Related papers: String Loop Corrections to Stable Non-BPS Branes
We introduce a boundary state which is corresponding to a D$p$-brane with tangential dynamics in the presence of the Kalb-Ramond field, a tachyonic field and a $U(1)$ gauge potential in a special gauge. From the interaction of such branes…
The D0/D4 system with a Neveu-Schwarz B-field in the spatial directions of the D4-brane has a tachyon in the spectrum of the (0,4) strings. The tachyon signals the instability of the system to form a bound state of the D0-brane with the…
We obtain the supergravity solution which describes a bound state of D-string/anti-D-string pairs attached to different fixed planes of an orbifold, in type IIB string theory compactified on T^4/Z_2. For parameters at which the conformal…
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…
We determine the spectrum of D-string bound states in various classes of generalized type I vacuum configurations with sixteen and eight supercharges. The precise matching of the BPS spectra confirms the duality between unconventional type…
We extend the analysis of Misaligned Supersymmetry to orientifold vacua. The lack of modular invariance in the Klein bottle, annulus and M\"obius strip amplitudes implies that the IR properties of the physical spectrum are related to the UV…
We study the decay of the unstable D-particle in three-dimensional anti-de Sitter space-time using worldsheet boundary conformal field theory methods. We test the open string completeness conjecture in a background for which the phase space…
A system of k Neveu-Schwarz (NS) 5-branes of type II string theory with one transverse direction compactified on a circle admits various unstable D-brane systems, - some with geometric instability arising out of being placed at a point of…
We analyse the classical decay process of unstable D-branes in superstring theory using the boundary string field theory (BSFT) action. We show that the solutions of the equations of motion for the tachyon field asymptotically approach to…
By explicit evaluation of certain disk S-matrix elements in the presence of background B-flux, we find coupling of two open string tachyons to gauge field, graviton, dilaton or Kalb-Ramond antisymmetric tensor on the world-volume of a…
In type-II string theory compactifications on Calabi-Yau manifolds, topological string theory partition functions give a class of exact F-terms in the four-dimensional effective action. We point out that in the background of constant…
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…
We study bound states of D-p-branes and D-(p+2)-branes. By switching on a large magnetic field F on the (p+2) brane, the problem is shown to admit a perturbative analysis in an expansion in inverse powers of F. It is found that, to the…
We analyse the cosmological implications of brane-antibrane systems in string-theoretic orbifold and orientifold models. In a class of realistic models, consistency conditions require branes and antibranes to be stuck at different fixed…
We consider a D-brane probe in unstable string background associated with flux branes. The twist in spacetime metric reponsible for the supersymmetry breaking is shown to manifest itself in mixing of open Wilson lines with the phases of…
We present a worldvolume effective action suitable for the study of the confined phase of a Dp-anti-Dp system at weak coupling. We identify the mechanism by which the fundamental string arises from this action as a confined electric flux…
When unstable Dp-branes in type II string theory are placed in a B-field, the resulting tachyonic world-volume theory becomes noncommutative. We argue that for large noncommutativity parameter, condensation of the tachyon as a…
We calculate the bosonic boundary state corresponding to a moving fractional D$p$-brane in a partially orbifoldized spacetime $\mathbb{R}^{1, d-5} \times\mathbb{C}^{2}/\mathbb{Z}_{2}$ in the presence of the Kalb-Ramond field, the $U(1)$…
We calculate one-loop 2-point tachyon amplitudes in unoriented open-closed string field theory, and determine all the coupling constants of the interaction vertices in the theory. It is shown that the planar, nonplanar and nonorientable…
We consider tachyonic string-field fluctuations about a Dp-brane background in the geometrical (CFT) formulation of Vacuum String Field Theory. We then extend this analysis to the case of a background B-field. We find that the standard…