Related papers: Tachyon couplings on non-BPS D-branes and Dirac-Bo…
We observe a relation between closed strings tachyons and one-loop instabilities in non-supersymmetric non-commutative gauge theories. In particular we analyze the spectra of type IIB string theory on C^3/Z_N orbifold singularities and the…
We discuss tachyon-free examples of (Type IIB on) non-compact non-supersymmetric orbifolds. Tachyons are projected out by discrete torsion between orbifold twists, while supersymmetry is broken by a Scherk-Schwarz phase (+1/-1 when acting…
We investigate the dynamics of a pair of coincident D5 branes in the background of $k$ NS5 branes. It has been proposed by Kutasov that the system with a single probing D-brane moving radially in this background is dual to the tachyonic DBI…
In this article we shall obtain the boundary state associated with a moving $Dp$-brane in the presence of the Kalb-Ramond field $B_{\mu\nu}$, an internal U(1) gauge field $A_{\alpha}$ and a tachyon field, in the compact spacetime. According…
Open string field theory is considered as a tool for deriving the effective action for the massless or tachyonic fields living on D-branes. Some simple calculations are performed in open bosonic string field theory which validate this…
We study the decay of unstable D$p$-branes when the world-volume gauge field is turned on. We obtain the relevant Dp-brane boundary state with electric and magnetic fields by boosting and rotating the rolling tachyon boundary state of a…
We explored a variety of brane configurations in our previous paper within the two derivative truncation of the unstable D9-brane effective theory. In this paper we extend our previous results with emphasis on the inclusion of the higher…
A recently proposed \ell=\infty field theory model of tachyon dynamics for unstable bosonic D-branes has been shown to arise as the two-derivative truncation of (boundary)-string field theory. Using an \ell\to \infty limit appropriate to…
Based on a four point function, the S-matrix elements at disk level of the scattering amplitude of one closed string Ramond-Ramond field ($C$), two tachyons and one scalar field, we find out new couplings in brane anti brane effective…
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…
Non-BPS type II D-branes couple to R-R potentials via an action that, upon tachyon condensation, gives rise to the Wess-Zumino action of BPS D-branes.
Assuming that around the tachyon vacuum the kinetic term of cubic open string field theory is made purely of ghost operators we are led to gauge invariant actions which manifestly implement the absence of open string dynamics around this…
A number of spacetime fields in string theory (notably the metric, dilaton, bosonic and type 0 bulk closed-string tachyon, and bosonic open-string tachyon) have the following property: whenever the spacetime field configuration factorizes…
The gauge-fixed action of a `spacetime-filling' D3-brane with dilaton-axion coupling is formulated in N=1 superspace. We investigate its symmetries by paying special attention to a possible non-linearly realized extra (hidden)…
In this note we propose the use of an alternate action for the open string tachyon on a non-BPS $D3$-brane. At the classical level this action is precisely equivalent to the more commonly used DBI action, but involves an additional coupling…
Dirac-Born-Infeld type effective actions reproduce many aspects of string theory classical tachyon dynamics of unstable Dp-branes. The inhomogeneous tachyon field rolling from the top of its potential forms topological defects of lower…
We extend the usual world-volume action for a Dp-brane to the case of N coincident Dp-branes where the world-volume theory involves a U(N) gauge theory. The guiding principle in our construction is that the action should be consistent with…
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…
By fixing the internal CP factor of tachyon and massless Ramond vertex operators in different pictures, we have shown that the internal CP factor of the disk level S-matrix elements of two fermions and odd number of tachyon vertex operators…
We study the dynamics of a general scalar field, a tachyon or an ordinary scalar, in the presence of world-volume massless fields in the DBI effective theory by exploring their exact solutions. The obtained solutions indicate that the…