相关论文: Torons and D-Brane Bound States

We discuss some aspects of the physics of branes in the presence of orientifolds and the corresponding worldvolume gauge dynamics. We show that at strong coupling orientifolds sometimes turn into bound states of orientifolds and branes, and…

We study the arbitrariness of boundary conditions (BCs) on $S^1/Z_2$ brane-world models with the gauge group $U(N)$. The BCs are chosen independently on the branes and the bulk in this model. There are numerous choices for BCs in general,…

We study self-dual SU(N) gauge field configurations on the 4 torus with twisted boundary conditions, known as fractional instantons. Focusing on the minimum non-zero action case, we generalize the constant field strength solutions…

We consider a 4+N-dimensional brane world with 2 co-dimension 1 branes in an empty bulk. The two branes have N-1 of their extra dimensions compactified on a sphere S^(N-1), whereas the ordinary 4 spacetime directions are Poincare invariant.…

Bions are multiple fractional instanton configurations with zero instanton charge playing important roles in quantum field theories on a compactified space with a twisted boundary condition. We classify fractional instantons and bions in…

We give a detailed (microscopic) description of the geometric and non-geometric fundamental branes and their bound states in Type II superstring compactifications preserving N=6 supersymmetry. We consider general boundary states that couple…

In these lectures we present a detailed description of the origin and of the construction of the boundary state that is now widely used for studying the properties of D branes. (Lectures given at NATO-ASI on "Quantum Geometry" in Akureyri,…

Some of the properties of string theory defined on world-sheets with boundaries are reviewed. Particular emphasis is put on the possibility of identifying string configurations (\lq D-instantons' and \lq D-branes') that give rise to stringy…

In the presence of a D-brane a string theory develops a new subsector. We show that for curved D-branes the corresponding sector is a (partially twisted) topological field theory. We use this result to compute the degeneracy of 2-branes…

In the D0-D4-brane system, D0-branes do not tunnel. Instead, they form bound states with the D4-brane, whose ground states are exact. However, the D0-brane quantum mechanics contains a BPS instanton. To what does this solution correspond?…

We obtain the most general static intersecting brane solutions by directly solving the relevant equations of motion analytically and in complete generality. These solutions reduce to the known ones in special cases, and contain further a…

We search for integrable boundary conditions and their geometric interpretation as $D$-branes, in models constructed as generalized $\lambda$-deformations of products of group- and coset-spaces. Using the sigma-model approach, we find that…

We study fractional D-branes in the Type-IIA theory on a non-compact orientifold of the orbifold C^3/Z_3 in the boundary state formalism. We find that the fractional D0-branes of the orbifold theory become unstable due to the presence of a…

We study D-branes in SU(2) WZW model by means of the boundary state techniques. We realize the ``fuzzy sphere'' configuration of multiple D0-branes as the boundary state with the insertion of suitable Wilson line. By making use of the…

We analyze certain brane bound states in M-theory and their descendants in type IIA string theory, all involving 3-form or 2-form background fluxes. Among them are configurations which represent NCYM, NCOS and ODp-theories in the scaling…

In this article the action of T-duality on a mixed brane is studied in the boundary state formalism. We also obtain a two dimensional mixed brane with non-zero electric and magnetic fields, from a D$_1$-brane.

We study the effects produced by D-brane instantons on the holomorphic quantities of a D-brane gauge theory at an orbifold singularity. These effects are not limited to reproducing the well known contributions of the gauge theory instantons…

It is pointed out that the energy of the bound states of D-branes and strings is determined by the central charge of the space-time supersymmetry. The universality which is seen at the black hole horizon appears also on the D-brane side:…

This is the first of a series of papers devoted to the group-theoretical analysis of the conditions which must be satisfied for a configuration of intersecting M5-branes to be supersymmetric. In this paper we treat the case of static…

D-branes are string theory solitons defined by boundary conditions on open strings that end on them. They play an important role in the non-perturbative dynamics of string theory and have found a wide range of applications. These lectures…