Related papers: Localized Tachyons and the Quantum McKay Correspon…
It is well known that spherical D-branes are nucleated in the presence of an external RR electric field. Using the description of D-branes as solitons of the tachyon field on non-BPS D-branes, we show that the brane nucleation process can…
The interaction between the intersecting noncommutative D-branes (or membranes) is investigated within the M(atrix) theory. We first evaluate the spectrum of the off-diagonal fluctuation and see that there is a tachyon mode, which signals…
In generalized complex geometry, D-branes can be seen as maximally isotropic spaces and are thus in one-to-one correspondence with pure spinors. When considered on the sum of the tangent and cotangent bundles to the ambient space, all the…
Closed string tachyon condensation has been studied in orbifolds C^2/Z_{N,p} of flat space, using the chiral ring of the underlying N=2 conformal field theory. Here we show that similar phenomena occur in the curved smooth background…
An F-theory dual of a nonsupersymmetric orientifold is considered. It is argued that the condensation of both open and closed string tachyons in the orientifold corresponds to the annihilation of branes and anti-branes in the F-theory dual.…
The mechanism of recombination of intersecting D-branes is investigated within the framework of effective tachyon field theory. We regard the branes as the kink-type tachyon condensed states and use the effective two-tachyon Lagrangian to…
Dvali and Shifman have proposed a field-theoretic mechanism for localizing gauge fields to "branes" in higher dimensional spaces using confinement in a bulk gauge theory. The resulting objects have a number of qualitative features in common…
We study IIA/B string theory compactified on twisted circles. These models possess closed string tachyons and reduce to type 0B/A theory in a special limit. Using methods of gauged linear sigma models and mirror symmetry we construct a…
We construct geometric representatives for the C^2/Z_n fractional branes in terms of branes wrapping certain exceptional cycles of the resolution. In the process we use large radius and conifold-type monodromies, and also check some of the…
Bound states of 7-branes known as 'T-branes' have properties that defy usual geometric intuition. For instance, the gauge group of n coincident branes may not be U(n). More surprisingly, matter may show up at unexpected loci, such as…
We study tachyon condensation on brane-antibrane systems in orbifold theories from the viewpoint of boundary string field theory. We show that the condensation of holomorphic tachyon fields generates various fractional D-branes. The…
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 the lift of certain D6-antiD6-brane systems to M-theory. These are purely gravitational configurations with a bolt singularity. When reduced along a trivial circle, and for large bolt radius, the bolt is related to a…
We review in a pedagogical manner some of the efforts aiming to extend the gauge/gravity correspondence to non-conformal supersymmetric gauge theories in four dimensions. After giving a general overview, we discuss in detail two specific…
We investigate two classes of D-branes in 2-d string theory, corresponding to extended and localized branes, respectively. We compute the string emission during tachyon condensation and reinterpret the results within the $c=1$ matrix model.…
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…
Intersecting D-brane models and their T-dual magnetic compactifications provide an attractive framework for particle physics, allowing for chiral fermions and supersymmetry breaking. Generically, magnetic compactifications have tachyons…
We study recombinations of D-brane systems intersecting at more than one angle using super Yang-Mills theory. We find the condensation of an off-diagonal tachyon mode relates to the recombination, as was clarified for branes at one angle in…
We investigate toric GLSMs as models for tachyon condensation in type II strings on space-time non-supersymmetric orbifold singularities. The A-model correlators in these theories satisfy a set of relations related to the topology of the…
We construct several geometric representatives for the C^n/Z_m fractional branes on either a partially or the completely resolved orbifold. In the process we use large radius and conifold-type monodromies, and provide a strong consistency…