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نمایش تعداد 1-10 از 32
Superstring scattering from D-branes
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 amplitudes...
Higher derivative corrections to Wess-Zumino action of Brane-Antibrane systems
By explicit calculation, we show that the expansion of the disk level S-matrix element of one RR field, two open string tachyons and one gauge field that has been recently found corresponds to the derivative expansion of the Wess-Zumino action of D-brane-anti-D-brane...
On the effective action of D-brane-anti-D-brane system
We examine the proposal for constructing the effective action of a D-brane-anti-D-brane system from the non-abelian extension of tachyon DBI action. We consider two prescriptions for the trace in the non-abelian tachyon DBI action. The usual trace...
On T-duality of R2-corrections to DBI action at all orders of gauge field
Recently, it has been observed that in a T-duality invariant world-volume theory in at spacetime, all orders of gauge field strength and all orders of the D-brane velocity appear in two specific matrices. Using these two matrices, we construct...
S-duality of D-brane action at order O(α′2
Using the compatibility of the DBI and the Chern-Simons actions with the T-duality transformations, the curvature corrections to these actions have been recently extended to include the quadratic B-field couplings at ...
Off-shell extension of S-matrix elements and tachyonic effective actions
We show that the on-shell S-matrix elements of four open string massless scalars, two scalars and two tachyons, and four open string tachyons in the super string theory can be written in a unique form. We then propose an ...
More on WZ action of non-BPS branes
We calculate the disk level S-matrix element of one Ramond-Ramond, two gauge fields and one tachyon vertex operators in the world volume of non-BPS branes. We then find the momentum expansion of this amplitude and show ...
On RR couplings on D-branes at order O(a^2
Abstract: Recently, it has been found that there are couplings of the RR field strength
F(p) and the B-field strength H on the world volume of Dp-branes at order O(α′2). These
couplings which have both ...
GRAVITY ON NONCOMMUTATIVE D-BRANES
The effective action for the low energy scattering of two gravitons with a D-brane in the presence of a constant antisytmetric $B$ field in bosonic string theory is calculated and the modification to the standard D-brane action to first order...
Superstring Scattering from D-Branes Bound States
background fields and verify that they correspond to D$p$-brane bound state. Also, from the scattering amplitudes, we calculate the linear coupling of closed string fields to D-brane world-volume and show that they are consistent with Born-Infeld and Chern...