Related papers: Interpolating between open and closed strings - a …
In this lecture notes we explain and discuss some ideas concerning noncommutative geometry in general, as well as noncommutative field theories and string field theories. We consider noncommutative quantum field theories emphasizing an…
Open superstring theory is formulated in terms of a nondegenerate supertranslation algebra. A supercharge for a tachyonic superstring can be also defined classically by taking into account the leakage of the supercurrent which is…
We study decay of unstable D-branes in string theory in the presence of electric field, and show that the classical open string theory results for various properties of the final state agree with the properties of closed string states into…
The multiloop amplitudes for open bosonic string in presence of a constant B-field are derived from first principles. The basic ingredients of the construction are the commutation relations for the string modes and the Reggeon vertex…
In this paper we present two solutions of open bosonic string field theory defined on D0-brane background that correspond to the change of the D0-brane position in the transverse space.
The potential of the closed bosonic bulk tachyon is investigated using $\mathcal{N}~=~1$ closed superstring field theory formulated around Berkovits' and Vafas embedding of the bosonic string into the superstring. From this point of view…
We show how open strings cease to propagate when unstable D-branes decay. The information on the propagation is encoded in BSFT two-point functions for arbitrary profiles of open string excitations. We evaluate them in tachyon condensation…
We derive boundary state of superstring in the open string channel. It describes the superconformal field theory of open string emission and absorption by D-brane. We define the boundary state by conformal mappings from upper half plane…
We study covariant open bosonic string field theories on multiple $Dp$-branes by using the deformed cubic string field theory which is equivalent to the string field theory in the proper-time gauge. Constructing the Fock space…
We study the dynamics of an open membrane with a cylindrical topology, in the background of a constant three form, whose boundary is attached to p-branes. The boundary closed string is coupled to a two form potential to ensure gauge…
Given a D-brane background in string theory (or equivalently boundary conditions in a two-dimensional conformal field theory), classical solutions of open string field theory equations of motion are conjectured to describe new D-brane…
We continue our study of open string perturbation theory on the lightcone worldsheet lattice, which is an $M\times N$ rectangular grid. Here $M$ is the number of $P^+$ units and $N$ is the number of $ix^+$ units. We extend our previous…
We address the problem of describing different closed string backgrounds in background independent open string field theory: A shift in the closed string background corresponds to a collective excitation of open strings. As an illustration…
String vertices of open-closed string field theory on an arbitrary closed string background with $N$ identical D-branes are investigated when $N$ is large. We identify the relevant geometric master equation and solve it using open-closed…
We examine the application of boundary states in computing amplitudes in off-shell open string theory. We find a straightforward generalization of boundary state which produces the correct matrix elements with on-shell closed string states.
We present an exact solution of superstring theory that interpolates in time between an initial type 0 phase and a final phase whose physics is exactly that of the bosonic string. The initial theory is deformed by closed-string tachyon…
We consider twisted tachyons on C/Z_N orbifolds of bosonic closed string theory. It has been conjectured that these tachyonic instabilities correspond to decays of the orbifolds into flat space or into orbifolds with smaller deficit angles.…
We present an exact representation for decaying ZZ-branes within the dual matrix model formulation of c=1 string theory. It is shown how to trade the insertion of decaying ZZ-branes for a shift of the closed string background. Our formlaism…
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…
The tachyonic instability of the open bosonic string is analyzed using the level truncation approach to string field theory. We have calculated all terms in the cubic action of the string field theory describing zero-momentum interactions…