study D-branes in the extended geometry appearing in exceptional field theory (or exceptional generalised geometry). Starting from the exceptional sigma model (an $E_{d(d)}$ covariant worldsheet action with extra target space…
We study various aspects of D-branes in the two families of closed N=2 strings denoted by \alpha and \beta in hep-th/0211147. We consider two types of N=2 boundary conditions, A-type and B-type. We analyse the D-branes geometry. We compute…